Fundamental of Environmental Science

SQOE I FUNDAMENTALS OF ENVIRONMENTAL SCIENCE (Integrated Water Resources Management) Dr. Ho Wei Seng Wong Sin Yeng Chng Loi Peng

Project Directors:

Prof. Dr. Mansor Fadzil Prof. Dr. Mohd Kidin Shahran Open University Malaysia (OUM)

Module Writers:

Dr. Ho Wei Seng Wong Sin Yeng Universiti Malaysia Sarawak (UNIMAS) Chng Loi Peng Open University Malaysia (OUM)

Moderators:

Prof. Dr. T. K. Mukherjee Open University Malaysia (OUM) Dr. Harinder Rai Singh Universiti Teknologi MARA (UiTM) Dr. Anton Espira

Develop by:

Centre for Instructional Design and Technology (CIDT) Open University Malaysia

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Meteor Doc. Sdn. Bhd. Lot 47-48, Jalan SR 1/9, Seksyen 9, Jalan Serdang Raya, Taman Serdang Raya, 43300 Seri Kembangan, Selangor Darul Ehsan

First Printing, September 2005 Second Printing, March 2009 Copyright @ Open University Malaysia (OUM), March 2009, SQOE I All rights reserved. No part of this work may be reproduced in any form or by any means without the written permission of the President, Open University Malaysia (OUM). Version March 2009

Table of Contents Course Guide

ix-xv

Topic 1

Ecosystem 1.1 Classification of Ecosystem 1.1.1 Biogeographical Regions 1.1.2 Life Zones 1.1.3 Biomes 1.1.4 Ecoregions 1.2 Terrestrial Ecosystem 1.2.1 Grasslands and Savannas 1.2.2 Shrublands and Deserts 1.2.3 Tundra and Taiga 1.2.4 Forest (Temperate, Tropical and Mangrove) 1.3 Aquatic Ecosystem 1.3.1 Freshwater 1.3.2 Marine Summary Key Terms Test 1 Test 2 References

1 2 2 3 5 6 6 7 8 9 11 15 15 18 21 21 21 23 24

Topic 2

Land Use and Conservation 2.1 Land Resources and Conservation 2.1.1 Agricultural Lands 2.1.2 Rangelands 2.1.3 Wilderness and Forests 2.1.4 Wetlands 2.2 Urban Land Use 2.2.1 Urbanization and Urban Growth 2.2.2 Transportation and Urban Development 2.2.3 Urban Land Use Planning Summary Key Terms Test 1 Test 2 References

25 26 26 28 30 34 35 36 38 39 41 42 42 44 44

iv X TABLE OF CONTENTS

Topic 3

Environmental Degradation 3.1 Air Pollution 3.1.1 Sources of Air Pollution 3.1.2 Where Do Air Pollutants Go? 3.1.3 Impact of Air Pollution on Humans 3.1.4 Acidification 3.1.5 Air Pollution Control Efforts 3.2 Water Resources Pollution 3.2.1 Sources of Water Pollution 3.2.2 Impact of Water Pollution 3.2.3 Water Control Efforts 3.3 Solid and Hazardous Waste 3.3.1 Municipal Solid Waste 3.3.2 Wastewater 3.3.3 Hazardous Waste 3.3.4 Waste Management 3.3.5 Advanced Treatment of Wastes 3.4 Noise Pollution 3.4.1 Sources of Noise 3.4.2 Effects of Noise Pollution 3.4.3 Controlling Noise Pollution Summary Key Terms Test 1 Test 2 References

46 46 47 48 49 50 51 52 53 53 56 56 56 57 57 58 59 60 60 62 63 63 64 64 66 67

Topic 4

Global Environmental Issues 4.1 Atmosphere 4.1.1 What is Ozone? 4.1.2 Importance of Ozone 4.1.3 Ozone Formation 4.1.4 Causes of Ozone Depletion 4.1.5 Ozone Depletion Process 4.1.6 Ozone Destruction by Chlorofluorocarbons 4.1.7 The Ozone Hole 4.1.8 Impact of Ozone Depletion 4.2 Global Warming 4.2.1 Greenhouse Effect 4.2.2 Climate Change 4.2.3 Potential Impacts of Climate Change for Tropical Asia 4.3 Sea Level Rise 4.3.1 Effects of Sea Level Rise Summary

68 69 71 71 71 72 73 74 75 75 76 76 78 79 82 82 83

TABLE OF CONTENTS W v

Topic 5

Topic 6

Key Terms Test 1 Test 2 References

84 84 86 87

Environment Management Policy and Regulation 5.1 Malaysian Environmental Legislation 5.1.1 Ministry of Science, Technology and Innovations 5.1.2 Environmental Quality Act 1974 5.1.3 Malaysia Environmental Policy 5.1.4 National Biodiversity Policy 5.2 Environmental Impact Assessment 5.2.1 Important Players in the EIA 5.2.2 Approval of the EIA Report 5.3 Environmental Programmes by the Malaysian Government 5.3.1 Recycling 5.3.2 National CFC Phase-Out Plan 5.4 Efforts of NGOs and Private Orginizations in Combating Environmental Problems 5.4.1 Malaysian Nature Society 5.4.2 Sahabat Alam Malaysia (SAM) 5.4.3 Centre for Environment, Technology and Development, Malaysia 5.5 International Cooperations 5.5.1 Convention on Climate Change 5.5.2 Vienna Convention 5.5.3 Basel Convention 5.6 Alternative Methods to Sustain the Environment 5.6.1 Green Vehicle 5.6.2 Government Incentives 5.6.3 Carbon Sinks Summary Key Terms Test 1 Test 2 References

88 89 89 90 90 91 92 92 93 94 94 95 96

98 98 101 103 104 104 104 105 105 105 106 107 108

Water Pollution and Water Treatment 6.1 Chemistry of Water Pollution 6.1.1 Organic Oxygen-demanding Wastes 6.1.2 Toxic Metals 6.1.3 Organochlorine 6.1.4 Thermal Pollution 6.1.5 Radionuclides

109 110 112 115 117 119 121

96 97 97

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6.2

Water and Waste Water Treatment 6.2.1 Water Treatment Plant 6.2.2 Sewage Treatment Summary Test 1 Test 2

123 123 124 128 128 129

COURSE GUIDE

INTRODUCTION This reading material is designed for learners seeking admission into the Master of Environmental Science (IWRM) programme as an open entry student. The course material in environmental biology, and water pollution, which includes discussion are fundamental to many of the courses in the M.Sc. (IWRM) programme, prepared by a group of senior experts of public universities and OUM. A thorough reading of this module for several times will enable the learners to grasp the course material and self-formulate multiple choice questions, similar to a few examples given for the topics inside the module.

COURSE OBJECTIVE The objectives of this course are to enable learners to: 1.

understand the structure and function of biotic and abiotic components present in an ecosystem.

2.

know the importance of land resource management, urban land use and planning, and urbanisation.

3.

relate how human activities influence the environment.

4.

contribute significantly in the decision-making with regard to environment issues and to prevent further degradation of the environment.

5.

understand the fundamentals of water and treatments of waste water.

COURSE SYNOPSIS Environmental biology examines the role of organisms, in particular humans - as individuals or as members of society - interact with each other, and/or interact with their environment, from a biological (especially ecology) perspective. This course starts with a brief review of environmental problems and scientific principles, and an introduction to ecological principles and population dynamics. Then, it introduces learners to specific environmental issues such as land use planning and conservation. This course also highlights several environmental issues: air, water, noise and waste pollutions. The role of the Malaysian government, non-governmental organisations and international laws on the environment will also be discussed in this course. Finally the course presents some aspects of water pollution, and water treatments. The following points highlights the items covered in this course. Topic 1: This introductory topic emphasises the types of ecosystems present on earth. The concepts of ecosystem classification will also be discussed. The similarities and differences among the ecosystems will be discussed at length.

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COURSE GUIDE

Topic 2: This topic emphasizes the importance of land resources and conservation of these precious natural resources, as well as the various ways in which land is put to use. Urbanisation, urban land use and planning will also be discussed in this topic. Topic 3: This topic introduces various type of pollutions ă air, water, waste and noise pollution. The impact of these on ecosystems and on man will also be briefly discussed. Topic 4: This topic emphasises the importance of the ozone layer ă formation, causes of depletion and impact of the depletion. The greenhouse effect, climate change and rise of sea levels will also be discussed. Topic 5: This topic discusses the role of Malaysian government and nongovernmental organisations in managing the environment. International agreements and cooperation with regards to the environment will also be discussed. Topic 6: This topic discusses the basic chemistry of water pollution in different water bodies, and some aspects of water and sewage treatment.

EVALUATION METHOD Refer to the CAPL website http://capl.oum.edu.my for evaluation method for this course.

PREFACE 1. Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and gaseous state. 2. Water is a high priority concern in many countries including Malaysia. Water has also been accorded a high priority status in the global development needs. At the Johannesburg World Summit on Sustainable Development (WSSD) in 2002, all countries were required to develop integrated water resource management (IWRM) and water efficiency plans by 2005 in order to reverse the current trends of water resource depletion, and to improve integrated management of land, water and living resources within the ecosystem, while strengthening national capacities. 3. According to Global Water Partnership (GWP), IWRM is a process which promotes the coordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner, without compromising the sustainability of vital ecosystems. There have been other definitions of IWRM but the prime elements of IWRM are captured in the GWP version. 4. In view of the aforementioned needs and relevance, the Malaysian Water Partnership (MWP), Malaysian Capacity Building Network (MyCapNet), Department of Drainage and Irrigation (DID) and Humid Tropics Centre (HTC), Kuala Lumpur, have requested experts from various public universities together with Open University Malaysia to develop a Masters Programme. The Open University MalaysiaÊs platform for Open Distance Learning (ODL) is being used to disperse the programme to working learners in Malaysia and other countries. Learners of this programme will gain enough theoretical and hands-on experience that will enable them to be experts in all aspects of water resource management. 5. Although the entry requirement for this programme is a Bachelor of Science or Engineering or its equivalent, a few learners with Diploma and some years of experience in the areas related to water management were admitted. Progress of these learners is satisfactory. 6. Open Entry learnersÊ ability to follow all the courses in the Master Programme could be strengthened if they follow some undergraduate module related to environmental manager and water pollution cum treatment. The present course for the aspirants of the IWRM programme contains the basic needs required for their entry into the IWRM programme includes topics that may be treated as pre-requisite for the open entry learners. The module is written in a simplistic manner with 6 topics that are easy to understand.

T o p ic

1X Ecosystem

LEARNING OUTCOMES By the end of this topic, you should be able to:

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1.

Describe 4 different classifications of ecosystem;

2.

Identify and describe 4 types of terrestrial ecosystems;

3.

Identify and describe 4 types of aquatic ecosystems; and

4.

Compare the various types of terrestrial and aquatic ecosystems.

INTRODUCTION

Previous approach to biology was to study the range of different species, each in isolation, as examples of different levels of biological organization. However, it can only establish the structure and physiology of the individual organisms. The study of distribution and interaction among organisms and environment was very much lacking. Therefore, environmental biology examines the role of organisms, in particular humans ă as individuals or as members of society interact with each other, and/or interact with their environment. Environmental biology sets out to explain, amongst other things, the distribution patterns and their abundance of living things within the biosphere. In this topic, we shall describe and briefly characterize the major ecosystem types with an emphasis on the geological and biological differences that underlie the remarkable diversity of life on earth.

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1.1

TOPIC 1 ECOSYSTEM

CLASSIFICATION OF ECOSYSTEM SELF-CHECK 1.1

Ecologists from different background have developed different schemes for classifying life. Why is that so?

Carolus Linneaus introduced a classification system for organisms. The biological classification is used to show evolutionary distance and relationships between organisms. Can you recall the biological nomenclature hierarchy? In the learning of ecosystem, we also require a classification system. In classification of ecosystem, ecosystems are classified based on certain boundaries ă distribution of plants and animals. Plants and animals are distributed according to climate and geological events such as plate tectonics, continental drift, colonization, dispersion and speciation due to natural selection and neutral processes.

1.1.1

Biogeographical Regions

Biogeography is the study of distributions of organisms, both past and present. Alfred Wallace, a famous zoogeographer, divided the Earth into six biogeographical regions or realms based on the distribution of terrestrial animals. These realms are Palearctic, Nearctic, Neotropical, Ethiopian, Oriental, and Australian (Figure 1.1). Because some zoogeographers consider the Neotropical and Australian regions to be so different from the rest of the world, they group the four other regions together to make a more general classification: Neogea (Neotropical), Notogea (Australia) and Megagea (the rest of the world).

Figure 1.1: Biogeographical realms

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Each realm more or less embraces a major continental land mass and each is separated by oceans, mountain ranges, or deserts that prevent free dispersal of animals, and each possesses its own distinctive forms of life. Each region is further subdivided by secondary barriers such as vegetation types and topography. This classification provides an ecological foundation for the management of regional resources. Two regions, the Paleartic and the Nearctic, are closely related. In fact, the two are often considered as one, the Holarctic. Their area stretches from North America, the whole of Europe to the Himalayas, Northern Middle East and Africa. The regions are similar in climate and vegetation. They are alike in their faunal composition, and they share, particularly in the north, similar animals, such as wolf, hare, moose, caribou, etc. Animals found in South of the Nearticals, the Neotropical, which includes all of South America, part of Mexico and the West Indies are generally descendants of North American invaders, such as tapir and llama. The Australian is the most interesting and the strangest region, and certainly the most impoverished in vertebrate species. It includes Australia, Tasmania, New Guinea and smaller islands of the Malaysian Archipelago. Partly tropical and partly south temperate, the Australian is noted for its lack of a land connection with other regions, the poverty of freshwater fish, amphibians, and reptiles, the absence of placental mammals, and the dominance of marsupials. The marsupials have become diverse and have evolved ways of life similar to those of the placental mammals of other regions.

EXERCISE 1.1 What is the most famous example of a marsupials species?

1.1.2

Life Zones

Before the biome concept became generally accepted by environmental biologists, G. Hart Merriam (1884) was the first person to define precisely the relationship between climate and vegetation. He developed his life zone system after observing the sharp zonation of vegetation on the San Francisco Mountain in Arizona. Although not widely used today, his life zones are reflected in the temperature hardiness zones mapped and widely used in horticultural and planting guides. On the other hand, Holdridge life zone system (Figure 1.2) is a more sophisticated approach to the relationship of vegetation patterns to climate. It

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divides the vegetation of the world into zones defined by mean annual precipitation and mean annual biotemperature. Biotemperature is defined as the mean of unit-period temperatures with the substitution of zero for all unit period below 0ÀC and above 30ÀC. The Holdridge system involves three levels of classification: Ć

climatically defined life zones;

Ć

associations ă subdivisions of life zones based on local environmental conditions; and

Ć

further local subdivisions based on actual cover or land use.

The life zones are determined by a gradient of mean annual biotemperatures with latitude and altitude, the ratio of potential evapotranspiration to animal and annual precipitation, and total annual precipitation. The Holdridge life zone classification differs from many other ecosystem or biome classifications in that is explicitly defines a relationship between climate and vegetation/ecosystem distribution.

Figure 1.2: The life zone classification (Holdridge 1967) is determined from biotemperature and annual mean precipitation. Potential evapotranspiration is a linear function of biotemperature. The hexagons delimit the different life zones

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Note: Dependence of animals on plants means that a classification of ecosystems based on vegetation is often accurate enough to allow differentiation of animal inhabitants as well. The combination of vegetation and climate results in a near perfect classification of ecosystems. Thus, the concept of biogeographical regions is mostly utilized in evolution and taxonomy where lie its roots than in ecology.

1.1.3

Biomes

For many years ecologists have related world plant formations to climatic patterns. European ecologists, like the early plant geographers, consider the broad vegetation patterns of the world as plant formations. Ecologist F. E. Clements and V. E. Shelford (1939) introduced the concept of the biomes as classification of world vegetation patterns. They considered the broad plant formations and their associated animal life as biotic units. They called these biotic units biomes, each of which is characterized by a uniform life form of vegetation, such as grassland or coniferous forest. Boundaries between biomes, of course, are broad and indistinct as one vegetation type blends into another. By including both plants and animals as a total unit that evolved together, the biomes permit recognition of the close relationship among all living things. There are at least nine major terrestrial biomes (Figure 1.3): tundra, taiga, temperate forest, tropical rainforest savanna, desert, etc which we will discuss at length in section 1.2.

Figure 1.3: Pattern of biome distribution (Mader, 1998)

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1.1.4

TOPIC 1 ECOSYSTEM

Ecoregions

Ecoregions are major ecosystems that result from predictable patterns of climate as influenced by latitude, global position, and altitude. It is developed by R.W. Bailey (1976, 1995, 1998) which is a recent approach to the classification and mapping of the biotic world. It is a scheme that refines the biome-types into hierarchies. It classifies terrestrial and ocean ecosystems on the basis of large geographical areas or domains. There are four domains which are polar, humid temperate, humid tropical and dry. It was later on further subdivided into 14 divisions. Subdivisions of terrestrial ecosystems are based on the interaction of climate, soil, continental position, and topography. Oceanic ecoregions are based on the interaction of microclimate, large-scale ocean currents, and salinity.

1.2

TERRESTRIAL ECOSYSTEM

A quarter of the earthÊs surface is covered with dry land. The variety of climates, the diversity of soils and the heterogeneity of landscape govern the diversity of communities and ecosystems, which unlike, aquatic ecosystem has water as their medium. A terrestrial ecosystem is a three-phase system composed of the atmosphere and climate, the soil and the biotic community. The atmosphere is the source of oxygen for animals and carbon dioxide for plants. Rainfall or water is vital to all organisms. Temperatures on terrestrial ecosystem are controlled by the absorption of heat by soil, rocks and vegetation. Soils provide nutrients and support to plants. It is also the site of the entire detritus food chain, and thus is central to the biogeochemical cycling of nutrient materials. Different types of soils have different properties that affect the availability of nutrients to plants, so that the productivity of terrestrial ecosystems is closely tied to the characteristics of their soils. Finally, the diversity and the degree of influence of interspecific interactions (competition between members of different species populations in a community) are major factors in creating the habitat for other organisms. For example, the habitat of a flower on a forest floor is as much a function of the forest trees as it is a function of the soils and climate, since the trees determine how much light reaches the flower. These biological interactions may have negative, neutral or even positive influences on interacting populations which leave a permanent mark on the entire terrestrial ecosystem. In addition, ecological succession (a directional, cumulative change in the species that occupy a given area, through time) in a terrestrial community is driven almost entirely by the organisms within the ecosystem. For example, open ground might be colonized by sun

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tolerant plants. However, as they grow they produce more shade, which makes the habitat less suitable for them and more suitable for shade tolerant species. The variation in terrestrial ecosystems is infinite, and there are seldom, if ever, clear- cut boundaries between them. But many species typically occur together, and we can speak meaningfully of types of ecosystems, based on the similarity of their composition or structure. They tend to be distributed in areas of similar geographic characteristics. They have practical as well as descriptive significance, since they provide a framework within which to interpret differences or similarities between communities. We can also compare a community presently occupying an area that has been altered by human manipulation with the community that would have been present had people not interfered with the natural ecosystem.

EXERCISE 1.2 Name the three components of a terrestrial ecosystem.

1.2.1

Grasslands and Savannas

Grasslands Over one quarter of the EarthÊs surface is covered by grasslands. Grasslands are found on every continent except Antarctica, and make up most of Africa and Asia. They are called prairies in North America, stepes in the Eurasin region, pampas in Argentina, puszta in Hungary and veldt in South Africa. The vegetation is dominated by grasses, legumes and composites. Grasslands develop for a variety of reasons. Generally, any combination of circumstances that restrict germination and/or growth of wood plants results in the formation of a grassland. These include rainfall, soil type, seasonality, fires, grazers and general stability. Grasslands develop where there isnÊt enough rain for forest but too much rain for deserts, with rainfall ranging from 250mm to 800mm per annum. Grasslands are filled with grass. Grass is special because it grows underneath the ground. During cold periods, the grass can stay dormant until it warms up. In the regions with high evapotranspiration, grasses height can rise to about 3.5 metres. Animal life is dominated by grazing and burrowing species.

Savanna Savannas (Figure 1.4) cover much of Central and Southern Africa, Western India and Northen Australia, Northern Brazil (called cerrados), Columbia and Venezuala (called Ilanos). The major stratum of the Savanna ecosystem is trees

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that grow far apart and with grasses and shrubs between them. Some Savanna is arid, with scattered thorny trees. Most of this region has arisen as a result of the climate but some has evolved from the destruction of rain forests by man. The Savannas are dominated by animal grazers and animal browsers. Trees available here are deeply rooted. Usually, grasses obtain nutrients from decomposing of tree leaves. The decomposition process is rapid in this area due to the warm climate and the soil houses abundant decomposer organisms. However, in recent years, these trees are used for fuel and this drastically decreases the soil productivity.

Figure 1.4: General view of the savanna at Calabozo of Venezuala (San Jose and Montes, 1998)

1.2.2

Shrublands and Deserts

Shrublands Shrublands cover large portions of the arid and semiarid world. It is characterised by having plants with woody and persistent stem, but no central trunk and a height of up to 4.5 or 6 m. The Mediterranean-typed shrublands lie between 32À and 40À north of the equator (areas with Mediterranean climate); the semiarid regions of western North America, the regions bordering the Mediterranean Sea, central Chile, the Cape, region of South Africa, and Southwestern and southern Australia. These areas have similar plant communities of broadleaf evergreen shrubs and dwarf trees known as sclerophyll (scleros, „hard‰; phyll, „leaf‰). It is also dominated by shrubs averaging ó to 1 m in height.

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Due to the prolonged summer drought, shrubs have thick and waxy leaves to prevent water loss. Surprisingly, a few epiphytes, including the Spanish moss (Tillandsia recurvata) and some orchids may be present, but grasses are very uncommon. The entire herbaceous layer, in fact, may be poorly developed. Species diversity of both plants and animals is very low. Soils are poorly developed, quite dry through exposure to the sun, and calcified. Fire is an important part of this ecosystem, where human activities have suppressed cyclical fires. Fire suppression has resulted in more fuel accumulated such that fires are often larger and more destructive when they occur.

Deserts Deserts are defined by geographers as areas where evaporation exceeds rainfall. These ecosystems are either barren or with scanty vegetation consisting mainly of thorny bushes. Most deserts of the world receive some rain every year. In places which do not receive rainfalls for several years, the ground may appear absolutely barren; however, there is a light green covering of annuals just after the rains, on the rare occasions when they occur. Deserts are classified as warm and temperate. The hot deserts are the Sahara in northern Africa and Arabia, Klahari in southern Africa, and Thar in India. The deserts of Mexico, Atacama in South America, and the Australian deserts (central and western Australia) are also hot deserts. The deserts of Iran and Turkey, the Gobi desert of Mongolia and some deserts of Argentina are classified as temperature or cold. Desert is characterised by scanty vegetation. Cacti and small trees are found scattered. It has less than 25mm rainfall per year with its high temperatures and evaporative water loss at day time and, cold temperatures at nights. Plant reproduction may be a rare event. Desert plants and animals display numerous water conserving adaptations. Large animals are very uncommon, although the mule deer and some species of gazelle may be found in small number in shrub areas. Small rodents are the most common mammals, along with the coyote and small foxes, but most of the herbivores are insects. Because of this, the numbers of small insectivorous lizards are higher in the desert than in other biomes. As in other open areas, running, digging, and jumping adaptations are widespread among all animals.

1.2.3

Tundra and Taiga

Tundra Encircling the northern pole of Earth is a region of cold, often desert-like conditions, the Artic tundra (Figure 1.5). The word comes from the Finnish tunturia, meaning „a treeless plain‰. At lower latitudes similar landscapes, the

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alpine tundra, occur at the peaks of tall mountains. Artic tundra is treeless and barren but for some grasses, sedges, lichens, rocks and water may be present. The ground surface is spongy, uneven or hummocky as a result of freezing and thawing. The land is poorly drained. At a depth of a few inches, the soil is in permafrost (alternate freezing and thawing and the presence of a permanent frozen layer in the ground), which limits the depth to which plant roots can reach. Vegetation structure is simple. The characteristic artic tundra plant is reindeer moss (Cladonia). The net primary productivity is extremely low. consumers are dipteran flies (black flies), mosquitoes, other insects, migratory birds in summer. The caribou, musk ox, artic hare, artic fox lemming are important mammalian consumers.

the The and and

In the Antarctic, well developed tundra is mostly lacking because of a small land area and deep ice sheets but the land is better drained, and permafrost is absent. Both Artic or alpine, tundra is characterised by low temperatures, low precipitation (cold air carries little moisture), and a short growing season ranging from 50 to 60 days in the high Artic tundra and to 180 days in low-altitude alpine tundra.

Figure 1.5: Alaska tundra in the summer (Stern, 2000)

Taiga Taiga (Russian literally for „land of little sticks‰) or Boreal Forests is a belt of coniferous (cone bearing gymnosperms) forest encompassing the high latitudes of the Northern Hemisphere which covers about 11% of EarthÊs terrestrial

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surface. Winter, the dominant season, is severe and the small amount of precipitation the region receives comes in the three warm months. Because of the cold that inhibits evaporation, the region is moist all year. The needle-leaf evergreens are adapted to cold winters, and they respond rapidly to the short summer. Four major vegetation zones make up the taiga: Ć

the forest-tundra ecotone with open stands of stunted spruce, lichens, and moss;

Ć

the open boreal woodlands of stands of lichings and black spruce;

Ć

the main boreal forest with continuous stands of spruce and pines broken by poplar and birch on disturbed areas, and

Ć

the boreal-mixed forest ecotone where the boreal forest grades into the mixed forest of sourthern Canada and the northern United States.

1.2.4

Forest (Temperate, Tropical and Mangrove)

Forests are known to house a variety of floras and faunas. It provides shelter, foods and protection to the floras and faunas. Many trees are 20-30 metres high when mature and others very much higher; many survive for several hundred of years.

Temperate Forest Temperate forests do not necessarily occur in temperate environment. They occupy topographic positions that range from low-lying lands to mountaintops, and environmental conditions that range from warm and semiarid to cold and wet. Temperate forest consists of coniferous, deciduous, or mixed stands. Coniferous forests are usually montane forests on mountain slopes. High mountains extend vertically through more than one climatic zone and hence the vegetation is distinctly marked. In the northern hemisphere, these vegetation zones are usually dominated by cone bearing trees, such as pines, spruce, firs, hemlock, etc. In North America, the usual climatic gradient on any high mountain range is from warm and relatively dry near the base to colder, snowier, wetter and windier higher up. On very high mountains, the crest may be too cold and windy to bear trees. Montane coniferous forests are characteristic of North American mountains. It is believed that temperate deciduous forests once covered large areas of Europe and China, parts of South America and the middle American highlands, and eastern North America. Glaciers and the droughts of the Pleistocene era divided it into three main parts, namely eastern North America, Western Europe, and

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eastern Asia. These forests are dominated by birch, beech, oaks and ash trees. The net primary productivity is about 3 to 5 tonnes per acre per year. Low temperature, the lack or excess of certain minerals, and in some parts, arid conditions, are the limiting factors. Flowering is confined to the short spring season. Examples of important consumers are the deer, fox, bear, bobcat, and wild turkey. The mixed stands are usually known as the temperate evergreen forests. The subtropical areas of the world have mixed forest of broadleaf evergreen and coniferous trees. Such forest includes the eucalyptus of Australia, paramo forests and anacardia gallery forests of South America and New Caledonia, and false beech (Northofagus spp) forests in Patagonia.

Tropical Forest Tropical forests belong to the Rain Forest of the Humid Tropical Domain. Tropical forests experience a steady year-round temperature of about 23ÀC and a wide variation in rainfall and climatic conditions that are reflected in a diversity of vegetation patterns. In a very broad way, tropical forests can be classified as tropical rain forest, montane rain forest, tropical seasonal forest, and tropical dry forest. Within these broad groups is a diversity of vegetation types unequalled anywhere else in the world. Tropical rainforests are located around the equator where temperatures stay near 26ÀC years round. Rainforest receive 400-1000 cm of rain each year. The largest rainforests are in Brazil (South America), Zaire (Africa) and Indonesia (South East Asia). Other tropical rainforest are in Hawaii and the islands of the Pacific and Caribbean. With its characteristic heavy precipitation (rain), it is abundant with a diverse species of wildlife and vegetation. Even though rainforests cover less than 2% of the EarthÊs surface, they are home to some 50 to 70% of all life forms on our planet. Tree species number in the thousands. A 10 square kilometre area of tropical rain forest may contain 1500 species of flowering plants and up to 750 species of trees. The richest is the lowland tropical forest of Peninsular Malaysia, which contains some 7900 species. The dominant family, the Dipterocarpaceae, comprises 9 genera and 155 species, of which 27 are endemic. Rainforests are the most productive and most complex ecosystems on Earth. Vertical stratification are well developed (Figure 1.6). Emergents are the tallest trees and are usually over 50 metres tall. The kapok tree is an example of an emergent. The sea of leaves blocking out the sun from the lower layers is called the canopy. The canopy houses a variety of faunas such as birds, snakes and monkeys. Liannas (vines) climb to the canopy in search of sunlight. The lower canopy mainly contains bare tree trunks and lianas. The shrub layer has the

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densest plant growth. It contains shrubs and ferns and other plants needing less light. Saplings of emergent and canopy trees can also be found here. The forest floor is usually dark and damp. It contains layers of decomposing organic matters. This decomposes rapidly (within 6 weeks) to form thin humus, rich in nutrients. Deforestation (cutting down trees) is a major problem caused by humans in the tropical rainforest. Most of the rainforests has been degraded or eliminated by lumbering, clearing for plantations, settlements, and agriculture.

SELF-CHECK 1.2 In your opinion, what can we as human do to help save the rainforest?

Figure 1.6: Layers in a tropical rainforest

Mangrove Forest Mangrove forests are ecosystems restricted to the tropics that at confluence (meeting point) of the marine and terrestrial environments characterised by saline or brackish waters and are dominated by mangrove trees. Such areas include sea shores, intertidal zones, river-mouths (estuaries and deltas) are inland saline wetlands. The classification of mangroves is unclear. Many ecologists regard them (wetlands) as aquatic (or semi- aquatic) ecosystems, but in

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economic and conservation terms, they are often regarded as terrestrial (forest) ecosystems (see Figure 1.7). Mangrove trees have specific characteristics such as tough root systems, special bark and leaf structures and other unique adaptations to enable them to survive in their habitatÊs harsh conditions. The substratum is soft, silty and shallow, coupled with the endless ebb and flow of water providing very little support for most mangrove plants which have aerial or prop roots (known as pneumatophores, or respiratory roots) and buttressed trunks. A mature and extensive mangrove forest often has zones, where the types of plants changes as you move away from the sea. This has to do with the water and salinity level. Plants like Avicennia and Sonneratia do well in sandy areas, Rhizophora copes with better soft humus and rich mud while Bruquiera favours stiff clay containing little organic matter. The major mangrove species found here are obligate inhabitants of the mangrove ecosystem and not found elsewhere in the world. These forests are essential to provide coastlines protection and provide resources for coastal communities.

Figure 1.7: Mangrove Forest of Bako, Kuching

SELF-CHECK 1.3 The plants and animals found in mangrove forest are not found in other ecosystems. Why?

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AQUATIC ECOSYSTEM

About ¾ of earth surface is covered by aquatic ecosystems, with most of this being oceans. It is classified into two broad categories defined by salinity ă freshwater and marine ecosystems. Freshwater ecosystems include lakes and ponds (lentic ecosystems), streams (lotic ecosystems), and, marshes and peatswamps (wetlands), whereas, marine ecosystems include oceans. Aquatic ecosystem is a complex ecosystem. The aquatic ecosystem is mainly governed by the amount of light (without interference of human). Aquatic organisms require light for production of food (photosynthesis) and heat.

1.3.1

Freshwater

Lentic Ecosystem Lentic ecosystems contain water that is not flowing and are a closed system with lower rates of nutrients loss. They cover approximately 2.25 million square kilometres of the world. Do you know that the largest inland body of water is the Caspian Sea (436,000 square kilometres) while the deepest lake on the planet, Lake Baikal in Russia (maximum depth 1620 meters) which contains about 20% of the world freshwater. Lakes are formed by glacial activity, earthquakes or when there are some obstacles in free flowing moving water which will be turned into basins. Lakes and ponds have well- defined boundaries where, within each boundary, the environmental conditions vary from one pond or lake to another. The variations in oxygen content, temperature and light strongly influence the distribution and adaptations of life in ponds and lakes. In addition to the zonation in a lakeÊs physical parameters, there is zonation in terms of the organisms that inhabit the lake. Lakes and ponds can be said to have the following zones (Figure 1.8): Ć

Littoral zone: shallow water about the edges where aquatic life is the richest and most abundant. Dominating these areas is emergent vegetation, plants whose roots are anchored in the bottom mud, whose lower stems are immersed in water, and whose uppers stems and leaves stand above water.

Ć

Limnetic zone: open water which extends to the depth of light penetration where minute plant (phytoplankton) and animal organisms (zooplankton) live.

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Ć

Profundal zones: this zone lies below limnetic zone and depends not only on the supply of energy and nutrients from above but also the temperature and availability of oxygen.

Ć

Benthic zones: zone of decomposition. This zone is the region of great biological activity. Lake and ponds show a sharp drop in oxygen just above the bottom. Low levels of aeration, the dominant organisms are anaerobic bacteria.

Figure 1.8: Lentic model

Lake systems can be broadly classified as oligotrophic or eutrophic on the basis of their nutrient contents and rates of photosynthesis. Ć

Oligotrophic systems: Oligotrophic lakes have a low surface to volume ratio, water that is clear and appears blue to blue-green in the sunlight. Nutrient content of the water is low, although nitrogen may be abundant, phosphorus is highly limited.

Ć

Eutrophic systems: A typical eutrophic lake has a high surface to volume ratio; i.e. the surface area is large relative to depth, it has an abundance of nutrients, especially nitrogen and phosphorous, that stimulates heavy growth of algae and other aquatic plants.

Runoffs from terrestrial environments carrying silt and nutrients in suspension solution respectively, and also due to human activities (logging, road construction) contribute to the nutrient enrichment of the lentic ecosystems which are known as eutrophication.

Lotic Ecosystem Flowing water is the dominant feature of lotic ecosystems (Figure 1.9) from brooks to rivers. Physical factors play a crucial role in the ecology of flowing water. Among the most important of these is water current. The rate of flow is determined by the stage of the streambed, the volume of water in the stream, and the nature of the resistance downstream. The volume of water in a stream or

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river can change dramatically over a very short period of time. Storms or rapid snowmelt can greatly increase the rate of flow. If a stream encounters resistance, as it does when it enters a lake, flow decreases near the point of resistance. The flow rate of water current is important because it determines the rate at which materials such as nutrients are flushed out of the systems and it determines the type of bottom (sandy, gravel, or rock) which in turn, determines the kinds of plants and animals that can live there. Nutrients such as nitrogen and phosphorous are limiting because they are flushed out in solution. The major input of carbon is in the form of detritus from nearby terrestrial ecosystems.

Figure 1.9: Flowing water model

Generally streams can be classified into fast-water streams and slow-flowing streams. Fast water streams (50cm/sec) are a series of two essentially different but interrelated habitats where turbulent riffle triggers primary production and the quiet pool is the place where decomposition takes place. While the slowflowing streams allow silt and decaying organic matter to accumulate on the bottom and detritus from upstream is the main source of energy. It supports the growth of emergent vegetation and plankton.

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Wetland At the interface between freshwater and terrestrial systems are a number of semiaquatic habitats collectively termed wetlands. Wetlands are areas that range along a gradient from permanently flooded to periodically saturated soil and support hydrophytic (water-loving) vegetation at some time during the growing season. Generally, wetlands are lands where saturation with water is the dominant factor determining the nature of soil development and the types of plant and animal communities living in the soil and on its surface. Wetlands vary widely because of regional and local differences in soils, topography, climate, hydrology, water chemistry, vegetation, and other factors including human disturbance. Due to the wide variety of wetlands (from fresh water to salt) classifying them for management and conservation has presented problems. Wetlands most commonly develop in shallow basins raging from upland topographic depressions to filled-in lakes and ponds, known as basin wetlands; along shallow and periodically flooded banks of rivers and streams, known as reverine wetlands and along the coastal areas of larger lakes and oceans, known as fringe wetlands (mangrove communities). Wetlands may have deep or shallow water, or occupy soils hat are water-saturated to various degrees. Wetlands dominated by emergent herbaceous vegetation are marshes. Supporting reeds, sedges, grasses, and cattails, marshes are essentially wet grasslands. Wetlands dominated by woody vegetation, or forested wetlands, are commonly called swamps. Wetlands have important filtering capabilites for intercepting surface ă water runoff from higher dry land before the runoff reaches open water. As the runoff water passes through the wetlands, they retain excess nutrients and some pollutants, and reduce sediment that would clog waterways and affect fish and amphibian egg development.

1.3.2

Marine

Ocean The worldÊs oceans cover nearly three-fourths of the surface of the planet, and constitute one of the largest potential habitats for plants and animals. The oceanic environment is very different from that of inland waters, the major difference being the chemical composition of water. Sea water is a very dilute solution of many mineral substances derived from the earthÊs crust. The sea consists of the following: Ć

Mineral content is 35 parts per thousand of sea water, or 3.5% minerals;

Ć

Sodium chloride is about 10.5 parts per thousand of sea water;

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Ć

Sodium, potassium, magnesium, calcium sulphur, boron, barium, strontium, silicon, etc constitute the minerals of sea water;

Ć

Chlorine is about 19 parts per thousand; and

Ć

Salinity of ocean water varies with depth.

The living organisms in the sea are classified into plankton, nekton and benthos. Hansen (1937) coined the term plankton to apply to minute floating organisms, usually found in surface waters, whose movement depends upon the direction of water currents. Nektons are larger curstacea, molluscs, fish, turtles, sea birds, and mammals of the sea. Benthos are the bottom dwellers and consists of sessile forms, such as limpets, chitons, mussels, oysters, sponges, corals, hydroids, anemones, some worms, bryozoans, crabs, lobsters, some echinoderms, flat fish, etc. They also include burrowing (infauna) and creeping (epifauna) forms. The oceans can be divided into pelagic, benthic and intertidal (Figure 1.10). The pelagic zone includes the open sea where water is nutrient poor and productivity is comparable to that of the terrestrial deserts. The primary producers of this zone are the diatoms, unicellular and multicellular algae, dinoflagellates, etc which form the phytoplankton. In the oceanic pelagic zone the photic zone may extend up to 250 feet, beyond which is the aphotic, permanently dark zone. The benthic zone is cold, dark and devoid of producer organisms. The organisms living here exhibit unique adaptations due to enormous water pressure, dark conditions, detritus and carnivorous food chains. Organisms found here are either black or red in colour (under certain circumstances such as chemical and hot water vents with chemosynthetic and thermosynthetic bacteria) and have very sensitive eyes, or receptors. Some of them exhibit bioluminescence. In some the body becomes flat and the eyes move to one side. Benthic organisms are either detritus feeders or carnivores. A gently sloping continental shelf extends from the coast line to about 160 km. At the intertidal zone, organisms are exposed to sunlight and air.

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Figure 1.10: Ocean model

A coral reef is composed of thin plates or layers of calcium carbonate secreted over thousands of years by billions of tiny soft bodied animals called coral polyps. It takes years for some corals to grow an inch and they range in size from a pinhead to a foot in length. Each polyp excretes calcareous exo-skeleton and lives in a symbiotic relationship with host algae, zooxanthellae, that gives the coral its colour. Millions of polyps grow on top of the limestone remains of former colonies to create the massive reefs. These tiny animals form the only natural formation visible from outer space. Coral reefs are the most biologically diverse marine ecosystems on earth, rivalled only by the tropical rainforest on land. Corals grow over geologic time and have been in existence about 200 million years ago. Corals reached their current level of diversity 50 million years ago. The delicately balanced marine environment of the coral reef relies on the interaction of hard and soft corals, sponges, anemones, snails, rays, crabs, lobster, turtles, dolphins and other sea life. Coral reef are

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divided into 3 kinds comprising fringing reefs (grow seaward from the rocky shores of islands and continents), barrier reefs (parallel shorelines of continents and islands and are separated from land by shallow lagoons) and atolls (horseshoe-shaped rings of coral reefs and island surrounding a lagoon). Coral reefs occupy less than 1% of the marine environment, but they are home to more than 25% of all known fish species. Because the majority of coral reefs are located in regions known for extreme poverty and high population growth rates, they are particularly vulnerable to degradation. Southeast AsiaÊs reefs are the richest in term of variety of species, but over 80% of them are threatened, primarily from coastal development, tourism and fishing-related activities.

The classification of life is somewhat arbitrary due the similarities shared by different ecosystems. However, the relationships among climate, geography, and vegetation for each of the ecosystem could be well defined.

Biome Biosphere Desert Ecoregion Ecosystem

Habitat Life Zone Taiga Tundra

Multiple Choice Questions 1.

Which of the following is the most complex ecosystem? (a) coral reef (b) desert (c) tropical rain forests (d) tundra

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2.

In a region with moderate to high precipitation, limited droughts and seasonal temperature, you are most likely to find: (a) forest (b) grassland (c) desert (d) wetland

3.

All species on Earth together with their environment collectively comprise the (a) lithosphere (b) geosphere (c) hydrosphere (d) biosphere

4.

The study of how organisms interact with each other and their environment is called (a) etiology (b) biology (c) environmental biology (d) environmental science

5.

An ecosystem is (a) a grouping of plants, animals, and microbes occupying an explicit unit of space and interacting with each other and with their environment (b) a grouping of producers, consumers, and detritus feeders in the natural landscape (c) the same as the biosphere (d) the same as the lithosphere

6.

A biome strongly influenced by fire is a (a) shrubland (b) deciduous forest (c) tundra (d) desert

7.

When considering the distribution of modern day coniferous forests, the primary controlling factor is (a) cold temperatures (b) droughts (c) latitude (d) sunlight

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8.

A lake rich in nutrients and species is classified as (a) dystrophic (b) oligotrophic (c) eutrophic (d) ecotrophic

9.

The marine ecosystem is divided into two large categories based on (a) water level (b) salinity (c) nutrient content (d) fish species

10.

Which of the following is the zone of decomposition in an aquatic ecosystem? (a) Benthic (b) Profundal (c) Limnetic (d) Littoral

11.

In which ecosystem is there the greatest rate of litter returning to the soil? (a) Alpine vegetation (b) Tropical rainforest (c) Temperate grassland (d) Arctic tundra

Structured Questions 1.

Constrast between lentic and lotic ecosystems.

(5 marks)

2.

What is a mangrove forest?Explain in details by relating it with the vegetation available there. (5 marks)

3.

Define the following: (i)

Oligotrophy

(2 marks)

(ii)

Eutrophy

(2 marks)

4.

Vertical stratification are well developed in tropical rainforest. Name and describe all the five layers. (10 marks)

5.

Name the six biogeographical regions.

(6 marks)

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TOPIC 1 ECOSYSTEM

List the three components of a terrestrial ecosystem

(3 marks)

(i) (ii) (iii)

Brewer, R. (1994). The science of ecology. (2nd ed.). USA: Harcourt Brace College Publishers. Dash, M. C. (1993). Fundamentals of ecology. New Delhi: Tata McGraw Hill. Krohne, D.T. (2001). General ecology. (2nd edition). USA: Brooks/Cole, Thomson Learning Inc. San Jose, J., & R. A. Montes. (1998). NPP grassland: Calabozo, Venezuela, 19691987. Data set. http://www.daac.ornl.gov. Tennessee. Oak Ridge National Laboratory. Smith, R.L. & Smith, T.M. (2001). Ecology and field biology. (6th ed.). USA: Benjamin Cummings. Smith, R.L. (1992). Elements of ecology. USA: Harper-Collin Publishers. Sylvia S. Mader. (1998). Biology. (6th ed.). USA: McGraw Hill.

Topic X Land Use and

2

Conservation

LEARNING OUTCOMES By the end of this topic, you should be able to:

X

1.

Identify the different types of land resources and their importance;

2.

State the uses and functions of natural areas;

3.

Describe how urban area develops and the causes of urban growth; and

4.

Describe land use management in urban areas.

INTRODUCTION

EarthÊs total land area is about 144.8 million kmñ, or about 29% of the surface of the globe. Four major uses land are for rangelands, agriculture, wilderness and forests, and wetlands. These lands provide many essential environmental services. However, human activities sometimes degrade land to the point where it cannot provide essential environmental services, such as controlling soil erosion, protecting water quality, regulating water flow in rivers and streams, and providing wildlife habitat. Two extremely serious land use problems caused by the increase of human populations are removal of forest, or deforestation, and expansion of deserts, or desertification. Since the beginning of the Industrial Revolution some three hundred years ago, much of the worldÊs population has moved from rural to urban areas. This urbanization of human populations, combined with rapid population growth, affects almost everything about our lives, including our environmental problems, e.g., water pollution, air pollution, and etc. Therefore, urban land-use planning practises have become as important as rural land use planning.

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LAND USE AND CONSERVATION

In this topic, you will learn more about the importance of land resources and conservation, as well as the various ways in which land is put to use. Urbanization, urban land use and planning also will be discussed in this topic.

2.1

LAND RESOURCES AND CONSERVATION

Land has multiple uses and benefits. Four major uses of land are rangelands, agriculture, wilderness and forests, and wetlands. These lands provide many essential environmental services such as controlling soil erosion, protecting water quality, regulating water flow in rivers and streams, and providing wildlife habitat. But human activities sometimes degrade land to the point where it cannot provide essential environmental services.

2.1.1

Agricultural Lands

Agricultural activities have permitted the earth to support increasing numbers in human populations over the years. The main threat to this increase is a shortage of land that can be used to grow crops. Only about 15% of the earthÊs surface can be farmed because the rest is made up of ocean, permanent ice, steep slopes, and deserts. About half of this farmland is already farmed. Fresh land is brought into crop production every year, most of it by converting forest land into farmland. Every year an almost equal area is also lost to production when it is built on, or when its soil becomes so degraded that plants can no longer grow on it. Basically, agricultural land can be divided into arable land upon which crops can be grown, and rangeland, land better suited to animal grazing. The majority of crops grow healthy and rapidly in fertile soils. Fertile soils are composed of rock particles, humus (decaying organic matter), living organism, water and air. Top soil is the upper surface of a soil profile. Top soil is usually no deeper than 8 inches. The top soil contains high humus, minerals, composted materials and macroorganisms. The subsoil is the layer below the top soil. Subsoil may consist of decomposed or partially decomposed biomass and partially weathered minerals and rocks. Under subsoil lies bedrock, solid rock that may break down to form soil over long periods of time (Figure 2.1). The mineral nutrients plants need come from rock particles in the soil. Soils are classified by the average size of their particles. The finest particles give rise to clay soils, larger particles to silt, and still larger particles to sand. The size of soil particles affects a soilÊs capacity to hold water. The best soil for plant growth contains a mixture of particle sizes. Clay particles hold adequate water; its larger particles assist drainage, and allow air to penetrate the soil.

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Figure 2.1: Soil structure

The most fertile soils contain a great deal of organic matter called humus such as dead plants and animals, animal excrement, and microorganisms. This humus holds soil water and keeps the soil loose, allowing plant roots to grow through it easily. Organic matter on the soil surface insulates the soil from the heat of the sun and reduces water loss by evaporation. Many soil organisms are decomposers that release nutrients from organic matter. Some bacteria can also fix nitrogen from the air into nitrates that plants can use (Figure 2.2). These nitrogen fixing bacteria grow in nodules on the roots of legumes such as peas, beans, and acacias. Planting legumes adds nitrogen to the soil.

Figure 2.2: How plants get nitrogen from the soil

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LAND USE AND CONSERVATION

Every year, farming degrades large areas of land to the point where the soil is so poor or so completely eroded and compacted that it can no longer be used as arable land. For these reasons, soil is often treated to adjust its chemistry and structure for the intended crop. Inorganic fertilizers are added to soil to increase the nutrients available for plants. Organic fertilizers such as manure have the advantages of improving the soil structure and alter its pH as well as providing nutrients to the degraded soil. Beside these, lime (calcium carbonate) is also been added to clay soils to increase the particle size. Tilling the soil, that is turning soil over before planting seeds and turning over the soil around plants as they grow can reduce or reverse soil compaction by heavy agricultural machinery. Tilling has two major purposes: 1) it mixes up the nutrients and loosens soil particles, and 2) it gives the crop plants a competitive advantage over weeds, which are deliberately disturbed to damage their roots.

EXERCISE 2.1 1.

List the five components of soil.

2.

State the two major purposes of tilling the soil.

2.1.2

Rangelands

Rangelands are grasslands, in both temperate and tropical climates, that serve as important areas of food production for humans by providing fodder for domestic animals such as cattle, sheep, and goats. The predominant vegetation of rangelands are grasses, forbs (small herbaceous plants other than grasses), and shrubs. Grasses, have a fibrous root system, in which many roots form a diffuse network in the soil to anchor the plant. Plants with fibrous roots hold the soil in place quite well, thereby reducing soil erosion. Leaves of grass grow from the base, not the tip. Thus, as long as only its upper part is eaten by animals and its lower part remains, the roots can still continue to develop and grow to its original size (Figure 2.3). Therefore, rangeland grass is a renewable resource that can be grazed again and again. Rangeland has a number of important ecological functions. It provides forage for large numbers of wild herbivores and essential habitats for a variety of wild plant and animal species. It also acts as crucial water sheds that help replenish surface and groundwater resources by absorbing and slowly releasing rainwater.

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Rangeland is a valuable resource for recreation such as hiking, camping, and hunting.

Figure 2.3: Grasses can be grazed without harm as long as the metabolic reserve is left intact

Overgrazing occurs when too many animals graze for too long and exceed the carrying capacity of grassland. The carrying capacity of a rangeland is the maximum number of animals the rangeland plants can sustain. Usually the first symptom of overgrazing is a sharp decline in the most palatable herbs and grasses. Heavy overgrazing compacts the soil, which diminishes its capacity to hold water and to regenerate itself. Most of the worldÊs rangelands lie in semiarid areas that have natural extended periods of drought. Under normal conditions, native grasses can survive a severe drought: the aboveground portion of the plant dies back, but underground the extensive root system remains alive and holds the soil in place. When the rains return, the roots send forth new above ground growth. When overgrazing occurs in combination with an extended period of drought, however, once-fertile rangeland can turn to deserts. The lack of plant cover due to overgrazing allows winds to erode the soil. Even when the rains return, the land is so degraded that it cannot recover. Water erosion removes the little bit of remaining topsoil, and the sand that is left behind forms dunes. This process, which converts rangeland to desert, is called desertification. It ruins economically valuable land, forces out wildlife, and threatens endangered species.

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TOPIC 2

LAND USE AND CONSERVATION

Wilderness and Forests SELF-CHECK 2.1

Why do we need to preserve wilderness?

Wilderness areas provide mostly undisturbed habitats for wild plants and animals. They are theoretically renewable but, once destroyed, are replaced only slowly. Wilderness are areas that have not been greatly disturbed by human activities and that humans visit but do not inhabit. According to wilderness supporters, we need these places where we can experience the beauty of nature and observe natural biological diversity, where we can enhance our mental and physical health by getting away from noise, stress, and avoid large numbers of people. Currently, about 6% of the worldÊs land area is either strictly or partially protected in more than 20,000 nature reserves, parks, wildlife refuges, and other areas around the globe. North and Central America have set aside the highest percentage of land in parks and reserves (almost 12%), followed by Oceania (10%). The countries of the former Soviet Union have set aside the least, only 1.1%. In United States, the Wilderness Act (1964) has authorised the government to set aside public wilderness areas, ranging from tiny islands to national parks that are several million hectares in size, as part of the National Wilderness Preservation System. However, conservation biologists suggest that to keep biodiversity and ecological integrity of wildness from being depleted, a minimum of 10% of the globeÊs land area should be protected. In fact, many existing reserves are too small to provide any real protection for the wild species that live on them and many existing preserves receive little protection. Currently, less than 2% of the worldÊs protected areas are at least 10,000 kmñ (3,900 square miles) in size. This is the conservative estimate of the minimum habitat required to maintain viable populations of the largest mammals. The United Nation Educational, Scientific, and Cultural Organization (UNESCO) proposed that at least one or more biosphere reserves be set up in each of the earthÊs 193 biogeographical zones. Each reserve should be large enough to prevent gradual species loss and should combine both conservation and sustainable use of natural resources. A well-designed biosphere reserve has three zones: 1.

a core area containing an important ecosystem that has had little or no disturbance from human activities;

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2.

a buffer zone where activities and uses are managed in ways that help protect the core; and

3.

a second buffer or transition zone, which combines conservation and sustainable forestry, grazing, agriculture, and recreation (Figure 2.4).

Buffer zones can also be used for education and research. In traditional parks and wildlife reserves, well-defined boundaries keep people out and wildlife in meanwhile biosphere reserves recognize peopleÊs needs for access to sustainable use of various resources in parts of the reserve. To date, more than 300 biosphere reserves have been established in 76 countries.

Figure 2.4: Typical design of a biosphere reserve

EXERCISE 2.2 Explain briefly what is biosphere reserve?

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LAND USE AND CONSERVATION

SELF-CHECK 2.2 What is the ecological important of forests?

Forests play an essential role in global biogeochemical cycles such as those for carbon and nitrogen. For example, photosynthesis by trees removes large quantities of carbon dioxide from the atmosphere and fixes it into carbon compounds. At the same time, oxygen is released into the atmosphere. Forests also influence local climate conditions. For example, 50 ă 80% of the moisture in the air above tropical forests comes from trees via transpiration and evaporation (evapotranspiration). Water from the soil is absorbed by roots, transported through the plant, and then evaporated from their leaves and stems. Forests are effective watersheds because they absorb, hold, and slowly release water. This provides a more regulated flow of water, even during dry periods, and helps to control floods. Forests provide lumber for housing, fuelwood, pulp for paper, medicines, and many other products worth millions (Figure 2.5). Over half of the worldÊs timber harvested for industrial use is consumed by the 20% of the worldÊs people who live in the HDCs (United States, Western Europe, and Japan).

Figure 2.5: Some of the potential products obtained from trees

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Incorrect forest management often results in low-diversity forests. There are generally two basic types of forest management systems: even-aged and unevenaged. With even-aged management, trees in a given stand are maintained at about the same age and size. Trees are harvested using monoculture techniques. Even-aged management begins with one or two cuttings of all or most trees from an area, the site is then usually replanted with seedlings of one or more species of the same age. In uneven-aged management, a variety of tree species in a given stand are maintained at many ages and sizes to foster natural regeneration. Here only the mature trees are selectively cut.

SELF-CHECK 2.3 If the worldÊs tropical forest are destroyed, in what way would it affect your life? Discuss.

Forests are being fragmented and degraded almost everywhere, especially in tropical countries. Satellite scans and ground-level surveys that are used to estimate forest destruction indicate that large areas of tropical forests are being cut. The lowest estimated rate of loss and degradation of remaining tropical forest is about 62,000 kmñ per year meanwhile the highest estimated rate is about 308,000 kmñ per year. Scientists estimate that this annual rate of destruction and degradation could well double in the decade. The destruction of all tree cover in an area is called deforestation. When tropical forests are harvested or destroyed, they no longer make valuable contributions to the environment or to the people who depend upon them. Tropical forest destruction particularly threatens native people whose cultural and physical survival depends upon the forests. Deforestation also causes the extinction of plant and animal species. Many tropical species, in particular, have very limited ranges within a forest, so they are especially vulnerable to habitat modification and destruction. When a forest is removed, the total amount of surface water that flows into rivers and streams actually increases. However, because this water flow is no longer regulated by the forest, the affected region experiences alternating periods of flood and drought. Uncontrolled soil erosion, particularly on steep deforested slopes, can affect the production of hydroelectric power if silt builds up behind dams. Increased sedimentation of waterways caused by soil erosion can also harm fisheries. In drier areas, deforestation can lead to the formation of deserts.

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LAND USE AND CONSERVATION

EXERCISE 2.3 1.

Name three general types of forest?

2.

How fast are the tropical forest being degraded or cleared?

3.

State the two major types of forest management.

2.1.4

Wetlands

Wetlands are habitats that are transitional between aquatic and terrestrial ecosystems. They are usually covered by shallow water and have characteristic soils and water-tolerant vegetation. Freshwater wetlands may be marshes, in which grass-like plants dominate, or swamps, in which woody plants (trees or shrubs) dominate. Wetlands, which occupy about 6% of the worldÊs land surface, were thought of as wastelands at one time. Today, the crucial environmental services that wetlands provide are widely recognized, and wetlands are somewhat protected by law. The main ecological and economic benefits of wetlands are: Ć

control flooding by acting as holding areas for excess water when rivers flood their banks. The floodwater stored in wetlands then drains slowly back into the rivers, providing a steady flow of water throughout the year.

Ć

serve as groundwater recharging areas. One of their most important roles is to help cleanse and purify water runoff, even water that is polluted. They do this by acting as a sink, a reservoir capable of trapping and holding pollutants in the flooded soil. Other pollutants, such as nitrogen from fertilizer runoff, are absorbed by wetland plants.

Ć

freshwater wetlands produce many commercially important products including wild rice, blackberries, cranberries, blueberries, and peat moss.

Ć

also use as a site for fishing, hunting, boating, photography, and nature study. Putrajaya is the first man-made wetlands undertaken in Malaysia (Figure 2.6). Construction of the Putrajaya wetlands began in March 1997 and was completed in August 1998. Among the objectives of this project are: (i)

to construct a wetland ecosystem that is unique to this part of the world

(ii)

to develop a natural habitat for conservation of indigenous wetland flora and fauna

(iii) to establish an environment suitable for public education and scientific research on wetlands

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(iv) to develop an aesthetically pleasing environment that enhances quality of life in Putrajaya and makes the city an attractive destination for domestic and international tourism.

Figure 2.6: A view of Putrajaya Wetland. a) The Upper West Wetlands with an extensive planting of macrophytes. The rockfill earth cored weir is used to retain water in the cell, and b) The Central Wetlands is one large cell with 50.9 hectares, where water purified by Upper North, Upper East and Lower East Wetland is collected before being discharged into the Putrajaya Lake (Khor 2002)

2.2

URBAN LAND USE

In the twentieth century, much of the worldÊs population has moved from rural to urban areas. In developing countries, urban areas are still growing rapidly as a result of population growth and rural poverty and unemployment. Most urban areas use some form of land-use planning to determine the best present and future use of each parcel of land in the area.

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2.2.1

TOPIC 2

LAND USE AND CONSERVATION

Urbanization and Urban Growth

Since the beginning of the Industrial Revolution some three hundred years ago, cities have been growing rapidly in size. They are now called urban areas - towns or cities plus their adjacent suburban fringes with populations of more than 2,500 people (although some countries set the minimum at 10,000-50,000 residents). A rural area is usually defined as an area with a population of less than 2,500 people. In a rural area, most residents depend on agricultural activities or other ways of harvesting natural resources for their livelihood. People in urban areas however, are not directly dependent on natural resource-based occupation. A countryÊs degree of urbanization is the percentage of its population living in an urban area. Urban growth is the rate of increase of urban populations. Between 1950 and 1998, the number of people living in the worldÊs urban areas increased 12-fold, from 200 million to 2.6 billion. This degree of urbanization varies in major areas of the world (Figure 2.7). By 2025 it is projected to reach 5.5 billion, almost equal to the worldÊs current population. About 90% of this urban growth will occur in developing countries. At current rates the worldÊs population will double in 47 years, the urban population in 22 years, and the urban population of developing countries in 20 years.

Figure 2.7: Degree (percentage) of urbanization for various groupings of countries in 1996. (Data from Population Reference Bureau)

The number of large cities is mushrooming. In 1960 there were 111 cities with populations of more than 1 million; today there are 293, and some analysts expect this number to increase to at least 400 by 2025. Currently, 1 person out of every

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10 lives in a city with a million or more inhabitants, and many live in the worldÊs 15 megacities (Figure 2.8) with 10 million or more people. However, the move to urban areas is not limited to the worldÊs 100 or so largest urban areas. The fastest urban growth is occurring in the 30,000 or so medium-size cities in developing countries.

SELF-CHECK 2.4 What causes urban growth?

Figure 2.8: The worldÊs 15 megacities - defined as 10 million or more inhabitants, as of 1995. (Data from United Nations)

Urban populations grow in two ways: by natural increase (more births than deaths) and by immigration (mostly from rural areas). Improved food supplies and better sanitation and health care in urban areas lower the death rate and cause urban populations to grow. Today, in developing countries the natural increase of the urban population is at least as important as migration. As cities are the main centres for new jobs, higher income, education, innovation, culture, better health care, and trade, people migrate to urban areas in search of jobs, a

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better life, and freedom from the constraints of village cultural life. They may also be pushed from rural areas into urban areas by factors such as poverty, lack of land, and declining agricultural work due to the use of machinery in agriculture.

EXERCISE 2.4 1.

State the differences between urban areas and rural areas.

2.

Give three reasons why rural people are migrated to the cities.

2.2.2

Transportation and Urban Development SELF-CHECK 2.5

What methods should we use to control the development of urban lands? Discuss.

If a city cannot spread outwards, it must grow vertically upward and downward (below ground), so that it occupies a small land area with a high population density. Most people living in such compact cities walk, ride bicycles, or use energy-efficient mass transit. Residents often live in multistory apartment buildings; with few outside walls in many apartments, heating and cooling costs are reduced. Many European cities and urban areas such as Hong Kong and Tokyo are compact and tend to be more energy-efficient than the dispersed cities in the United States, Canada, and Australia, where ample land is often available for outward expansion. A growing number of people in developing countries who cannot afford cars are still using motor scooters, which produce more air pollution than cars. Most burn a mixture of oil and kerosene in small, inefficient, and noisy engines that emit clouds of air pollutants. Because they are cheap, their numbers are increasing three times faster than cars and trucks in developing countries. One solution is to replace these smog machines with zero pollution and quiet electric scooters. Recently Taiwan and Indonesia have introduced air pollution control legislation that may spur the use of electric scooters. The major weakness of electric cars is their limited range. However, this is less of a problem with much lighter electric scooters.

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Globally, bicycles outsell cars by almost 3 to 1 because most people can afford a bicycle whereas fewer than 10% can afford a car. Besides being inexpensive to buy and maintain, bicycles produce no pollution, are rarely a serious danger to pedestrians or cyclists, take few resources to make, and are the most energyefficient form of transportation. In urban traffic, cars and bicycles move at about the same average speed. Using separate bike paths or lanes running along roads, cyclists can make most trips shorter than 8 kilometers (5 miles) faster than drivers. In China, at least 50% of urban trips are made by bicycle and the government gives subsidies to those who bicycle to work. Many cities in Western Europe and Japan have taken back the streets for pedestrians, cyclists, and children by banning cars or slowing motor traffic in residential and shopping areas. In Copenhagen, Denmark, bike lanes enable residents to make 25% of all urban trips by cycling, a figure that increases during summer. People there can rent bikes from special token-fed racks; when a bike is returned to any rack, the renter gets a full refund. An increasing number of European cities are closing off large downtown areas to all motor vehicles. Countries such as Western Europe and Japan have invested on comfortable, low pollution and high speed train ă the bullet train. Like other countries, Malaysia also invested in inter- and intra-city electric train services. Bus systems are more flexible than rail systems. They can run throughout sprawling cities and be rerouted overnight if transportation patterns change. Bus systems require less capital and have lower operating costs than heavy-rail systems. In Canada, the city of Ottawa, Ontario, is developing an extensive bus system instead of a subway system because of its much lower cost and greater flexibility in serving medium- and low-density urban areas.

EXERCISE 2.5 Explain why bus systems are still widely used instead of rail systems in most of the cities.

2.2.3

Urban Land Use Planning

Most urban areas and some rural areas use some form of land-use planning to determine the best present and future use of each parcel of land in the area. Because land is such a valuable economic resource, land-use planning is a complex and controversial process involving competing values and intense power struggles. Much land-use planning is based on the assumption that substantial future population growth and economic development should be

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encouraged, regardless of the environmental and other consequences. This leads to uncontrolled or poorly controlled urban growth. Zoning regulation and other alternatives are then used to control how the land is used wisely. Zoning can be used to control growth and protect areas from certain types of development. Principal zoning categories include commercial, residential, industrial, utilities, transport, recreation (parks and forest preserves), bodies of water, wetlands, floodplains, and wildlife preserves. Some cities, such as Portland, Oregon, and Curitiba, Brazil have used zoning to encourage highdensity development along major mass transit corridors to reduce automobile use and air pollution. Portland has used zoning to create large areas of green belts. These open green spaces usually contain plants, which absorb carbon dioxide and produce oxygen. Some plants even filter pollutants out of the air. In addition, trees provide shade, which cools the city during summer and provides some shelter from rain and snow. Local governments can also control the rate of development by limiting the number of building permits, roads, and other services. Local, state, and federal governments can also take other measures to protect cropland, forested land, and wetlands near expanding urban areas from degradation and ecologically unsound development. They can require an environmental impact analysis (EIA) for proposed roads and development projects. Land can be taxed on the basis of its actual use as agricultural land or forested land, rather than on the basis of its most profitable potential use. This would keep farmers and other landowners from being forced to sell land to pay their tax bills, but would decrease tax revenues for cities. Another way to provide open space and control urban growth is to surround a large city with a greenbelt (Figure 2.9). This arrangement can control urban growth and provide open space for recreation and other nondestructive uses. Satellite towns can be built outside the belt. Ideally, the outlying towns and the central city are linked by an extensive public transport system. Many cities in Western Europe and Canada such as Toronto and Vancouver have used this approach.

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Figure 2.9: A greenbelt around a large city

Japan and Western Europe have the worldÊs most comprehensive land-use controls, and North America and Australia the weakest. In the United States, only Oregon has developed a comprehensive land-use plan. Recently China began developing a comprehensive national zoning plan with the prime goal of achieving zero net loss of farmland to residential and industrial development.

EXERCISE 2.6 Explain the concept of greenbelt.

Land has multiple uses and benefits. The major global categories of land resources by human land use are agricultural lands, rangelands, wilderness and forests, and wetlands. These lands provide many essential environmental services. However, human activities sometimes degrade land to the point where it cannot provide essential environmental services. For example, a shortage of fertile land upon which to grow crops threatens our ability to provide enough food for the worldÊs growing population. Farmland is composed mainly of arable

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land and rangeland. Good arable land has fertile soil that supplies plants with mineral nutrients, water, oxygen, and support. Areas of earth that have not been greatly disturbed by human activities are called wilderness. It includes many different ecosystems, such as forest, rangeland, desert, and wetland. Forests provide many environmental services as well as commercially important timber. Currently, the greatest problem facing world forests is deforestation, which is the permanent removal of forest. During the twentieth century, much of the worldÊs population has moved from rural to urban areas. In developing countries, urban areas are still growing rapidly as a result of population growth and rural poverty and unemployment. This urbanization of human populations, combined with rapid population growth, affect almost everything about our lives, including our environmental problems, e.g., air pollution, Therefore, urban land- use planning is important to determine the best present and future use of each parcel of land in the urban area.

Biosphere

Desertification

Decomposer

Mass transit

Deforestation

Watershed

Multiple Choice Questions 1.

2.

Which of the following are the properties or components of soils? (a)

Humus.

(b)

Air.

(c)

Water.

(d)

All of the above.

The total amount of land surface on the earth: (a)

greatly exceeds that needed by people today.

(b)

does not adequately represent the land available for production of food

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3.

4.

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(c)

shows that there is far more opens space than needed by present day populations.

(d)

is much greater than the surface of the earth that is covered by water.

The total amount of land areas on earth is approximately: (a)

95 million km2

(b)

95 billion km2

(c)

145 billion km2

(d)

145 million km2

Below are the transport that categorized as mass transit except (a)

bus.

(b)

komuter.

(c)

train.

(d)

bicycle.

True False Questions 1.

The four major uses of the worldÊs land area are (True or false) agricultural lands, rangelands, widerness and forest, and wetlands.

2.

Organic fertilizers are added to soil to improve the soil (True or false) structure and as well as providing nutrients to the degraded soils.

3.

An urban area is an area with a population more than (True or false) 2,500 people.

4.

The destruction of all tree cover in an area is called (True or false) desertification.

5.

Worldwide, Japan has an efficient public transportation (True or false) network within metropolitan areas and between the large cities.

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Structured Questions 1.

Define the following terms: (a) Wilderness (b) Deforestation (c) Desertification (d) Wetland (e) Urban area

(2 marks) (2 marks) (2 marks) (2 marks) (2 marks)

2.

List FIVE (5) major properties of soils.

(5 marks)

3.

Give TWO (2) major types of ground transportation found in the cities.

(4 marks)

4.

Describe briefly TWO (2) ecological functions of forests.

(10 marks)

5.

Describe briefly what causes urban growth.

(10 marks)

6.

Explain briefly what is unique about the growth characteristics of grasses that enable them to survive despite moderate grazing pressure.

(10 marks)

7.

Greenbelt is another way to provide open space and control urban growth in a large city. Discuss briefly the concept of greenbelt.

(10 marks)

Cunningham, W.P. & Saigo, B.W. (1992). Environmental science: a global concern. USA: Wm. C. Brown Publishers. Jones, A.M. (1997). Environmental biology. London: Routledge. Khor, C.H. (2002). The Putrajaya Wetland project. Angkasa GHD Engineers Sdn Bhd (online), http://www.acssb.com.my/pdf/putraj.pdf. Krohne, D.T. (2001). General ecology. (2nd ed.). USA: Brooks/Cole, Thomson Learning Inc. Miller, G.T. (2000). Living in the environment: principles, connections, and solutions. USA: Brooks/Cole Publishing Company.

TOPIC 2

Population

Reference

Bureau.

LAND USE AND CONSERVATION

Annual. World population Washington, D.C.: Population Reference Bureau.

data

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sheet.

Raven, P.H., Berg, L.R. & Johnson, G.B. (1993). Environment. USA: Saunders College Publishing. Smith, R.L. & Smith, T.M. (2001). Ecology and field biology. (6th ed.). USA: Benjamin Cummings. United Nations. Annual. Demographic Yearbook. New York: United Nations.

Topic X Environmental

3

Degradation

LEARNING OUTCOMES By the end of this topic, you should be able to: 1.

Identify sources of air, water, waste and noise pollution;

2.

The impacts of pollutants to the ecosystem; and

3.

The impacts of pollutants to human beings.

X

INTRODUCTION

Pollutants contaminate the earth with substances that interfere with natural ecosystems. Although human activities are known to be the main contributor, natural phenomena such as volcanic eruptions, can also pollute to the earth. Pollutants are divided into two categories: biodegradable and non-degradable. Biodegradable substances are considered as pollutants when they are introduced into the ecosystem faster than the natural decomposition process. Nondegradable substances are materials that require a long period of time to decompose or cannot be decomposed. In this topic, you will be introduced to air, water, waste and noise pollution, point- and non-point sources of pollutants and the impact of pollutants to the environment.

3.1

AIR POLLUTION

Can you recall the following incidents? June 1991

: Eruption of Mt. Pinatubo in the Phillipines released tons of sulfur dioxide into the atmosphere.

November 1997 : Southeast Asian region, particularly Malaysia, Singapore and Kalimantan encountered severe air pollution (haze) due to the burning of agriculture lands in neighbouring country.

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March 2000

: Parts of Borneo were covered by blanket of smoke as a result of forest fire in the Sumatra Island.

June 2004

: Smog or haze due to the forest fire in Riau has covered parts of Penang, Kedah, Perak, Selangor and Kuala Lumpur.

The above are some of the most publicised source of air pollution in recent years. Most air pollutants are anthropogenic (man-made) sources; mobile sources (vehicles) and stationary sources (factories and plants). However, natural sources such as forest fires and volcano eruptions also emit air pollutants. The effects of air pollutants can be minor and reversible or harmful and fatal.

3.1.1

Sources of Air Pollution

Each year, millions of tons of pollutants are released into the air from both natural and anthropogenic sources. Most of the released pollutants are toxic and can cause serious health effects. Some of these pollutants can persist for considerable time in the environment and may accumulate in the food chain.

SELF-CHECK 3.1 Name 2 toxic air pollutants that can cause serious health effects.

Air pollutants could be categorized into 2 categories: mobile and stationary. The latter are divided into major sources and area sources. Figure 3.1 illustrates the breakdown of sources of pollutants based on 1996 National Toxics Inventory data (USEPA, 2000).

Figure 3.1: Sources of pollutants (USEPA, 2000)

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Mobile Sources Mobile sources are a major contributor of air pollutants in urban areas. Vehicles that we rely on for transportation are one of the mobile sources.

SELF-CHECK 3.2 Name 2 examples of stationary sources that can cause air pollution.

Below are some toxic substances emitted by mobile sources into the air: (i)

benzene present in fuel are released when the fuel evaporates.

(ii)

incomplete combustion emits toluene and xylene.

(iii) formaldehyde, acetaldehyde and 1,3-butadiene are some by-products of incomplete combustion though they are not present in the fuel. (iv) metals from engine wear or from impurities in oil or fuel.

Stationary Sources Stationary sources are divided into two categories: (i)

Major sources ă is defined as sources that emit 10 tons per year of CO, CFCs, HCFC, Pb, NOx, SO2, volatile organic compounds, radon and others. Usually manufacturing plants, chemical plants, steel mills, oil refineries and hazardous waste incinerators. Air pollutants could leak from equipments, during transferring of materials, or during discharge through emissions stacks or vents.

(ii)

Area sources ă is defined as sources that emit less than 10 tons per year of a single air pollutant or less than 25 tons per year of a mixture of air pollutants. Examples include petrol stations and vehicle workshops. Although emissions from individual area sources are relatively small, however, collectively their emissions can be significant.

3.1.2

Where Do Air Pollutants Go?

Air pollutants can be transported by wind. The distance travelled by pollutants are governed by factors such as weather condition, terrain such as mountains and valleys, the chemical and physical properties of the pollutant, concentration of the pollutant, physical and/or chemical changes, and whether it will remain airborne, deposit on land or water.

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Some pollutants remain airborne and create air pollution far from the source. Some pollutants can be deposited on land and water bodies by precipitation, or settling directly onto land or in water. Finally, deposited pollutants will pollute water bodies via storm water runoff. There are some air pollutants that degrade very slowly and some do not degrade at all. Examples of non-degradable air pollutants include heavy-metals like mercury and lead. These pollutants can remain in the environment (and also in human body) for a very long time.

SELF-CHECK 3.3 Why mercury and lead are known as heavy-metals?

3.1.3

Impact of Air Pollution

Toxic air pollutants are poisonous substances in the air that can harm the environment and our health. Living organisms (including humans) exposed to toxic air pollutants of varying concentrations and duration may increase their chances of getting cancer or other serious health effects. Other health problems include respiratory irritation, nervous system problems, birth defects, and interruption to hormone systems. Humans can be exposed to toxic air pollutants by: Ć

Breathing contaminated air

Ć

Consuming contaminated food products and water

Ć

Contact with contaminated soil, dust or water

Toxic air pollutants get into the human body mainly through breathing. If a pollutant enters the body, the pollutant may remain in the body (eg. in organs, such as lungs) or remove from the body by the digestive system or skin. It will be transported throughout the body by the blood system. As it moves all over the body, the pollutant can undergo chemical changes. The pollutant can be exhaled through urine, bowel, sweat, breast milk, stored in hair, bone or fat. Biomagnification is a phenomenon whereby predators usually accumulate greater pollutant concentration than their contaminated prey via the food chain.

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SELF-CHECK 3.4 Do animals experience the same health related problem when exposed to toxic air pollutants?

3.1.4

Acidification

Many scientists agreed that the burning of fossil fuels is the major cause of acidification. Acidification or commonly known as acid rain is caused by emissions of sulphur dioxide (SO2) and oxides of nitrogen (NOx). Acid rain forms when SO2 and NOx react with water, oxygen and oxidants to form acidic compounds (sulfuric acid and nitric acid). These compounds then fall to the earth as acid rain in two forms: - wet deposition ă acidic rain, fog and snow, and dry deposition ă acidic gases and particles. The acid deposition levels are high in some moderate developing countries (MDC) namely China, India, Thailand and Republic of Korea (World Resource Institute, 1999). Similar findings were reported by the UNEP (2000). They recorded that the rainfall in some MDCs are ten times more acidic than unpolluted rain.

3.1.4.1 Impact of Acidification (i)

Soil Acidification Soil acidification is the process whereby soil becomes acidic. Below are some of the important impacts of soil acidification. Plant nutrients are leached out ă Acidification of soil causes plant nutrients such as magnesium, potassium and calcium to deplete by going into solution. This will decrease soil pH and plants are unable to grow in this condition. Toxic metals are freed ă The concentration of aluminium ions will increase when soil is acidified. Aluminium ions are toxic to plants. Phosphates are bounded ă The increase in aluminium ions causes phosphate deficiency in plants. Phosphates will be bounded with aluminium ions to form aluminium phosphate. This form of phosphate is less accessible to plants. Besides this, other important micronutrients (molybdenum, boron and selenium) will also be less or inaccessible to plants.

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SELF-CHECK 3.5 How serious is the impact of soil acidification on plants in todayÊs world? Is it a serious issue that has caused many plantations to shut down? Discuss. (ii)

Acidification of Surface Water Surface waters such as lakes that have pH lower than 5.6 are classified as acidic. Once it becomes acidic, the concentration of inorganic aluminium will increase. High concentration of inorganic aluminium is toxic to aquatic organisms and causes the decrease in decomposition rate. If surface water is acidified, the water will become clearer because the humic substances will precipitate out and fall to the bottom.

Figure 3.2: Acidification formation and its impact

3.1.5

Air Pollution Control Efforts

The Geneva Convention on Long-range Transboundary Air Pollution was established in 1979 by the European communities. It was the first international agreement signed by 33 countries. This convention was established because scientists showed that air pollutants could travel several thousands of kilometres before deposition and cause damage. Besides the international cooperation for air

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pollution abatement, the Convention also enables institutional framework that brings together research and policy. Over several years, this convention has been extended by inclusion of eight protocols. The protocols are: Ć

1999

ă

Abate Acidification, Eutrophication and Ground-level Ozone

Ć

1998

ă

Reduce Persistent Organic Pollutants

Ć

1994

ă

Further Reduction of Sulphur Emissions

Ć

1991

ă

Control of Emissions of Volatile Organic Compounds

Ć

1988

ă

Control of Nitrogen Oxides

Ć

1985

ă

Reduction of Sulphur Emissions

Ć

1984

ă

Long-term Financing of the Cooperative Monitoring and Evaluation Programme.

Programme

for

Use the internet to identify the countries that participate in this convention.

3.2

WATER RESOURCES POLLUTION

Life may exist without air or light or heat, but it is impossible without water. Nearly 70% of the human body consists of water and nearly 70% of the EarthÊs surface is covered by water. Clean water is essential for human life, health, ecosystems and also economic growth. Humans require clean water for drinking, industry, agriculture, hydropower, waste disposal and health. Many scientists found that annually about 300-500 million tonnes of heavy metals, solvents, toxic sludge and other wastes accumulate in water resources. They also estimated that annually about 2.2 million people die because of diseases related to contaminated drinking water and poor sanitation. Improper and hasty urbanization also contributes to the increase in water pollution through sedimentation, solid waste and rubbish, and organic pollution. Many scientists predicts that by 2025, the demand of water will increase 50% more for MDCs, 18% more by HDCs and many parts of the earth (especially LDCs) will face water stress (International Year of Freshwater 2003 Fact Sheet, 2003).

TOPIC 3

3.2.1

ENVIRONMENTAL DEGRADATION

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Sources of Water Pollution

Sources of water pollution are divided into two categories: point-source and nonpoint source. (i)

Point Source Water pollutants that are discharged into a receiving water body are known as point source. Examples of point sources pollution are wastewater discharged from industries, municipal sewage treatment plants, and agricultural activities. Oil and chemical spills are also a threat to the water body. The control of point source pollution is relatively easier to counter and regulate compared to the non-point source pollution. In Malaysia, any factory or industry which are found guilty of illegal discharging of illegal wastes will be charged under the Environmental Quality (Sewage and Industrial Effluents) Regulations 1979.

(ii)

Non-Point Source Non-point source are pollutants generated by human activities all over the water bodies. The primary non-point source pollutants are sediments, nutrients and faecal bacteria. Combating non-point sources is a huge task compared dealing with point source pollution. In most MDCs, rivers are used as a mode of transportation and rivers are considered as the easiest way of disposing unwanted materials. Despite the current rapid development, especially in Asia, most people dispose their wastes into rivers. Furthermore, due to improper non-centralized and poorly maintained sanitation facilities, particularly in squatter areas, results in pollutants ending in rivers. Poor civic conscious also contributes to the nonpoint source, like throwing rubbish into the sea by beach goers.

3.2.2

Impact of Water Pollution

3.2.2.1 Human Health The effect of toxic contaminants on human health can be classified as either acute or chronic. Substance that is able to cause serious illness or death within 48 hours after exposure is regarded acute toxicity. Chronic toxicity is the long term effect of health because of frequent exposure to small amounts of toxic substance. Kidney and liver disease, cancer and mental illness are some of the examples of chronic toxicity. Drinking of contaminated water can also pose a threat to our health, especially when it contains heavy metals such as mercury, lead, cadmium and arsenic. In 1996, Bangladesh was threatened by arsenic poisoning and about 1420 Bangladeshis were affected (APPEN, 1998). Table 3.1 below illustrates the effects of consuming some of the common heavy metals.

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Table 3.1: Health Effect of Consuming Certain Heavy Metals Heavy Metals

Effects on Human

Arsenic

Weight loss, nausea, diarrhoea, and loss of hair

Cadmium

Kidney disease, mutation and hypertension

Lead

Cumulative poison, kidney damage, anaemia, nerve damage, death

Mercury

Hallucinations, gingivitis, brain damage

SELF-CHECK 3.6 Name 2 substances that contain heavy metals.

Pathogens Water related diseases are reportedly getting worse in MDCs. Almost 80% of diseases are water related (APPEN, 1998). Pathogenic organisms such as bacteria, viruses and parasites are easily spread by polluted water. Pathogenic organisms (e.g. Vibrio cholerae) usually propagate in faecal matter. Vibrio cholerae is the cause of cholera. Infected individuals suffer severe diarrhoea, body dehydration, serious salt imbalance which could damage the normal function of vital organs, and death (in severe condition). APPEN (1998) reported that diarrhoeal disease kills over 1.5 million children annually. Poliovirus is another example of disease that is caused by pathogenic organisms. Poliovirus usually attacks the alimentary tract and can cause symptoms like fever, vomiting and diarrhoea. This virus can cause paralysis to individuals if it enters into the bloodstream and death, if this virus attacks the respiratory system. Another virus that is transmitted by consuming contaminated water is Hepatitis A.

Recently, coliforms were detected in Tasik Chini. What are the effects of consuming coliforms? Discuss it in your forum.

3.2.2.2

Agricultural Activities

Agricultural activities are identified as a major contributor to water pollution. Agricultural activities use a substantial amount of pesticides and fertilizers to

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obtain maximum yield. Excessive use of certain fertilisers may be harmful to plants. Boron, for example, is required by plants in trace amounts, however, excess of it, is toxic. These substances, in most cases, are washed away by rainwater or leeched into the ground before the plants can utilise it. The water bodies will then be contaminated by these substances. The practise of using animal faeces as fertilisers can cause diseases to plants and human as unhealthy animals may produce faeces that contain certain harmful microorganisms. Improper management of farms also causes serious water contamination. Foods, furs, and faeces are some common wastes in farms. Improper management of these wastes can cause illness to the animals as well as to humans. The presence of oil and heavy metal substances in the ocean are usually derived from boats and ships. Mercury and lead are heavy metals that easily accumulate in fishes. When we consume contaminated fish, heavy metals are transferred into our body.

3.2.2.3

Eutrophication SELF-CHECK 3.7

What is Eutrophication?

Eutrophication is the gradual nutrient enrichment of land locked water bodies by an inflow of land-sourced nutrients. It is a natural process that is a part of the life cycle of water bodies but has been speeded up and exaggerated by man. Is eutrophication a treat to the ecosystem? The answer for this question can be both Yes and No. The deposition of nitrogen benefits most plants as nitrogen compounds is one of the macronutrients required. However, human activities such as agricultural runoff, sewage discharges and urban runoff are believed to have exaggerated the eutrophication process. The influx of nutrients and organic substances interrupts aquatic ecosystems and promotes the growth of algae. The algal blooms impair the aquatic ecosystem by: Ć

clouding the water and blocking the sunlight

Ć

decomposition of algae uses oxygen

Ć

certain algal species, such as blue-green algae and marine dinoflagellates produce toxins which could affect the health of aquatic organisms, birds and humans.

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3.2.3

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ENVIRONMENTAL DEGRADATION

Water Control Efforts

Water is an important natural resource and to overcome water pollutions, cooperation from various agencies, public and private sectors is required. It is vital to raise the level of awareness of the public about the seriousness of water pollution and how they can help to overcome it. With regards to this, various water control efforts programmes have been conducted by government and private agencies and include: Ć

National Water Resources Master Plan, 8th Malaysia Plan (2000-2005)

Ć

3rd Outline Perspective Plan (2001-2010)

Ć

Formation of national and state water authority such as National Water Resources Council (1998)

Ć

Selangor Water Management Authority (LUAS)(1999) and Sarawak Rivers Board.

Ć

WWF Malaysia ă Forests for Water, Water for Life Programme (1998-2002) and Partners for Wetlands: Kinabatangan River, Sabah (since 1998).

Visit the following websites and discuss the effectiveness of their activities in your forum. Malaysian Water Partnership: http://didnet.moa.my/MyWP/ The WorldÊs Water: www.worldwater.org WWF-Malaysia: www.wwfmalaysia.org

3.3 3.3.1

SOLID AND HAZARDOUS WASTE Municipal Solid Waste

Waste is something that people do not want. Municipal solid waste is waste or garbage generated from residential and commercial sources. Generally, municipal solid waste can include some or all of the following: Ć household wastes Ć household hazardous wastes Ć street garbage Ć parks and garden wastes Ć wastes from institutions, commercial and offices

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Municipal solid waste does not include sewage, hazardous waste, nonhazardous industrial waste, construction debris, or automobile waste. Various studies show that quantities of waste increases significantly with the wealth and the industrialised nature of society.

3.3.2

Wastewater

How often do you wash your car? Do you know where the water is headed to? Wastewater collected and processed is returned to receiving waters or to the land or reused. The fundamental function of wastewater treatment is to accelerate the natural processes of cleaning the wastewater. The stages involved in wastewater treatment are preliminary, primary, secondary and tertiary treatment. Below briefly discuss the stages in wastewater treatment. Ć

Preliminary stage ă large objects such as rags, sticks, and stones are removed. These materials may clog pipes or damage equipments.

Ć

Primary stage ă removal of suspended solids and organic matter. Biosolids is the materials that sink at the bottom of the tank. Biosolids can be used as fertilizer.

Ć

Secondary stage ă suspended solids and organic matter are further reduced. The trickling filter and activated sludge process are some common techniques used in this stage.

Ć

Tertiary stage ă chlorine will be added into the water to kill pathogenic bacteria and reduce odour.

Discuss the advantages and disadvantages of using chlorine as a disinfectant?

3.3.3

Hazardous Waste

Hazardous waste is usually a by-product of a manufacturing process. Most of our daily consumption is made from chemicals, these includes papers, plastics, medicines, foods, electronic equipments and many more. When hazardous substances are discarded, they are called hazardous waste. According to the United States Environmental Protection Agency, hazardous is defined as:

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any waste or combination of waste of a solid, liquid, contained gaseous, or semisolid form which because of its quantity, concentration, or physical, chemical, or infectious characteristics, may (1) cause or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness; or (2) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported or disposed of, or otherwise managed. Some hazardous waste are generated by households. Examples of hazardous waste generated by households includes batteries, spray cans, paint thinner, and pesticide containers. Usually hazardous waste have one or more of these properties ă corrosive, flammable, reactive, toxic and carcinogenic. Examples of include mercury, lead, chlorine and arsenic. Organism can be exposed to hazardous substances through inhalation, ingestion or dermal exposure. Exposures can be either acute or chronic. Acute exposure is a single exposure of hazardous substances for a short time and chronic exposure is repeated exposure of hazardous substances for a longer period of time.

3.3.4

Waste Management

Waste management is an uphill task. It requires commitment from the local authorities (law enforcement, environmental act, town planning) and from the communities (source reduction, recycling, proper disposal of waste). In managing solid waste, source reduction program should be prioritised, followed by recycling programs, and finally, proper waste disposal methods. Source reduction means reducing waste by simply not producing it. Source reduction includes purchasing durable goods and purchasing products that are free of toxic substances. Apart from that, source reductions conserve resources and prevent the formation of greenhouse gases. Recycling is simply turning or making waste into valuable resources. Recycling prevents emission of greenhouse gases, conserves energy, creates jobs, conserves resources and reduces the need for new landfills and combustors. Composting is a controlled aerobic biological decomposition of organic matter into humus. Compost acts as a natural fertilizer, providing nutrients to the soil, and reduces the use of chemical fertilizers and pesticides. Combustion is the controlled burning of waste. Combustion is usually used for wastes that are non recyclable or composted. The combustion process can emit toxic substances into the atmosphere. However, the emission of toxic substances

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can be controlled by installing control equipment such as acid gas scrubbers and fabric filters in the combustors.

Search the Internet about the advantages and disadvantages of incinerators.

Landfills are often regarded as the last choice in waste management. This is because of improper managed landfills and unsuitable landfill locations can contaminate groundwater, attract disease carrying insects, and even cause fires. Could you recall the incident of Taman Beringin Landfill, Kuala Lumpur that caught fire in February 2004? However, well designed, constructed and managed landfills provide an option to treat waste. A typical well designed landfill has good ventilation system, to burn or collect methane. Methane collected can be used to generate electricity. By reducing the amount of waste generated, source reduction helps in promoting the efficient use of the natural resources.

3.3.5

Advance Treatment of Waste

With the advancement in technology, new methods are constantly being developed to treat waste. An example is bioremediation which is using organisms to clean our waste. The living organisms could be from as small as fungus and bacteria to worms and plants. As discussed earlier, composting is a process of converting organic matters into humus. Compost bioremediation is the use of microorganisms to break down contaminated water or soil. Waste from humans could be food for microorganisms. Some microorganisms are able to digest, metabolise and transform our wastes into humus, CO2, water and salts. Phytoremediation is the use of plants to remediate contaminated soil or groundwater. Plants are employed because of their ability to take-up, accumulate, store or degrade organic and inorganic substances. This process is currently labelled as green technology as this process is environmentally friendly, cost-effective, able to degrade waste and also prevents erosion. Vermiculture or the process of using earthworms to convert organic waste is currently being investigated by Malaysian scientists. The scientists found that certain species of worms are able to degrade household wastes (which consists high organic matters) into fertilizer. Besides able to degrade organic waste, worms are able to improve soil condition.

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Visit OUMÊs digital library, search for articles about bioremediation, phytoremediation and vermiculture articles in the SpringerLink journal. Discuss the effectiveness of the above techniques in your online forum.

3.4

NOISE POLLUTION

How would you define noise pollution? Is playing of rock songs or engine roaring or people chatting considered as noise pollution? Noise pollution is not easy to define. Loud music or roar of engines may be enjoyable by certain individuals but to others, it is a nuisance. Noise is basically unwanted sound. Noise is part of our lives (television, radio, children crying or laughing, vehicles that we use). Noise pollution is different compared to other form of pollutants and is considered as temporary compared to other kind of pollutants. Once noise stops, the environment is free of noise pollution. Furthermore, it is difficult to determine how much of loud noise is harmful as individuals can have different tolerance levels.

3.4.1

Sources of Noise

Decibel (dB) is the unit SI used to measure sound intensity. Sound intensity is defined as magnitude of fluctuations in air pressure caused by sound waves. According to U.S. Environmental Protection Agency (EPA), exposure to more than 70 dBA for 24 hour/day is hazardous to human ears. Figure below illustrates the intensity of some work related noise (NIOSH, 2001).

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Figure 3.5: Estimation of work-related noises Source: NIOSH, 2001

3.4.1.1 Noise from Machines We depend heavily on machines, from vacuum cleaners, air conditioners to heavy machinery that built vehicles and food industries, to name a few. The mechanical industry creates serious noise problems. Noise generated from machines is mainly caused by frictions and the noise generated often increases with the power of the machines. The noise generated can contain low or high frequencies, and have unpleasant and disruptive temporal sound patterns. Usually workers that deal with these machines wear protective ear plugs.

3.4.1.2 Noise from Vehicles Noises derived from road, rail and air, is the primary source of noise pollution in this century. Often, huge vehicles emit more noise compared to smaller vehicles. Noises derived from road usually come from vehiclesÊ engines and frictional contact from vehicle and the road surface and air. In airports, most workers wear protective ear plugs because aircraft operations generate extensive noise, especially during aircraft take-offs and landings. In view of the intensity of noise generated, airports are usually located faraway from residential areas.

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SELF-CHECK 3.8 Visit to a tyre shop and ask whether is there any „quiet‰ tyres. Which road surface generates more noise, driving on tar or cement road?

3.4.1.3 Noise from Constructions You have decided to hang your graduation picture in your house. Could you hammer the nail without making any noise? Construction, excavation and earth works often generate substantial noise. Noise from construction can come from cement mixers, welding, hammering, sawing, lorries, cranes and others. Most of these noise are usually inevitable as most construction equipments are often poorly silenced nor well maintained.

3.4.1.4 Noise from Domestic and Leisure Activities In residential areas, noise may stem from mechanical devices (e.g. hair dryers, washing machines and blenders), as well as voices, music and other materials (lawn movers, parties and others). Some types of indoor concerts and discotheques can produce extremely high level of noise that may bring discomfort to nearby residents.

3.4.2

Effects of Noise Pollution

Like other kind of pollutions, noise pollution can also affect our health. Effects of noise pollution can be temporary or permanent. The degree of annoyance acceptance of noise pollution varies with individuals. Researchers found that noise pollution is dangerous as it can cause stress, aggression, sleep disturbance depression, nervousness, high blood pressure, ability to focus and memorize and other illnesses. Some of the effects of noise pollution will are listed below.

SELF-CHECK 3.9 Is answering phone calls while watching movies in cinemas considered

as noise pollution? Ć

Cardiovascular and physiological effects

Ć

Damage on buildings due (e.g. supersonic aeroplanes)

Ć

Interrupt mating of animals

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Controlling Noise Pollution

With the advancement in technology, new tools and gadgets are created to assists humans in performing various tasks. Usually, this new equipment is more environmental friendly than its predecessors. The 2-stroke engine of motorcycles are being replaced with 4-stroke engines as the latter it is more environmental friendly and generates less noise. Below are some of the methods of controlling noise pollution. Ć

Reducing traffic noise - proper town planning, the use of hybrid and electric cars, development of tyre technology and road surface technology can also reduce the traffic noise.

Ć

Education - Education is one of the best method of controlling noise pollution.

Ć

Law enforcement - Emission standards for vehicles, construction equipments and industry machineries must be set and adhered to. Some Malaysian highway operators have erected sound barriers to reduce the noise from affecting surrounding residents.

We have invented many machines and gadgets to ease our lives without adequate awareness of the consequences of disturbing the fragile environment. In this topic, we have discussed the effects of various pollutants on human and as well as to other living organisms. Efforts of controlling and reducing pollutants were also being discussed. Various international and local organizations have been established to formulate methods to reduce and prevent further pollutants from damaging the environment.

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Acidification Biomagnification Bioremediation Eutrophication

Municipal solid wastes Non-point source Phytoremediation Point source

Multiple choice questions: 1.

2.

3.

Which of the followings is NOT considered as the major mobile air pollutants? (a)

Motocycles

(b)

Smoking

(c)

Cars

(d)

Lorries

Why a substance is known as a pollutant? (a)

The substance may cause sickness to human.

(b)

The substance may cause sickness to animals.

(c)

The substance may remain in the environment for a period of time.

(d)

The substance cannot be degraded by human.

Which of the followings is NOT the impact of soil acidification? (a)

Important plant nutrients are leached out.

(b)

Concentration of aluminium ions will increase.

(c)

Concentration of phosphates will increase.

(d)

Concentration of phosphates will decrease.

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4.

5.

ENVIRONMENTAL DEGRADATION

(a)

Deposition of nitrogen compounds into water bodies is known as eutrophication.

(b)

The use of plants to remediate wastes is known as phytoremediation

(c)

Municipal solid wastes includes sewage and hazardous wastes

(d)

Non-point sources of water pollutants are difficult to monitor.

Which of the following is the BEST method for waste management? (i)

Recycling of waste

(ii)

Reduction of waste

A. B. C. D.

(i) and (ii) (ii) and (iii) (i) and (iii) (i,) (ii) and (iii)

The methods of controlling noise pollution are by: (i)

proper town planning

(ii)

education

(iii) using recyclable products A. B. C. D. 7.

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Which of the following statements is FALSE?

(iii) Reusing of waste

6.

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(i) and (ii) (ii) and (iii) (i) and (iii) (i,) (ii) and (iii)

Which of the following are TRUE about bioremediation? (i)

The use of microorganisms to degrade wastes

(ii)

The microorganims used include bacteria and fungus.

(iii) The use of microorganisms to produce food products. A. B. C. D.

(i) and (ii) (ii) and (iii) (i) and (iii) (i,) (ii) and (iii)

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8.

9.

10.

1.

ENVIRONMENTAL DEGRADATION

Which of the following water pollutions is difficult to challenge? A.

Wastes disposed by factories.

B.

Wastes from agriculture activities

C.

Wastes from squatter areas.

D.

Oil spills from oil tankers.

Eutrophication is the excess of A.

pathogens.

B.

microorganisms.

C.

carbon dioxide

D.

nitrogen.

Which of the following methods is the LEAST preferred type of waste treatment? A.

Combustion

B.

Use of incinerators

C.

Composting

D.

Landfill

(a)

Define: (i) mobile sources of air pollution (ii) stationary sources of air pollution

(2 marks) (2 marks)

Give TWO (2) examples for mobile and stationary sources of air pollution.

(4 marks).

(c)

How does acidification occurs?

(4 marks)

(d)

Define and state the impacts of soil acidification.

(8 marks)

(a)

Define: (i) point sources of water pollution. (ii) non-point sources of water pollution.

(2 marks) (2 marks)

Give THREE (3) examples of point and non-point sources of water pollution

(6 marks).

Discuss how agricultural can pollute water bodies.

(10 marks)

(b)

2.

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(b) (c)

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ENVIRONMENTAL DEGRADATION

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(a)

Define hazardous wastes

(2 marks)

(b)

Give THREE (3) examples of household hazardous wastes. (3 marks)

(c)

What are the common properties of hazardous wastes?

(d)

Discuss the stages involved in wastewater treatment.

(3 marks) (12 marks)

Asia-Pacific PeopleÊs Environment Network, APPENS (1998). Water Watch: A Community Action Guide. WaterWatch Asia, Penang, Malaysia. International Year of Freshwater http://www.wateryear2003.org/en

2003

Fact

Sheet

(2003).

National Institute for Occupational Safety and Health, NIOSH (2001). General Estimates of Work-Related Noises. Publication No. 2001-104. UNEP (2000). Global Environment Outlook, GEO-2000. Alternative Policy Study: Reducing Air Pollution in Asia and the Pacific. UNEP. http://www.unep.org/Geo2000/aps-asiapacific United States Environmental Protection Agency, USEPA (2000). Taking Toxics Out of the Air. EPA-452/K-00-002. World Resources 1998-1999. http://www.wri.org/wr-98-99/acidrain.htm World Resources Institute (1999). The Global Commons: Acid Rain: Downpour in Asia?

Topic X Global

4

Environmental Issues

LEARNING OUTCOMES By the end of this topic, you should be able to:

X

1.

State the formation and importance of ozone layer;

2.

Identify the causes of ozone depletion and the process that degrade ozone;

3.

Identify the impacts of ozone depletion;

4.

Identify the effects of greenhouse gases on the environment;

5.

State the potential impacts of climate change; and

6.

State the impacts of sea level rise.

INTRODUCTION

So far we have looked at environmental pollution at a local to regional scale and discussed ways of combating this. However, the biggest problems facing the human race may be widespread environmental degradation on a global level. The main problems at this level are climate change (global warming) and ozone depletion. These problems are beyond the control of any single government, let alone individual, and have to be approached from a global cooperation standpoint. This topic examines these problems in detail and introduces some of the current agreements and solutions.

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4.1

GLOBAL ENVIRONMENTAL ISSUES

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ATMOSPHERE

The function of the atmosphere is to provide gases that are support life, absorbs harmful ultra-violet radiations, and protects the earth from space debris. The EarthÊs atmosphere contains various gases ă nitrogen (78%), oxygen (21%), carbon dioxide (0.03%), argon (0.93%) and others (0.04%). The atmosphere consists of several layers ă troposphere, stratosphere, mesosphere and thermosphere. Table 4.1 below summarizes the characteristics and the uses of these layers. Figure 4.1 illustrates the atmospheric layer. Table 4.1: Characteristics of the Atmospheric Layer Atmospheric Layer

Characteristics

Troposphere

About 9-15km above EarthÊs surface, most dense, weather occurs, temperature decrease with altitude

Stratosphere

About 48km above EarthÊs surface, drier and less dense than troposphere, temperature decrease with altitude

Mesosphere

About 80km above EarthÊs surface, temperature increase with altitude

Thermosphere

About 600km above EarthÊs surface, temperature increase with altitude to 1,700ÀC!

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Figure 4.1: The atmospheric layer

Ozone is a very small layer of the atmosphere. The presence of the ozone layer is vital to living matters. The ozone layer is located in the upper part of the atmosphere, called the stratosphere. This layer protects organisms (including us) from harmful ultraviolet radiation from the sun. In the mid-1970s, scientists found that some substance produced by man could destroy and deplete this layer. Since then, many scientists throughout the world have provided a broad and scientific understanding of the process of ozone destruction.

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What is Ozone?

The word ozone is derived from the Greek word „ozein‰ which means „to smell‰. Ozone has a pungent odour, reacts rapidly with many chemical compounds and is explosive in concentrated compounds. It is also toxic. The ozone layer is usually thinnest at the equator and denser towards the poles.

4.1.2

Importance of Ozone

Ozone functions as a filter or a protective radiation shield which prevents dangerous ultraviolet radiation from harming living organisms. Moreover, scientists believe that the presence of ozone in upper troposphere contributes to the global warming.

4.1.3

Ozone Formation

The atmosphere consists of approximately 21% oxygen. About 90% of ozone is found in the stratosphere and remaining 10% ozone is found in the troposphere. The formation of ozone layer is summarized in 2 steps: Step 1:

An oxygen molecule (O2) is broken into two oxygen atoms (O) by ultraviolet radiation from the Sun.

Step 2:

An oxygen molecule (O2) combine with an oxygen atom (O) to produce an ozone molecule (O3).

Figure 4.2: Ozone formation Source: Fahey, 2002

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GLOBAL ENVIRONMENTAL ISSUES

Causes of Ozone Depletion

There are many causes of ozone depletion, by natural gasses and also human activities. Below briefly discusses the causes of ozone depletion. (i)

Natural gasses

Carbon dioxide Carbon dioxide (CO2) is usually a by-product of organisms, fermentation and burning of fossil fuels. Atmospheric CO2 concentration increased from 280ppm in pre-industrial revolution to 365ppm in 1998 (IPCC, 2001).

Nitrous oxide Nitrous oxide (N2O) is released into the atmosphere by denitrification by microorganisms, vehicle emissions and nitrogen based fertilizers. It is estimated that N2O can remain in the atmosphere for about 120 years and about 170 times greater destruction power compared to carbon dioxide.

Methane Methane (CH4) is released from the decomposition of organic matter, landfills, and digestive processes. It is estimated that methane is about 24 times greater destruction power compared to carbon dioxide. (ii)

Human activities

Chlorofluorocarbons Chlorofluorocarbons (CFCs) were once considered as a marvellous substance for many industries. The CFCs are stable, inflammable, low in toxicity and cheap to produce. The CFCs are mainly used in refrigerators, solvents, and aerosol propellants (pesticides).

Other chemicals Chemicals such as carbon tetrachloride, methyl bromide, methyl chloroform and halons are also ozone depletion substance. Carbon tetrachloride and methyl chloroform are used as solvents in industrial applications, methyl bromide is used in soil fumigant, and halons are used in fire extinguishers. The CFCs and chemicals are found to release chlorine or bromine when they disintegrate. The release of chlorine and/or bromine into the atmosphere damages the ozone layer. Bromine atoms are more dangerous compared to chlorine atoms. Bromine atoms are about 40 times more destructive than chlorine atoms.

SELF-CHECK 4.1 What is the unit used to measure the amount of ozone in the atmosphere?

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EXERCISE 4.1 1.

Name 3 natural occurring and 3 man made greenhouse gases.

2.

State the functions of the atmosphere.

4.1.5

Ozone Depletion Process

The initial cause of the ozone depletion is the emission of ozone depletion substances mainly by human activities. Most of these substances accumulate in the lower atmosphere, the troposphere and is transported to the stratosphere. These stable substances are converted into reactive halogen gases by ultraviolet radiation from the sun. The following flow chart summarises the ozone depletion process.

Figure 4.3: Ozone depletion process Source: Fahey, 2002

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SELF-CHECK 4.2 CFCs are „heavy‰ gases. How does it get into the stratosphere?

4.1.6

Ozone Destruction by Chlorofluorocarbons

Chlorofluorocarbons (CFC) are extremely stable gases. However, the CFCs are hazardous when they are exposed to UV radiation in the stratosphere. UV radiation will break the stable CFCs and release atoms of chlorine, bromine and monoxides. The ozone destruction is illustrated in Figure 4.4 below. The destruction cycle consists of two reactions: ClO + O and Cl + O3. The end product of this is the release of two oxygen molecules. In this reaction, Cl is the catalysts. It is estimated that each CFC molecule can destroy up to 100,000 ozone molecules.

Figure 4.4: Ozone destruction Source: Fahey, 2002

SELF-CHECK 4.3 What is the function of a catalyst?

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The Ozone Hole

The „ozone hole‰ is the loss of stratospheric ozone. The British scientists began measuring the Antarctic ozone in 1957 and the objective was to understand the importance and function of the ozone layer. The ozone hole was discovered in Antarctic in the 1970Ês. These scientists found that the Antarctic ozone layer was consistent in the past; however, beginning of 1984, they observed that the ozone layer was progressively decreasing. Scientists recorded the ozone hole was over 23 million km2 in 1994, 30 million km2 in 2000 and 28 million km2 in 2003.

Visit The British Antarctic Survey website at http://www.antarctica.ac.uk. Search about the current status of the ozone layer and discuss how you could help to the ozone layer in your forum.

The ozone hole not only occurs in the Antarctic. Abarca and Casiccia (2002) found that about 12% loss of ozone occurred at Punta Arenas, Chile, 8% in southern Australia (Manin et. al., 2001) and 10-15% in New Zealand (McKenzie et. al., 1999).

4.1.8

Impact of Ozone Depletion

Scientists have studied the effects of ozone on human health for many years. Ozone layer removes or filters dangerous UV-A and UV-B radiation (see Figure 4.5). Exposure to UV-A radiation causes premature aging of the skin. Exposure to UV-B radiation causes cellular DNA damage. UV-A radiation is not strongly absorbed by the ozone layer. Numerous studies found that people who live in high altitudes and in the tropics are exposed to UV-B radiation more because the ozone layer is thinner in the tropics. Among the major health effects caused by the ozone depletion are skin cancer, cataracts, asthma, lung damage, pneumonia and bronchitis. Ozone depletion also damage plants and ecosystem, where plants unable to produce and store foods and are more prone to diseases. Increased in UV-B radiation also causes damage to forest ecosystems and decreases populations of phytoplankton in oceans.

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Figure 4.5: UV protection by the ozone layer

EXERCISE 4.2 What is the effect of prolonged exposure to UV-A and UV-B?

4.2

GLOBAL WARMING

Earth has provided life to all organisms ă Human are changing the climate of the earth ă by deforestation for development, smoggy environment (burning, transportation, etc) excessive use of fossil fuels, mountains of wastes (nonbiodegradable products), murky waters and much more. Human activities are slowly but surely changing the environment. Some of the evidence of the change of environment is the rise in temperature (e.g. in Cameron Highlands and Genting Highlands), floods and droughts, rising sea levels and new diseases (Nipah virus and SARS).

4.2.1

Greenhouse Effect

Greenhouse is a natural occurring phenomenon. In an unaltered environment, the earth absorbs and reflects and emits solar radiation back into the space. With

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the aid of natural greenhouse gases (CO2, CH4, N2O, O3) and absorption of solar radiation by the earth surface, the earth is able to sustain life. Figure 4.6 below illustrates the sunÊs radiation pathway. Without the greenhouse effect, the earth would be extremely cold!

Figure 4.6: Energy from the sun

The Intergovernmental Panel on Climate Change (IPCC) defines the greenhouse effect as a function of the concentration of water vapour, carbon dioxide and other trace gases in the atmosphere that absorbs the radiation leaving the surface of the Earth. The variation of greenhouse gases can alter the balance of energy transfer between the atmosphere, space, land and ocean. Scientists and environmentalists believed that human activities are the primary reason that caused the increase in greenhouse gases. With the creation and use of non- environmental friendly products (also natural phenomena) fewer radiations are emitted back into the space and thus, increase the earthÊs temperature. Furthermore, the ability of the atmosphere to filter ultraviolet radiations is further reduced ă creating ozone hole and further increase earthÊs temperature.

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Visit an agricultural farm that have glasshouses. Compare the interior and exterior environment of the glasshouse. Discuss your findings in your forum.

4.2.2

Climate Change

Climate change may lead to health effects that are direct and indirect. However, to some regions, climate change would be beneficial. For example, the winter cold would become milder or more extreme. Can you still recall the incidents of drought in our country? What are the immediate health effects? The direct health effects caused by the climate change are extreme temperatures, increase in respiratory illnesses, sudden and deadly storms, increase in floods due to increased in rainfall (and also due to poor mitigation) and droughts. The change of climate causes indirect health effects that may increase and also bring new diseases ă to human and to animals. Abrupt climate change will also lower certain food crop production. Sea levels are expected to rise due to the increase in global temperature. Recently, there are many reports of the rise of sea level, Bangladesh is the most vulnerable. As a whole, climate change will affect ecological systems. (a)

Changes in Temperature Globally, 1998 was the warmest year and the 1990s was the warmest decade recorded. The global mean surface temperature in 2003 was 0.46ÀC above the 1961-1990 annual average (World Meteorological Organization, 2004). In 2003, the WMO reported that the European communities suffered extreme heat waves. Glacial loss was nearly twice as much as the 1998 record. In Asia, several countries were hit by a heat wave in May 2003 (India, Pakistan and Bangladesh). The WMO reported that the temperature recorded ranged between 45ÀC and 49ÀC. About 1500 people were reported killed by heat strokes. Botswana, Zimbabwe and Mozambique suffered severe drought in early 2003. Malaysia too experienced drought. Several states in Malaysia also encountered droughts in 1991.

(b)

Rainfall and Flooding Some countries encountered an increase in rainfall and resulted in severe flooding. In 2003, WMO reported that the Ganges River rose to its highest

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level since 1975. Due to this, many flood-related deaths were reported in 2003. In the same year, China encountered extra ordinary heavy monsoon rains that flood the Yellow River. Total death reported about 2000 and many homes were destroyed. In the African countries, WMO reported that Kenya, parts of Ethiopia and Somalia were flooded due to El-Nino. Parts of Kuala Lumpur also were flooded in October 2001.

4.2.3 (a)

Potential Impacts of Climate Change for Tropical Asia

Ecosystems and Biodiversity This section discusses briefly the potential impacts on terrestrial ecosystems which includes tropical forests, freshwater wetlands, crop biodiversity, coral reefs, and mangroves. Figure 4.7 below illustrates the summary of the potential impacts of some components of climate change.

Figure 4.7: Summary of the potential impacts of some components of climate change

(i)

Freshwater Wetlands Freshwater wetlands or peatlands contain large accumulation of decomposed organic matters. They are known for their ability to store water, reduce floodwater and provide water during droughts. The viability of peatlands is likely to have negative impacts as evapotranspiration is projected to increase and decrease in rainfall, thus, they will be wounded by desiccation and shrinkage.

(ii)

Crop Biodiversity Tropical Asia is well known for its richness in biodiversity. Climate change could alter the biodiversity, either increase or decrease certain

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flora and fauna by the increase or decrease in precipitation, temperature or carbon dioxide levels. (iii) Coral Reefs Coral reefs are vital for aquatic organisms as they provide shelter and protections. The event of El-Nino has caused coral reefs to bleech due to oxidation stress. Marine scientists reported that coral reefs are sensitive to prolonged increase in seawater temperature and irradiance. In Indonesia for instance, coral reefs failed to recover from El-Nino event in 1983. (iv) Mangroves Tropical Asia houses to more than 40% of the worldÊs mangroves. Mangroves could also be affected by climate change, particularly temperature increase and rise in sea levels. Both temperature increase and rise of sea levels could bring peril to organisms residing in this area. (b)

Hydrology and Water Resources Water is recognised as an important asset to humans and to all living organisms. With rapid population growth, urbanization, industrialisation and agricultural activities, water resources in Tropical Asia are facing threats ă water pollution and increase in water demand. Scientists believed that climate change will further amplify the demand on water resources. They believe that climate change might bring increase in evaporation, changes in precipitation patterns. These changes may affect runoff, frequency, and intensity of floods and droughts, water for irrigation and hydroelectric generation. Hydrological Systems The change in climate would cause changes in hydrological systems in Tropical Asia. For instance, increase in temperature could increase the rate of snowmelt and reduce the amount of snowfall, in the Himalayas. Downstream of these areas will probably encounter floods and rise in sea levels. Monsoon rains and droughts are common in tropical asia on a seasonal basis. Because of the change in climate, duration of monsoon rains might be altered. For example, monsoon rains could be prolonged and might bring frequent flooding and increase depth of inundation in areas surrounding river basins, and also droughts. During the drought season, the agriculture sector would significantly face insufficient water supply. Besides agriculture, a change in the climate would cause a substantial effect on fisheries, reservoir storage and operation, and industrial and domestic water supply.

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Agriculture, Forestry and Fisheries The effect of climate change on certain agricultural food crop production has been addressed. For instance, the production of some rice varieties were found to be affected by the change of climate. Scientists showed that rice production increases as the carbon dioxide concentration increases. However, increase in temperature will reduce the rice production and this will offset the positive effect. (i)

Fisheries The marine fisheries will be greatly reduced with minor change of the ocean environment (e.g. temperature, salinity, wind speed and direction, ocean currents). Reduction of marine fisheries will be further amplified with the introduction of pollutants. Beside the marine fisheries, the increase of temperature may cause coastal inundation and, this can give negative impact to humans and the coastal ecosystem.

(ii)

Coastal Zone Coastal areas would be severely affected by the climate change on coastal areas. Scientists estimate that a 1 m rise in sea level could displace nearly 15 million people, especially in Vietnam, Myanmar, Thailand and the Philippines. They projected negative impacts including land loss and population displacement, increased flooding, negative impact to agricultural sector due to inundation, saliniation and land loss, coastal aquaculture and coastal tourism.

Human Health Scientists found that climate change can cause a change in the distribution of vector-borne diseases like malaria, dengue and leishmaniasis. The combination of high population densities and poor sanitation, causes waterborne and food-borne infectious diseases to be a threat to Tropical Asia countries. WHO (1996) suggest that climate change would likely affect distribution, life cycle, and population dynamics of dengue. An increase of 3-4ÀC in average temperature may double the reproduction rate of the dengue virus. Figure 4.8 illustrates the critical temperature in malaria epidemiology.

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Figure 4.8: Critical temperatures in malaria epidemiology (ÀC) (WHO, 1996)

SELF-CHECK 4.4 Could the increase of dengue due to global warning?

4.3

SEA LEVEL RISE

Rise of sea levels is caused by the melting of glaciers and thermal expansion of the ocean. Human activities have polluted the environment to the extent of affecting the climate (and also natural phenomenas). The WMO reported that the northern hemisphere sea-ice extent was 5.4 million square kilometres in September 2003, which was nearly as low as the record low of 5.3 million square kilometres in September 2002.

4.3.1

Effects of Sea Level Rise

The rise of sea levels will bring tremendous effect to organisms, both land and ocean. The consequences of sea level rise can be broadly classified into three categories: Ć

shoreline retreat

Ć

temporary flooding

Ć

salt intrusion

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The most serious threat to humans and land organisms would be inundation or permanent flooding of lowlands. The rise of sea levels would also bring: Ć

alter tidal ranges in rivers and bays

Ć

increase the heights of waves

Ć

decrease the amount of light reaching the ocean bottom

Table 4.2 below illustrates the effect of sea level rise. Table 4.2: Effect of Sea Level Rise Effect of Sea Level Rise

Result

Inudation

Conversion of lowlands to wetland, and conversion of wetlands to open water. Rivers, bays and surroundings of riverside will be inudated.

Erosion

Beaches and land will be eroded. Oceans and rivers will be closer to land.

Flooding

Low lying areas will be prone to flooding (may include farther inlands), loss of wetlands, and lack of clean water.

Saltwater intrustion

Saltwater from oceans will advance to inland aquifers and estuaries. This will make land inhabitable even before inudiation.

Extreme weather occurs over a short period of time is capable of harshly affecting humans. Usually, MDCs and LDCs are more vulnerable to climate change than the DCs or richer communities. Figure 4.9 briefly summarizes the impact of climate change. Humans are vulnerable to climate extremes such as storms, droughts and floods. A change in climate would cause the frequency and intensity of such extremes. These changes could cause: Ć

lack of fresh water supplies, unavailability of clean water for daily consumption, contaminated water supplies, and damage of sewage systems which will cause the rise of infectious diseases.

Ć

food production may be affected either directly or indirectly through pests and crop diseases.

Ć

the rise of sea levels or droughts may lead to population displacement, creating environmental refugees and health related problems.

Ć

increase outbreak of diseases

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Figure 4.9 Summary of the impact of climate change

Inundation

Thermosphere

Mesosphere

Troposphere

Stratosphere

Multiple choice questions 1.

Arrange the following layers of the atmosphere from the earthÊs surface. (i) Thermosphere (ii) Stratosphere (iii) Troposphere (iv) Mesosphere A. (i), (ii), (iii) and (iv) B. (iii), (ii), (i) and (iv) C. (iii), (ii), (iv) and (i) D. (iv), (i), (iii) and (ii)

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2.

Which of the following natural chemicals DOES NOT destroy the ozone? A. Methane B. Nitrous oxide C. Water vapour D. Bromine

3.

The following are some effects of climate change EXCEPT: A. Rise in sea levels B. Increase in agriculture production C. Increase of drought D. Increase of rainfall

4.

The change of climate will cause the followings EXCEPT: A. Increase in AIDS patients. B. More lands will be inundated. C. Increase in skin related cancer cases. D. Decrease of planktons.

5.

The followings are the advantages of using CFC in industries EXCEPT: A. it is a stable product B. it is inexpensive to produce C. It is inflammable D. It is flammable

6.

Ozone layer is thickest at the equator. A. True B. False

7.

Why CFC was once considered as a marvellous substance? (i) It is flammable. (ii) It is a stable substance. (iii) It is cheap to produce. A. (i) and (ii) B. (ii) and (iii) C. (i) and (iii) D. (i), (ii) and (iii)

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8.

What is required to form ozone? (i) oxygen (ii) sunlight (iii) hydrogen A. (i) and (ii) B. (ii) and (iii) C. (i) and (iii) D. (i), (ii) and (iii)

9.

Increase in global temperature will (i) cause drought. (ii) deplete glacial. (iii) increase diseases. A. (i) and (ii) B. (ii) and (iii) C. (i) and (iii) D. (i), (ii) and (iii)

10.

Which of the followings is a catalyst in the ozone depletion process? A. Ultraviolet. B. Ozone C. Chlorine. D. CFC.

1.

(a)

List the atmospheric layers from the earthÊs surface

(4 marks)

(b)

State the importance of ozone layer.

(2 marks)

(c)

Why chlorofluorocarbons (CFC) were considered as a marvellous substance?

(4 marks)

(d)

What are the products of CFC degradation.

(3 marks)

(e)

Discuss the process of ozone depletion by using appropriate charts.

(7 marks)

(a)

State the effects of sea level rise.

(8 marks)

(b)

Discuss the impacts of climate change on the following aspects in Asia:

2.

(i)

human health

(ii)

water resources

(iii) agriculture

(12 marks)

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Abarca, J.F, & C.C. Casiccia (2002). Skin cancer and ultraviolet-B radiation under the Antarctic ozone hole: southern Chile, 1987-2000. Photodermatology, Photoimmunology & Photomedicine: 18, 294pp. Fahey, D.W. (2002). Twenty questions and answers about the ozone layer. Intergovernmental Panel on Climate Change (IPCC) (2001). Climate Change 2001: Third Assessment Report (Volume 1). Cambridge: Cambridge University Press. Manins, P., R. Allan, T. Beer, P. Fraser, P. Holper, R. Suppiah, R. & K. Walsh (2001). Atmosphere, Australia State of the Environment Report 2001 (Theme Report). CSIRO Publishing and Heritage, Canberra. Mankin, W., & M. Coffey (1983). Increased stratospheric hydrogen chloride in the El Chichon cloud. Science: 226, 170pp. Mankin, W., M. Coffey, & A. Goldman (1992). Airborne observations of SO2, HCl, and O3 in the stratospheric plume of the Pinatubo volcano in July 1991. Geophys. Res. Lett., 19, 179 pp. McKenzie, R., B. Connor, & G. Bodeker (1999). Increased summertime UV radiation in New Zealand in response to ozone loss. Science: 285, 17091711pp. Titus, J. G. (1986). Greenhouse effect, sea level rise, and coastal zone management. Coastal Zone Management 14(3):147-171pp. Titus, J. G. (1990). Greenhouse Effect, Sea Level Rise, and Land Use. Land Use Policy, Vol 7: issue 2, pp:138-53. World Health Organization (1996). Climate Change and Human Health. McMichael, A.J., A. Haines, R. Slooff, and S. Kovats (eds.). WHO, Geneva, Switzerland, 279 pp. World Meteorological Organization (2004). WMO Statement on the Status of the Global Climate in 2003. WMO-No.966. World Meteorological Organization.

Topic X Environment

5

Management Policy and Regulation

LEARNING OUTCOMES By the end of this topic, you should be able to:

X

1.

Describe the efforts by the Malaysian governmental agencies and non-governmental organizations in combating environmental problems;

2.

Identify the function and important players in Environmental Impact Assessment; and

3.

Identify the roles and objectives of some international cooperations.

INTRODUCTION

Managing the environment is a huge task. Every citizen on earth plays important role in prolonging and sustaining the environment. Malaysia (like other countries) enacted the Environmental Quality Act (1974) to better manage the local environment. Various governmental agencies were established and work together with non-governmental organizations and private sector. Besides managing the environment, these organizations also help to promote and instill awareness about the environment. Along with their own environmental quality act, world nations work together in tackling global environmental problems by signing and ratifying international treaties. By participating in international environmental laws, much pollution can be substantially reduced. Moderate developing countries (MDC) could benefit

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from the transfer of technologies especially green technologies. With the concerted effort from all nations, the earth could be preserved for future generations.

5.1

MALAYSIAN ENVIRONMENTAL LEGISLATION

Malaysia is a fortunate country; safe from earth quakes, tornadoes and hurricanes, extreme temperatures and gifted with abundant natural resources. Malaysia is currently experiencing high economic growth, with various industries and international corporations are established. This places a great demand on land and natural resources, and environmental pollution seems inevitable. The Malaysian Government thus created the Ministry of Natural Resources and Environment, the various government agencies in related to environmental issues and enacted the Environmental Quality Act in 1974 to combat environmental pollution.

5.1.1

Ministry of Science, Technology and Innovations

In view of the impact and seriousness of environmental problems, the Malaysian government formed the Ministry of Science, Research and Local Government in 1973. In line with the changes in science, technology and environment, the ministry was revamped and known as the Ministry of Science, Technology and Environment in 1976. As Malaysia progressed, the Government felt that there was a need to revamp this ministry in order to better reflect its function, hence, since 2004, this ministry was known as the Ministry of Science, Technology and Innovation. The mission of this ministry is „to create a conducive environment for the advancement of science and technology as a means of generating knowledge, wealth and raise the quality of life through sustainable development‰. This ministry is supported by a wide range of government agencies, statutory bodies and non-governmental organizations. Among the agencies and organizations are Malaysian Centre For Remote Sensing, Department of Environment, Department of Chemistry, Malaysian Meteorological Services, Malaysia Institute For Nuclear Technology Research, SIRIM, MIMOS, Malaysia Science Academy, and Malaysian Industry Group and High Technology. Beside the efforts of combating and governing issues pertaining to environment, this ministry also gives research grants and scholarships for Malaysians. The

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research grant given is known as Intensified Research on Priority Areas (IRPA). The IRPA grant is granted to deserving Malaysian researchers to conduct research in areas such as biotechnology, agricultural and other areas. It is hoped that the research from this grant will bring benefit to local and international communities. Scholarships are given for Malaysians to further their studies in specific fields.

5.1.2

Environmental Quality Act 1974

In order to govern the environment problems effectively, the Malaysian Government enacted the Environmental Quality Act (EQA) 1974. This Act incorporates other environmental Acts and regulations due to the complexity of environmental problems. Many countries view the EQA is a comprehensive environmental legislation as it contains specific provisions, namely air pollution, noise pollution, land pollution, inland water pollution, and discharge of wastes into water bodies. To further support and strengthen the EQA, the Environmental Quality Council (EQC) was established in 1977. Members of EQC are from academia, state and federal government officers, industrial and non-governmental organizations. The function of this council is to advise the Minister of Science, Technology and Innovation on matters pertaining to environmental issues and legislation. This council also provide the Ministry with guidance to formulate policies and strategies.

5.1.3

Malaysia Environmental Policy

With all the appropriate legislations and governmental agencies in place, the Malaysian Environmental Policy was formed by the Government in 2002. This policy was created to ensure continuous social, cultural and economic growth. By promoting the use of environmentally friendly products and practising sustainable development, quality of life and life-span of Malaysians will be increased. The objectives of the Environmental Policy are to: Ć

have a clean, safe, healthy and productive environment for present and future generations;

Ć

conserve the rich culture and natural heritage with support of the society; and

Ć

sustain lifestyles of its citizens.

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National Biodiversity Policy SELF-CHECK 5.1

What do you understand of Biodiversity?

The National Biodiversity Policy was formulated by the National Committee on Biodiversity in 1998. This Policy demonstrated MalaysiaÊs commitment in the conservation of biodiversity as Malaysia is a signatory to The Convention on Biological Diversity at the Earth Summit in Brazil in 1992.

Search in the Internet for the objectives of The Convention on Biological Diversity.

The vision of the National Biodiversity Policy is „to transform Malaysia into an international centre of excellence in conservation, research and utilisation of tropical biodiversity by the year 2020.‰ Its policy statement is „to conserve MalaysiaÊs biological diversity and to ensure that its components are utilised in a sustainable manner for the continued progress and socio-economic development of the nation.‰ In simple words, this policy is focussed on conservation of natural ecosystems (cycling of nutrients, air and water), biological resources (diversity of plants and animals) and traditional cultures for future generations. This policy is expected to have positive impacts in the following areas: (i)

Economic Benefits

(ii)

Food Security

(iii) Environmental Stability (iv) National Biological Heritage (v)

Scientific, Educational and Recreational Values

(vi) Biosafety

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ENVIRONMENTAL IMPACT ASSESSMENT

The Environmental Impact Assessment (EIA) is an environmental tool designed to evaluate proposed projects, provides prediction and information of potential environmental impacts and benefits to local residents and environment. The EIA functions as a filter system which filters-out projects that will harm to the environment and local residents. The EIA also functions as a planning tool for the government ă preventing projects that have the potential of incurring higher cost ă during or after their completion. The EIA covers both new and development of existing projects. The EIA is governed by section 34A of the Environmental Quality Act 1974. Through the stringent EIA procedure, project proponents can gain benefits whereby they could choose to withdraw or modify their proposed projects as the EIA is scrutinized by a group of experts. Thus, organizations can reduce their loss by rectifying, modifying or stopping their proposed project. The EIA procedure requires organizations to state the need of such project, and the benefits to the community and environment.

5.2.1

Important Players in the EIA

(a)

Initiator The initiator is the person or organization (including government agencies) that proposes a project development or improving the present infrastructure. The initiator must state the need of such a project to be developed and its benefits to the environment and to the communities. The initiator is usually the body that is responsible for the planning of the project development and bears the cost of it.

(b)

Assessor The assessor is the person or organization which is responsible for conducting the EIA and is answerable to the Initiator. The assessor can be considered as the team responsible to carrying out the initiator Ês project.

(c)

General Public The involvement of the general public is crucial in the EIA procedure. Without public participation, a project development will be suspended or halted indefinitely. The public is crucial because they would know best the needs of local residents and identify potential impacts. Copies of the EIA report will be displayed in Department of Environment (DOE) offices, public libraries and offices of relevant local authorities.

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For example, in the Broga incinerator project, the concerns from local residents has made the Department of Environment re-evaluate and has decided to reallocate it. (d)

Panel of Experts A panel of experts is appointed to provide scientific, technical and economic advice to local authority. The panel may consist of experts from government agencies, public universities, non-governmental groups and private sectors. These specialists will scrutinize the proposed project development, and provide inputs on the impacts and effects to the environment.

5.2.2

Approval of the EIA Report

The following government agencies are granted the authority to review the proposed project, whether to accept or reject it. (i)

National Development Planning Government sponsored projects.

Committee

(NDPC)

for

Federal

(ii)

State Executive Council (EXCO) for State Government sponsored projects.

(iii) Local Authorities or Regional Development Authorities (RDA) ă within their area (iv) Ministry of International Trade and Industry (MIDA) for industrial projects.

SELF-CHECK 5.2 Can the mass media influence the decision of authorities of a certain project development? Provide an example and discuss it in your forum.

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ENVIRONMENTAL PROGRAMMES BY THE MALAYSIAN GOVERNMENT Recycling SELF-CHECK 5.3

Do you know what this symbol

means?

Recycling is the process of reusing unwanted things or products. Recycling also includes giving other people to reuse the unwanted materials. By using recycling, the lifespan of products or unwanted materials would be prolonged. By prolonging the usage of products, reduction of products will occur. Hence, the 3R method ă Reduce, Recycle and Reuse was created. To increase the awareness among Malaysians, the Malaysian government has declared that 11 November as the National Recycling Day (Figure 5.1). A nationwide recycling programme was launched by Malaysian Government in 2001. This project which involves many parties ă city councils, schools, nongovernmental organizations, concessionary companies, recyclable waste collectors, recyclers associations, residence associations and private organizations. This project also utilized the mass media to educate the public about recycling activities. In this programme, recycling bins (Figure 5.2) for different type of wastes are being placed in strategic locations.

Figure 5.1: Logo of National Recycling Day

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Figure 5.2: Recycling bins

SELF-CHECK 5.4 The 3Rs: Reduce, Reuse and Recycle, which is the most important? Why?

5.3.2

National CFC Phase-Out Plan

Tackling environmental problems is a huge and difficult task, and it requires commitment from all citizens of the earth. Every country has their own environmental laws and faces different type of environmental problems. As mentioned earlier, pollutantsÊ moves easily between nearby countries and/or far away countries. To counter transboundary movement of pollutants, global environmental conventions and protocols were launched. However, in the implementation of these conventions and protocols, some exceptions were given to poor and developing countries. Malaysia, though a developing country, is serious about protecting her fragile environment. This is reflected by the signing and/or ratification of certain global environmental conventions and protocols.

SELF-CHECK 5.5 What are the conventions and protocols that Malaysia ratified?

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Considering the importance and benefits of the ozone layer, Malaysia ratified the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol on Substances that Deplete the Ozone Layer on 29 August 1989. In the following year, Malaysia ratified the London Amendment and in 1992, ratified the Copenhagen Amendment. Countries that ratify the Convention are required to comply with its legislation ă reduction of consumption, phasing out and substitutes of ozone depleting substances in a given time frame. Targets of reducing the consumption of these chemicals must be met. Under the Montreal Protocol, Malaysia is required to reduce consumption of ozone depleting substances and total phase-out of ozone depleting substances listed in 2010.

5.4

EFFORTS OF NGOS AND PRIVATE ORGINIZATIONS IN COMBATING ENVIRONMENTAL PROBLEMS

In viewing the importance of protecting our fragile environment, the Malaysian government has established several government agencies and employed some methods to deal with such matters. To achieve the objectives, private organizations, non-governmental organizations (NGO) also play an important role. Below are some highlights of NGOs and private organizations in protecting the environment.

5.4.1

Malaysian Nature Society

The Malaysian Nature Society (MNS) was established in 1940. MNS is one of the most active NGOs in Malaysia. The MNS mission is „to promote the study, appreciation, conservation and protection of MalaysiaÊs Natural Heritage, focusing on biological diversity and sustainable development‰. MNS works closely with various governmental agencies, universities, institutions, mass media and private organizations in conservation of the MalaysiaÊs biodiversity and the natural environment. One of the most notable contributions of MNS is the establishment of Nature Club in Malaysian schools and Nature Education Center. The Nature Club was launched in 1991 with funding and support from the Ministry of Education and private organizations. This project aimed to create care and understanding of the environment, and instilling environmental awareness among school children. The Nature Education Center was launched in 1993 to raise awareness of nature and its influence in our life. This project was a special project as it involve both government and private sector (FRIM-MNS-SHELL).

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How do you participate in MNSÊs activities? Visit MNSÊs web site at www.mns.org.my to find out.

5.4.2

Sahabat Alam Malaysia (SAM)

Sahabat Alam Malaysia (SAM) or Friends of the Earth, Malaysia was established in 1977. SAM is a community based NGO that deals with Malaysian environmental and development issues, and indigenous communities. The objectives of SAM is to educate the public pertaining to the environment, assist communities affected by development, and supporting any programmes or projects that are environmental and community friendly. Among the concerns of SAM is the impact of Bakun dam to local communities. SAM assists local communities in airing their concerns of their livelihoods to relevant authorities. The proposal of building a second Penang bridge is also one of the concerns of SAM. In this issue, SAM highlighted several concerns such as air pollution, noise pollution, water pollution and also suggested alternatives of overcoming congestion on the Penang bridge.

Find out other concerns of SAM at www.foe-malaysia.org. Would you support their activities. Discuss it in your forum.

5.4.3

Centre for Environment, Development, Malaysia

Technology

and

Centre for Environment, Technology and Development, Malaysia (CETDEM) was established in 1985. It is a NGO that conducts research, consultancy, and training related to the environment. Among the environmental issues focussed are the impacts of climate change, sustainable energy, sustainable transport, sustainable agriculture and sustainable development. CETDEM is currently involved in raising awareness and building the capacity of urban Malaysians on sustainable energy options. This project is funded by the UNDP/Global Environmental Facility and is viewed as a continuation of the previous project ă Public Awareness on Energy Efficiency and Renewable Energy

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in 1999. The objective of this project was to establish awareness among Malaysians about the importance of sustainable energy and to reduce dependency on fossil fuels. By reducing fossil fuel consumption, greenhouse gases will be reduced. This project also hopes to educate Malaysians on the adverse impacts of climate change and non-renewable energies.

How do you participate in CETDEMÊs activities? Visit CETDEMÊs web site at www.cetdem.org.my to find out.

EXERCISE 5.1 Name two environmental NGO in Malaysia besides the above?

5.5

INTERNATIONAL COOPERATIONS

International conventions were formed to tackle environmental problems globally. International convention is a term used for formal multilateral treaties between a several numbers of countries under an International Organization. Within the international conventions, supplementary provisions are usually incorporated. Supplementary provision are known as protocols.

5.5.1

Convention on Climate Change

Numerous intergovernmental conferences were held between 1980s and 1990s to combat global warming. In 1992, UN Framework Convention on Climate Change (UNFCCC) was established. This convention was signed in Rio de Janeiro. The UNFCCC was the largest gathering of Government Heads since the 1972 Stockholm Declaration.

Search in the Internet for information about Stockholm Declaration.

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The main objective of this Convention was the „stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic (human-induced) interference with the climate system‰. The Convention entered into force on 21 March 1994 and the Conference of the Parties (COP) is the authority of this Convention. Countries that have ratified the Convention will meet annually to foster and monitor its implementation and discuss about the best practises to tackle climate change. Ratification of a convention requires approval and consent of a countryÊs parliament or government. (a)

Commitments Countries that have ratified the convention agree to compile an inventory of their greenhouse gas emissions and submit a „national communications‰ report to the Convention. Besides this, all countries are required to prepare national programmes containing: Ć

strategies for mitigating climate change and adapting to its impact.

Ć

methods to promote technology transfer and development, especially green technologies

Ć

the regulation and sustaining carbon sinks

Ć

information exchange and sharing, and promoting climate research

Ć

programmes related to climate change such as in education, training and raising public awareness

Industrialised and „rich‰ countries have several specific commitments and responsibilities. Among their obligations are to: Ć

implement policies and methods of returning their greenhouse gas emissions to 1990 levels

Ć

provide financial resources to developing countries, international NGOs or other organizations that deals with this matter.

Ć

facilitate technology transfer to developing countries

Ć

funding the costs for developing countries for submitting their national communications

SELF-CHECK 5.6 Why HDCs and „rich‰ countries are given a heavier task than MDCs and LDCs?

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(b)

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The Kyoto Protocol More than 10000 delegates, observers and journalists participated in the third COP in Kyoto, Japan in December 1997. The objective of the COP meeting was to address the problems of climate change and reduce greenhouse gas emissions. A consensus was reached and the Kyoto Protocol was adopted. The Kyoto Protocol concentrates on the emissions trading system, the Clean Development Mechanism, emissions reductions from carbon sinks and the compliances. The Protocol pledges to accelerate the UNFCCCÊs ultimate objective ă preventing „dangerous anthropogenic interference with the climate system‰.

SELF-CHECK 5.7 Why do you think the United States of America do not ratify the Kyoto Protocol? In this Protocol, 38 industrialised countries commit to reduce or cut greenhouse gas emissions to 5.2% below the 1990 levels by 2008-2012. Developing countries such as China and India were requested to set their targets for greenhouse gas emissions voluntarily. The Kyoto ProtocolÊs rules focus on: Ć

Commitments: emissions targets and general commitments

Ć

Implementation: methods to be conducted and implementing mechanisms

Ć

Minimizing impacts on developing countries

Ć

Accounting, reporting and review

Ć

Compliance

The Kyoto Protocol states that: Ć

developed countries are to reduce their emissions of six key greenhouse gases by at least 50%.

Ć

reduce the use of fossil fuel and promotes the use of renewable energies

Ć

emissions target must be achieved by 2008 ă 2012

Ć

„demonstrable progress‰ must be made by 2005

Ć

reduction of carbon dioxide, methane and nitrous oxide level against a base year of 1990 (except developing countries)

Ć

reduction of industrial gases ă hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride (measured against either 1990 or 1995)

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SELF-CHECK 5.8 What is renewable energy? Besides the emissions targets, the Kyoto Protocol also stresses on general commitments which includes: Ć

improving the quality of emissions data

Ć

increase national mitigation and adaptation programmes

Ć

increase transferring of environmental friendly technologies

Ć

collaborative scientific research and climate observation networks

Ć

provisions for education, training, public awareness programmes

Ć

supporting capacity building initiatives.

However, countries are given a certain degree of flexibility on how they produce and reduce emissions. In addition, „clean development mechanisms‰ will be developed so that developed countries are able to finance developing countries in emissions-reduction projects.

Find out what is emission trading from the internet. Discuss it in your forum.

5.5.2

Vienna Convention

In 1985, head of governments met in Vienna, and the Convention for the Protection of the Ozone layer was born. Nations agreed to use appropriate measures and methods to protect human health and the environment against the harmful effects caused by human activities or natural phenomena. About 20 nations signed this Convention but did not ratify it. (a)

Objectives of the Vienna Convention The objectives of the Vienna Convention are to cooperate in research with regards to the ozone layer, alternative substances, develop technologies and monitoring of the ozone layer. The Convention also emphasizes the cooperation of formulation and implementation of controlling activities that can alter the ozone layer and formulating appropriate protocols. Besides cooperation from nations, the exchange of scientific, technical, socioeconomic, commercial and legal information, and development and

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transferring of technology and knowledge to other nations are also emphasized. (b)

Montreal Protocol After the Vienna Convention, world leaders met and discussed on environmental issues and the Montreal Protocol on substances that deplete the ozone layer was established. The Protocol came into force on 1st January 1989 and required industrialised countries to reduce their consumption of chemicals which could bring damage to the ozone layer. Industrialied countries are required to phase-out the production and consumption of CFCs, halons and other ozone depleting chemicals in a specific schedule. However, developing countries are granted special provisions whereby they are given a grace period to phase-out these substances. They are given special provisions because their production and usage of these substances are relatively small and their economies are in the developing state. Most MDCs agreed to reduce or stop consumption of most CFCs based on 1995-1997 averages, beginning 1 July 1999. They also agreed to further reduce the consumption by 50% by 1st January 2005 and by 1st January 2010, the use of CFCs will be abolished. Besides this, the Montreal Protocol also introduces other kinds of control measures and to add new controlled substances to the list. This Protocol was ratified by only 29 countries in 1989. Through many scientific evidences, the number of countries that ratifies this Protocol increased to 184 in the 2003. Scientists predicted that the recovery of the ozone layer is expected to occur approximately by 2050 if all countries are committed to comply with the Montreal Protocol and its amendments.

Below are some amendments of the Montreal Protocol (i)

London Amendment The London Amendment was made to include some CFCs which are not included in the Montreal Protocol. The Amendment included the control of production and consumption of other halogenated CFCs, carbon tetrachloride and methyl chloroform. Trade restriction on some CFCs was introduced. To aid and enable MDCs to comply with the Protocol, a financial mechanism was introduced. This financial mechanism aims to provide financial aid and also technical support to MDCs.

(ii)

Montreal Amendment The Montreal Amendment introduced the requirement for licensing systems. This licensing system will better manage and monitor the trade of substances under this Protocol.

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(iii) Beijing Amendment The Beijing Amendment introduced the control measures for production for HCFCs. This Admendment imposed trade restriction for HCFCs. Trade restriction for production and consumption of bromochloromethane (BCM) was also introduced.

5.5.3

Basel Convention

In the late 1980s, a stringent environmental regulation in HDCs caused a rise in the cost of hazardous waste disposal. This forced some unscrupulous industries to illegally export hazardous wastes to MDCs and LDCs. With the enactment of The Basel Convention, illegal dispose of hazardous waste was prohibited. In the initial stage (1989-1999), the ConventionÊs primary function is to set-up a framework for controlling transboundary (international) movements of hazardous wastes.

Objectives of the Basel Convention The ultimate objective of the Basel Convention is to develop criteria for Environmentally Sound Management (ESM) of hazardous waste disposal. The purpose of ESM is to protect human and the environment by reducing hazardous waste production. The ESM tackles hazardous wastes by using an „integrated life-cycle approach‰. In this integrated approach, stringent control are employed from the generation of wastes (including hazardous) to storage, transport, treatment, reuse, recycling, recovery and final disposal. The other objectives of the Basel Convention are (i) to minimize the generation of hazardous wastes, whether quantity or hazardousness (ii) the disposal of hazardous waste close to the source of generation (iii) to reduce movements of hazardous wastes. Hazardous wastes included in this Convention are termed toxic, poisonous, explosive, corrosive, flammable, ecotoxic and infectious substances.

SELF-CHECK 5.10 Why hazardous wastes should be dealt as close to the source? Transboundary or movements of hazardous wastes (including other wastes) are prohibited under this Convention. However, movements are allowed with

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written notification to the importing and exporting authorities. Movements of hazardous wastes must be accompanied with proper documentation. Although movements of hazardous wastes are permitted with proper documentations, it must be further supported by evidence of the inability of the exporting country to manage or dispose of it. There are also some countries that prohibit the export of hazardous wastes. The Basel Convention defines that illegal transboundary movement of hazardous wastes occurs under these conditions: Ć

without notification pursuant to the provisions of the Convention

Ć

without the consent from the Convention

Ć

falsification and mispresentation of documents or fraud

Ć

when movement does not conform with the documents

Ć

when movement results in deliberate disposal of hazardous waste

5.6 5.6.1

ALTERNATIVE METHODS TO SUSTAIN THE ENVIRONMENT Green Vehicle

The numbers of vehicles are increasing from year to year. More vehicles can be translated into higher demand for hydrocarbon fuels, and this means that more pollutants are released into the atmosphere. The use of liquefied petroleum gas (LPG) is currently being used in public transportation. The LPG is considered as green gas because vehicles using LPG emits less of CO2 , NOx, hydrocarbons and carbon monoxide compared to petrol and diesel vehicles. Currently, some taxis in Malaysia are already using LPG vehicles. Various companies are currently conducting research on electric hybrid cars.

5.6.2

Government Incentives

Governments play an important role in promoting the development and use of green technologies. Through some fiscal and tax policies, the use of green technologies can be expedited. Along with green technologies, proper planning and development of new housing and commercial areas, and sustaining natural heritage and green lungs can also aid the Earth.

TOPIC 5

5.6.3

ENVIRONMENT MANAGEMENT POLICE AND REGULATION

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Carbon Sinks

Carbon is stored in many places ă oceans, forests, plants, wetlands, soils, etc. The carbon sink is defined as any natural ecosystems that can absorb carbon from the atmosphere. All natural ecosystems have the ability to absorb carbon, but under the Kyoto Protocol, forests are the best tool to absorb carbon. Beside forests, carbon can also be absorbed in agricultural soils, which can improve soil productivity, prevent erosion, and increase agricultural products.

Managing the environment is a challenging but not an impossible task. In the local scenario, NGOs, governmental agencies and private organizations are working hand-in-hand to develop programmes to educate the public on this matter. The Malaysian government has laid out specific guidelines to better manage the environment ă Environmental Quality Act, 1974 and Environmental Impact Assessment. In the international scenario, nations work together and formed several conventions and protocols to better protect and manage the environment. Among the notable ones are United Nations Convention on Climate Change, Vienna Convention and the Basel Convention.

Carbon sink

Protocol

Convention

Ratification

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Multiple Choice Questions A.

i and ii

B.

ii and iii

C.

i and iii

D.

i, ii and iii

1.

The NGOs that deal with environmental issues include (i) WWF. (ii) SAM. (iii) UNESCO.

2.

Amendments of the Montreal Protocol includes: (i) Montreal Amendments. (ii) China Amendments. (iii) London Amendments.

3.

Why Basel Convention was enacted? (i) To enable countries to dispose their hazardous wastes. (ii) To control import and export of hazardous wastes. (iii) To treat hazardous wastes near to its source.

4.

The objectives of the Malaysia Environmental Policy are: (i) To have a clean, safe, healthy and productive environment. (ii) To sustain the lifestyles of Malaysians. (iii) To conserve cultural and natural heritage.

5.

How can you help to prevent further environmental degradation? (i) By using green products. (ii) By planting more trees. (iii) By upgrading your academic qualification.

6.

Company AAA plans to upgrade its waste treatment facility in town BBB. What should the company do? (i) Submit EIA report. (ii) Seek approval from local authorities. (iii) State the reason of the upgrade through mass media.

7.

What are the common commitments of countries ratifying UNFCC, Vienna and Basel Convention? (i) Provide financial support to moderately and least developing countries with regards to environmental issues. (ii) Assist in increasing awareness of environmental issues. (iii) Information sharing concerning environmental.

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8.

Which of the followings is FALSE the Basel Convention? (a) Reduce wastes production (b) Prevent movements of wastes (c) Dispose wastes at the source (d) Prevent export of wastes

9.

The international agreement on controlling and phasing-out substances that deplete the ozone layer is known as: (a) Stockholm Convention. (b) Vienna Convention. (c) Kyoto Protocol. (d) Beijing Amendment.

10.

Which of the following parties have the authority of the Convention of Climate Change? (a) United Nations (b) ASEAN (c) Conference of Parties (d) G7 countries

1.

(a) (b) (c) (d)

2.

(a) (b) (c) (d)

3.

(a) (b) (c) (d)

What is the function of the Environmental Impact Assessment (EIA)? Name the authorities that evaluate EIA proposals. Discuss the role of important players in the EIA. Why EIA is important? Discuss briefly the benefits of recycling and cite relevant examples of it. Give TWO (2) programmes by the Malaysian societies with regards to environmental protection. State the objectives of the Basel Convention. Why wastes should be dealt close to its source? Define the word „convention‰ and „ratify‰ What is greenhouse gas? Name TWO (2) examples of greenhouse gases Name the convention that focus on stabilization of greenhouse gas concentration. Discuss the benefits of ratifying this Convention.

(2 marks) (4 marks) (10 marks) (4 marks)

(10 marks) (2 marks) (6 marks) (2 marks) (4 marks) (4 marks). (2 marks) (10 marks)

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A

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Handbook of Environmental Impact Assessment Guidelines (2000). Department of Environment, Ministry of Science, Technology and the Environment, Malaysia.

Caring for climate: a guide to the climate change convention and the Kyoto Protocol (2003). UNFCCC. Centre for Environment, Technology http://www.cetdem.org.my

and

Development,

Malaysia.

Climate Change: Information Kit (2002). UNEP and UNFCCC Department of Environment Malaysia and The World Bank. Government of Malaysia. Department of Environment. http://www.jas.sains.my Friends of the Earth, Malaysia. http://www.foe-malaysia.org Kitar semula. http://www.kitarsemula.com Malaysia National CFC Phaseout Plan 2002-2010 (2003). Ozone Protection Section Malaysia Nature Society. http://www.mns.org.my Ministry of Science, Technology http://www.mosti.gov.my

and

Innovation,

Malaysia.

Montreal Protocol Unit. http://www.undp.org/montrealprotocol The Basel Convention. http://www.basel.int The Kyoto Protocol: What just is in it (2003). Environmental Factsheet No. 12. Acid Rain. http://www.acidrain.org The Vienna Convention for the Protection of the Ozone Layer (2001). The Vienna Convention for the Protection of the Ozone Layer and The Montreal Protocol on Substances that Deplete the Ozone Layer. United Nations Environment Programme. http://www.unep.org/ozone

Topic X Water Pollution

6

and Water Treatment

LEARNING OUTCOMES By the end of this topic, you should be able to:

X

1.

Explain how much fresh water is available to us;

2.

Describe major types of water pollution and their sources;

3.

Explain harmful effects of water pollutants to human health and aquatic life;

4.

Describe the self-purification process of water system;

5.

Explain what is euthrophication and principal sources of the process;

6.

Calculate the BOD value;

7.

Explain why O2 gas solubility decreases as water temperature increases; and

8.

Describe physical and biological processes involved in water and sewage treatment.

INTRODUCTION

This topic contains two parts. The first part discusses the chemistry of water pollution. In this part we will discuss about the sources, reactions, effects and fates of the major water pollutants that have greater impact to environment. The degree to which different water bodies are contaminated with several different pollutants depends on many parameters. For example, lakes are considered to be more susceptible to pollution than rivers. Rivers are much easier to eliminate the pollutants compared to the lakes. This is because the flowing rivers can rapidly purge themselves of pollutants if the source of the pollution is not constant. However, polluted lakes may take between 10 and 100 years to be replaced.

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In the second part of this topic we will learn about water and sewage treatment. Water supplies for domestic and commercial uses are treated to ensure the waters are free from pathogens and to eliminate odors and turbidity. Waste water or sewage was treated to reduce water pollution and euthrophication. The principal of municipal water treatment which commonly apply in the treatment plant will be discussed. The chemistry involved in the processes will be pointed out.

6.1

CHEMISTRY OF WATER POLLUTION SELF-CHECK 6.1

Is our tap water safe for drinking? What are the parameters used to test the quality of water? Do you know how to treat water to make it safe for human consumption?

Water is very important to all living things. The biochemical reactions of living cells take place in aqueous solution. The uniqueness of water as universal solvent has been discussed in topic 4. Our lives depend absolutely on a supply of clean fresh water. Although water is abundant on the EarthÊs surface, about 97 % of EarthÊs supply is in the ocean which is too salty to be used by humans and other living organisms. Only small portion (less than 1 % of total EarthÊs composition) is available as fresh water.

Figure 6.1: Distribution of water on Earth

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Nowadays, the concern about water safety has been arisen due to the presence of potential hazardous chemicals in our drinking water. Industrial and intensive agricultural activities have contributed to the existence of industrial wastes and residue pesticides in the water bodies. According to Organisation of Economic Cooperation and The Royal Commission on Environmental Pollution, pollution is defined as the introduction by man, directly or indirectly, of substances or energy into the environment resulting in deleterious effects of such nature as to endanger human health, harm living resources or interfere with amenities or other legitimate use of the environment. Like air pollutants, water pollutants come from numerous natural and antropogenic sources. Water pollution is a global problem which does not respect to boundaries. Pollutants produced in one country often end up in another countryÊs water supply. Movements of pollutants from one medium (such as air) to another medium (such as water) is called cross-media contamination, This indirect process of contamination is more concerned by scientist in recent years. For examples, pesticides sprayed on crops may drift to nearby rivers and lakes, and then flow into the ocean (see Figure 6.2). Water pollution can occur through natural processes. For example, natural soil erosion will produce sediments during rainy day. This is because rainwater is naturally acidic (pH 5.6 ă 7.0) which can cause soil erosion. Nevertheless, in this topic the discussion of water pollution is referred to anthropogenic (man-made) sources of pollutants. The main antropogenic sources of water pollutants are domestic, agricultural or industrial activities. In less-developed countries, the main water pollutants are human and animal wastes, and sediment from agricultural and forestry activities. In more-developed countries, urban run-off and industrial wastes such as toxic metals, organic chemicals and heats are the main water pollutants. Sources of pollution can be divided into two types; point sources and nonpoint sources. Point sources of pollution are factories and commercial building that release toxic substances into the water bodies. In most developed countries, toxic substances released from point sources have been substantially reduced. Most of large factories and industries have their own waste water treatment plants. So, in Malaysia for example, the effluent from industries must be well treated and should be complied with the effluent standard set up by Malaysian Depatment of Environment, before discharging it into the drains or water courses.

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Organic Oxygen-demanding Wastes

The discharge of large quantities of oxygen-demanding wastes such as organic wastes into the water bodies normally has detrimental effects on the flora and fauna. Domestic sewage is the main source of organic waste released into the water. Other sources are run-off from urban areas and farms, and some industrial seffluents particularly from food-processing, textiles and paper-mills. The discharge of animal wastes from livestock farms into the water bodies also can reduce the dissolved oxygen content in the waters and upsetting the biological balance of surface waters. The problem becomes worse when waterborne pathogens present in the water from the animal faeces. This lead to the spread of diseases such as cholera, typoid and hepatitis A.

Figure 6.2: The release of organic wastes from a sewage treatment plant causes the bacterial population to flourish

As they increase, oxygen level decline, causing troubles for fish and other organisms. Note that oxygen levels and fish polulations return to normal in the stream, thanks both to naturally occurring bacteria that decompose the organic matter in the sewage and to the water flow. Organic wastes contain mostly carbohydrates, fats, and proteins. The organic wastes provide rich substance for bacteria. The decomposition of organic matters by aerobic (oxygen-consuming) bacteria deplete the amount of dissolved oxygen in water. Biochemical oxygen demand (BOD), chemical oxygen demand (COD), and Total Organic Carbon (TOC) are parameters used to measure the oxygendepleting capacity of certain amount of organic matter.

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In certain case when river is extremely polluted with oxygen-demanding wastes, the bacteria use up all oxygen available in the water. At this stage, fish will die because they are unable to survive. Then, anaerobic bacteria replace to decompose the organic matter. During this decomposition process, hydrogen sulfide (H2S) and ammonia (NH3), toxic gases are released which give foulsmelling. In addition to the depletion of oxygen content in water, an increase in turbidity and reduction of light available for photosynthesis are other adverse effects of adding oxygen-demanding waste into the river. Eventually, when the water flows downstream the amount of organic waste decreases and the level of dissolved oxygen increases. Then, flora and fauna can re-establish again. The process of decomposition of organic effluents by bacteria is known as self-purification (see Figure 6.2). There are several factors that influence the rapidity and effectiveness of selfpurification process. They are explained in Table 6.1. Table 6.1: Factors that influence the rapidity and effectiveness of self-purification process

Factors that Influence the Rapidity and Effectiveness of Self-purification Process 1.

The rate of water flow (lakes usually much more slowly than rivers in selfpurification process).

2.

The volume of water carried (during hot seasons, stream flow is slow and organic pollutant concentrations are high).

3.

The amount of organic water discharge into the water bodies (when organic input exceeds the ability of aquatic system to restore condition through bacterial decomposition and water flow ă recovery may be impossible).

4.

The temperature of water bodies (an increase in water temperature speed up bacterial decay).

5.

The type of organic wastes. Sometimes, the organic wastes contain other pollutants such as detergent, ammonia and toxic metals.

The best approach to control the water pollution caused by oxygen-demanding waste is to minimise the amount discharged into the water courses through sewage treatment. Such control is easier to enforce compared to nonpoint sources.

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BOD and COD The solubility of oxygen in water at equilibrium with the atmosphere at 25ÀC is 8.7 mgL-1, and less at high temperature. In other words, the oxygen content in water decreases as the water temperature increases. There are several factors which can cause the depletion of dissolved oxygen in water: 1.

Decomposition of biomass (such as alga bloom).

2.

The presence of oxidizable pollutants (from sewage, industrial effluents, and agricultural run-off) in the water bodies.

Biochemical (or Biological) oxygen demand (BOD) is a parameter used to measure the degree of oxygen depletion of water (largely from bacterial decay) due to the presence of biodegradable organic pollutants. The value of BOD gives an indication of how much organic matter is in water. In other word, BOD is an amount of O2 (in unit milligram) required to carry out oxidation of organic carbon in one litre of water. We can calculate the BOD value using the equation below. CH2O + O2 U CO2 + H2O

(6.1)

Values for various industrial wastes and municipal sewage are given in Table 6.2. Table 6.2: Typical BOD values for various processes

Another parameter used in Water Quality Index is Chemical Oxygen Demand (COD), which is determined by using the powerful oxidizing agent, dichromate (Cr2O72-), to oxidize organic matter via the following reaction.

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2 Cr2O72- + 3CH2O + 16H+ U 4Cr3+ + 3CO2 + 11H2O

(6.2)

Excess added dicromate after the oxidation reaction (6.2) is titrated with ion Fe2+ using back-titration method. 2 Cr2O72- + 6Fe2+ + 14H+ U 2Cr3+ + 6Fe3+ + 7H2O

(6.3)

As Cr2O72- oxidizes substances not oxidized by O2, the COD value is usually greater than the BOD, and to some extent overestimates about the oxygen content in waters. Example 6.1 Calculate the BOD of water in which 20 mg of sugar (empirical formula CH2O) is dissolved in 1 liter water sample. Solution:

CH2O + O2 U CO2 + H2O

Step 1: Calculate moles of sugar and O2. Since each mole of CH2O (sugar) requires one mole of O2 (above equation), 1 mole CH2O ≡ 1 mole O2 we divide 20 mg by the molecule weight of CH2O (30 g mol-1) to obtain the required moles of O2. mole of CH2O = mole of O2 =

20 ï×10-3 g = 6.7 × 10-4 mole 30 g mol -1

Step 2: Calculate mass of dissolved O2 (in unit milligram) mass of O2 = 6.7 × 10-4 × 32 g mol-1 = 21.4 × 10-3 g = 21.4 mg O2. ∴ BOD = 21.4 mg/L because volume of water sample is 1.0 L

6.1.2

Toxic Metals

Toxic metals or inorganic water pollutants originate from a variety of antropogenic sources such as industrial discharge, urban run-off, sewage effluents, and mining. Toxic metals include mercury (Hg), lead (Pb), cadminum (Cd), zinc (Zn), and tin (Sn). Among these pollutants, mercury and lead are the major water pollutants. Their toxicity depend on their chemical forms (i.e. their speciation).

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The uptake of these metals can be directly from the water by aquatic organisms in certain chemical forms. The metallic elements then accumulate in certain organs or tissues of these organisms such as fish. An increase of toxic metal concentration in each trophic level of food chain is known as process of biomagnification. When contaminated fish is taken by humans through the food chain, then humans are also at risk of consuming contaminated fish. (a)

Mercury is one of the most toxic inorganic pollutants, primarily exerting its effect through the nervous systems. Mercury is a cumulative poison and can be fatal. The accident in the fishing village of Minamata in Japan (in the 1950s) is an example of the fatalities and severe death problems related to mercury discharge into water bodies. Residents who ate seafood from Minamata Bay, which contaminated with methyl mercury, developed numbness of the limbs, lips and tongue. They suffered lost of muscle control and other neurological effects. Of 52 reported cases, 17 died and 23 were permanently disabled. Inorganic mercury itself is not very toxic. But, once it released into the environment, bacterial action can cause methylation. Therefore, in streams and lakes, dimethyl mercury and monomethyl mercury are two organic forms of mercury compounds produced through this natural process. microorganisms microorganisms Hg 2+ ⎯⎯⎯⎯⎯→ CH 3 Hg + ⎯⎯⎯⎯⎯→ ( CH3 )2 Hg

monomethyl mercury (soluble in water)

dimethyl mercury (insoluble in water, volatile)

Dimethyl mercury can easily evaporate from the water. However, methyl mercury is soluble in water and very toxic. Methyl mercury is slowly released into the water and remains in the bottom sediments, where it enters organisms through the food chain, via the biomagnification process. Methyl mercury is able to disrupt the blood-brain barrier. It acts as a neurotoxin and causes severe behavioural disturbances in affected humans. (b)

Lead In modern society, lead is found in many products such as ceramic glazes, batteries, solder and pipe. Once lead has been used as an additive in petrol for so long before unleaded petrol is introduced as an alternative fuel for motor vehicles. Therefore, the rapid rise in the number of motor vehicles in urban areas has increased the concentration of lead in the environment. Although lead is one of the most useful metals, it is also a highly toxic poison. Unlike cadmium, lead is not taken up actively by plants. It enters human body in inhalation and ingestion of contaminated food and water. It is because lead is abundant in dust and be deposited on food crops, or food

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as it is being processed. High-level exposure of lead can cause neurological symptoms such as fatigue, headache, muscular tremor, clumsiness and loss of memory. Children are particularly at risk and can suffer hyperactivity, lowered IQ and brain damage. Lead is found mostly in the form of tetraalkyl lead compounds (organic lead). Studies show that about 75% of lead emission in the atmosphere is from the exhaust fumes. In adition to the dispersion of lead as fine particle in the atmosphere, lead also may pollute water bodies from industries, for examples in paintworks, and from lead mines.

6.1.3

Organochlorine

Chlorine gas is commonly used in water treatment to kill harmful organisms. Unfortunately, it can also react with organic compounds to form chlorinated organic substances (organochlorines) which are toxic to humans and organisms. Figure 6.3(a) shows the structures of DDT while Figure 6.3(b) shows the structure of PCBs.

Figure 6.3: Structures of (a) DDT and (b) PCBs

(a)

Organochlorine Pesticides

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Manufactured organochlorines have been used as pesticides. These include DDT (dichlorodiphenyltrichloroethane), and PCBs (polychlorinated biphenyls). These compounds are persistent pollutants which are chemically stable and degrades only slowly under environmental conditions. Their solubility are low in water. And, they are lipophilic (fatsoluble). They can accumulate in certain organs and tissues of humans and other organisms through the food chains and food webs, known as biomagnification. Contamination of organochlorines in aquatic ecosystems are primarily from direct application and also from industrial effluents, and agricultural runoff. The use of crop-spray also creates an aerosol that disperses in the atmosphere and then, may settle in waters some distance from the area of application. In order to prevent the addition of these persistent compounds into the environment, DDT and many other organochlorines have been banned in many developed countries. As an alternative, less-persistent and moreă selective insecticides are produced for the similar applications. (b)

Polychlorinated Biphenyls (PCBs) PCBs are not like DDT as a single compound. PCBs have about 209 congeners (same kind). PCBs are lack flammability therefore these compounds are suitable to use as dielectric fluids in capacitors and power transformers. PCBs are also used as de-inking fluids in the recyling of newspapers and placticisers. Improper disposal of transformers and capacitors can contaminate PCBs in the waters. Other sources of contamination are sewage effluent, waste incinerators, toxic dumps or landfill sites. Unlike DDT, PCBs are volatile and can disperse in the atmosphere. However, they may contaminate the groundwater and surface water. As PCBs enter the waters they can biomagnified in fish tissues. This is because PCBs (like DDT) molecules are nonpolar, when fish absorbed them from water, the molecules are stored on body fat (which is also nonpolar) rather than in the blood (which is a highly polar water solution). This is an example of general solubility rule: dissolve like dissolve. The tendency of nonpolar compounds to mix with other nonpolar substances explains how fish or other aquatic organisms store certain highly toxic substances such as PCBs. Figure 6.4 shows the ways of distributing PCBs.

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Figure 6.4: Ways of distributing PCBs

Recent studies have shown that synthetic organic chemicals such as organochlorine pesticides and PCBs could disrupt endocrine systems of humans and wildlife. Reproductive changes in male alligators from Lake Apopka, Florida, embryonic death, deformities, and abnormal nesting behaviour in fisheating birds have attributed to postulated oestrogenic or anti-androgenic effects of some of these chemicals.

6.1.4

Thermal Pollution

Large amount of water from nearby rivers and lakes is used for cooling system of many industrial processes. The water is pumped through the sytem to cool liquids, gases, and equipment, and then returned to the body of the water at high temperature. For example, a cooling system of a nuclear power plant. The water from the river is used to cool water that circulating through the reactor. Heat released from this process is often discharged directly into surface water, causing a drastic increase in water temperature. The harmful effect of thermal pollution is lowering the dissolved oxygen content of water. Rapid changes in water temperature can disrupt aquatic ecosystems in a variety of ways. For example, fish body temperature fluctuates with the surrounding water. When water temperature increases, the metabolic rate of fish and other aquatic organisms also increases. Thus, their need for O2 increases, but the concentration of dissolved O2 is lower at the higher temperature. The depletion of dissolved O2 can harm these aquatic organisms, causing suffocation in fish adapted to cold water conditions.

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Thermal pollution can also interfere with the natural reproductive cycles of fish. Premature hatching of eggs due to artificially raised temperature lead to mass mortality of young fry through starvation. Other adverse effects are the susceptibility of aquatic organisms to parasites and disease, and an increase in solubility of toxic chemicals at higher temperature, leading to an additional hazard.

SELF-CHECK 6.2 Why does the solubility of O2 in water decreases with a rise in temperature?

Furthermore, the warmer water is less dense, so it floats on the cooler water below and prevent O2 from reaching the cooler water. When water flows downstream (far from the plant), the water temperature returns to ambient level. And, the O2 solubility increases and the temperature layering disappears. (see Figure 6.5).

Figure 6.5: Thermal pollution

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Thermal pollution can be controlled by constructing ponds for collecting and cooling water before its release into nearby lakes and streams. Cooling tower is another way to dissipate heat as the water is cooled before it exits the plant. Table 6.3 shows the temperature and gas solubility in water. Table 6.3: Temperature and Gas Solubility in Water TEMPERATURE AND GAS SOLUBILITY IN WATER •

Gas particles are already separated, so ΔHsolute ≈ 0. Because the hydration step is exothermic (ΔHhydr < 0), the sum of these two terms must be negative. Thus, for all gases in water, ΔHsoln < 0: solute(g) + water(l)

saturated solution (aq) + heat

•

This equation means that gas solubility in water decreases with the rising temperature.

•

Gases have weak intermolecular forces, so there are relatively weak intermolecular force between a gas and water.

•

When the temperature rises, the average kinetic energy of the gas particles in solution increases.

•

An increase in the average kinetic energy allows the gas particles to easily overcome these weak forces and re-enter the gas phase.

6.1.5

Radionuclides

Atom is the smallest unit of an element that can exist as a stable entity. It consists of a nucleus at its centre. This nucleus contains protons (positively charged) and neutrons (neutral) which is surrounded by a ÂcloudÊ of electrons (negatively charged). Isotopes of the same element differ from one another in the number of neutrons and hence the mass. But, the number of protons are the same. All isotopes of the same element have identical chemical properties. For example, all uranium atoms contain 92 protons but some uranium have 146 neutrons and others 143 neutrons. The isotopes of uranium containing 146 neutrons is known as uranium-238 because it consists of 92 protons and 146 neutrons. Some isotopes are radionuclides which are radioactive forms of an element. Excess neutrons in some isotopes make them unstable and often emit radiation to reach a more stable form by spontaneous decay. These radionuclides are pollutants that may contaminate water from antropogenic sources.

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There are three types of radiation emitted from the radionuclides; alpha particles, beta particles and gamma rays. They vary in mass and their ability to penetrate. The X-ray is an artificially produced form of radiation that resembles the gamma rays. The radioactivity of a radionuclide depends on the length of its life-times. Table 6.4 shows examples of hazardous radioactive species. Table 6.4: Some Hazardous Radioactive Species

About 80% of radiation is estimated to occur naturally. For example, radium is found in soils and rocks that releases α decay to produce a radioactive gas called radon. The remaining 20% of radiation comes from human activities, some from nuclear energy industry and nuclear weapons testing. Other sources include Xrays used in the diagnosis of bone fractures and in the treatment of cancer. Figure 6.6 shows the natural and man-made sources of radionuclides.

Figure 6.6: Natural and man-made sources of radionuclides

Several major accidents at nuclear power plants have contributed to the contamination of radionuclides in the water. Such reactors normally are sited by a large river or by the sea because they require large amounts of water to act as a coolant medium. The accident may be caused by a malfunctioning valve in the cooling system. Furthermore, disposal of radioactive wastes in deep mines has a risk of leakage from such sites and they would contaminate surface and ground waters.

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The harmful effects of radiation on human health depend on many factors: 1.

amount of radiation

2.

length of exposure

3.

type of radiation

4.

half-life of the radionuclide

5.

age of the individual

6.

part of the body exposed to the radiation.

Radionuclides often accumulate within biological tissues. When the β , γ rays with very high energy are emitted from the unstable radionuclide decay, the radiation damage the cells, leading to a variety of symptoms called radiation sickness. For example, if the nuclei of reproductive cells are damaged, then the result may be genetic mutation.

6.2

WATER AND WASTE WATER TREATMENT

Clean water is necessary for our life. Most natural water sources for human use come from lakes, rivers or reservoirs. The natural water normally contains dissolved, dispersed, and suspended particles which requires energy to remove these types of particles, to make it clean enough for human to use. Many mineral ions such as Fe3+ and NO3- may be present in high concentrations in water. Some of toxic dissolved organic compounds also may be present. Debris and larger particles exist in suspension form. Municipalities treat their water supplies for domestic and commercial uses to ensure save from disease and to eliminate odors and turbidity. Wastewater or sewage was treated to reduce water pollution and euthrophication.

6.2.1

Water Treatment Plant

In the typical municipal water treatment, when the natural water is pumped into a water treatment plant, the largest particles (debris) are physically removed or filtered at the intake site by screens, known as the first step. Then, in the second step, finer particles, including microorganisms are trapped in an Al(OH)3 gel in large settling tanks. The coloidal gel Al(OH)3 is formed when lime (CaO) reacts with cake alum [Al2(SO4)3] via the following reaction. 3CaO(p) + 3H2O(l) + Al2(SO4)3(p)

→

Al(OH)3(colloidal gel) + 3CaSO4(aq)

(6.4)

124 X

TOPIC 6

WATER POLLUTION AND WATER TREATMENT

In the third step, the finer particles are trapped within or adsorbed onto the enormous surface area of the gel by coagulation process. These suspended and colloidal particles then settle out and are filtered through a sand bed. The next step, the filtrate is aerated in a large sprayers (saturated with oxygen) in order to oxidise dissolved organic compounds. Figure 6.7 shows a typical municipal water treatment.

Figure 6.7: A typical municipal water treatment

Then, the water is disinfected by treatment with chlorine gas, which gives the water an unpleasant odor. By adding chlorine into the water, it can react with hydrocarbon to form toxic chlorinated hydrocarbons. However, these compounds can be removed by adsorption onto activated carbon particles. Instead of chlorine gas, other disinfectant can be used (ozone or chlorine dioxide) to kill microorganisms and provide safe drinking water. Debris and grits, colloidal clay, microorganisms, and much of the oxidizable organic matter are disposed through this treatment. Nevertheless, dissolves ions remain in the water. These ions can be removed using ion exchange and reverse osmosis methods.

6.2.2

Sewage Treatment

Sewage treatment plants receive waste from many sources within cities. These include homes, hospitals, schools and industries. Waste water contains human wastes, food residues, paper, soap, detergent, dirt, cloth, microorganisms and a

TOPIC 6

WATER POLLUTION AND WATER TREATMENT

W 125

variety of house chemicals. Sewage treatment can be divided into three stages: Primary treatment, secondary treatment, and tertiary treatment. (a)

Primary Treatment Primary treatment is a mechanical process. Large objects such as stones, and sticks are physically removed by passing the sewage through a series of grates and screens. Sand, dirt, and other solids are settle out in grit chamber. And, the suspended solid organic matter, or sludge settle out in a settling tank.

(b)

Secondary Treatment Secondary treatment is a biological process. Sludge from primary treatment enters a large aeration tank, where anaerobic bacteria are used to remove up to 90% of biodegradable, oxygen-demanding wastes in the aeration tank, converting them to CO2. At the end of this process, the BOD is lowered by as much as 90%. Then, the liquid remaining goes into the secondary settling tank to remove residual organic matter. Most of the suspended solid and microorganisms settle out as sludge in the settling tank (or sedimentation tank). The sludge produced from primary or secondary treatment plant is broken down in a sludge digester, and then incinerated, dumped into a landfill or ocean or land as ferlitizer. After that, the water is chlorinated to kill potentially pathogenic bacteria and protozoans before it is released into the streams, lakes or bays. The scheme of the primary and secondary treatment is shown in Figure 6.8. Although secondary treatment is effectively in reducing BOD, it does little to reduce the concentrations of inorganic ions, particularly NH4+, NO3- and PO43-. These soluble ions can eutrophy the receiving water as they are released with the waste water. Their removal requires tertiary treatment, in which some additional chemical steps are added in the process.

126 X

TOPIC 6

WATER POLLUTION AND WATER TREATMENT

Figure 6.8: Primary and secondary sewage treatment

Figure 6.9 shows the advanced sewage treatment.

Figure 6.9: Advanced sewage treatment

TOPIC 6

WATER POLLUTION AND WATER TREATMENT

W 127

Often only one (or two of these proceses is used to remove specific pollutants in a particular area. This expensive method is not widely used. (c)

Tertiary Treatment Tertiary treatment is an advance stage which removes specific pollutants left in the water after primary and secondary treatment. Many methods can be used to remove the chemicals that remain after the secondary treatment. The tertiary treatment is a series of chemical and physical process which is so costly, and therefore is rarely used unless the water is being released into water bodies requires a high level of purity.

(d)

Pathogens and Disinfection Most natural water sources for human use come from lakes, rivers or reservoirs. If the water bodies contaminate with human and animal wastes, it can cause the spread of pathogenic microorganisms through the water supply. It is the most serious pollution hazard to human health. Disinfectant has been used to keep the water supply free from microbial contamination. The disinfectants currently in use are ozone, chlorine dioxide, and chlorine. Chlorine is the most common disinfectant use in the water and sewage treatment. When chlorine is added to water, it disproportionates via the following reaction: Cl2 + H2O

→

HOCl + H+ + Cl-

(6.5)

Chlorine is widely use because it is an effective and relatively inexpensive disinfectant. However, its use has become controversial because it can introduce organochlorine in drinking water. HOCl produced from the reaction (6.5) is a chlorinating agent which can react with hydrocarbon compounds in water to form a variety of toxic chlorinated compounds. Humic acids are complex molecules that contain benzene rings with a variety of substituents, including hydroxide. Some humid acids dissolve in surface or groundwaters and enter the water supply. When humic acids react with HOCl, chloroform (CHCl3) is formed, which is a suspected liver carcinogen in humans. Therefore, most chlorinated water supplies contain trace levels of chloroform. Nevertheless, activated charcoal can be used to removed the chloroform and most of other organic molecules from the water supply. Other disinfectants are ozone (O3) and chlorine dioxide (ClO2). These alternative chemicals are widely used, especially in Europe. They are more expensive because they are too reactive to be stored or shipped, and must be generated on site. Other disadvantage of these disinfectants is that they

128 X

TOPIC 6

WATER POLLUTION AND WATER TREATMENT

are fast-acting and rapidly decompose. In contrast, HOCl is less reactive. It acts more slowly and persists for some time in the water supply.

Water pollution can be defined as any chemical or physical change in water that adversely affects living organisms. By discharging oxygen demanding wastes into the water bodies, often from domestic wastes can substantially deplete the amount of dissolved oxygen present in water. Overloaded plant nutrients present in water can stimulate the growth of surface algae through eutrophication. This fenomenon also can reduce the oxygen content in water which disrupts the aquatic life. Other antropogenic water pollutants are inorganic toxic metals, organochlorines, heat and radionuclides. Instead of damage to aquatic life, water pollution also can affect human health through the process of biomagnification. This is because some water pollutants, such as PCBs can be transfer into human tissues through food chains. Clean water is necessary for our life. Municipalities treat their water supplies for domestic and commercial uses to ensure freedom from disease and to eliminate odors and turbidity. Water treatment is important to make sure the quality of our drinking water compiles the standard requirement, to ensure it is safe for drinking. While, sewage or wastewater was treated in order to reduce water pollution and euthrophication.

Please answer all the questions below within 15 minutes ( 1 mark each). 1.

Give a definition of water pollution.

2.

What is a cross-media contamination?

3.

Identify two pollutants responsible for euthrophication.

4.

Differentiate the function of primary and secondary sewage treatment.

TOPIC 6

5.

WATER POLLUTION AND WATER TREATMENT

W 129

Following is a statement containing a number of blanks and a list of words. Fill in the blanks of the statement with suitable words provided. Among the major water pollutants are the (i)__________ which are organic wastes discharged into water bodies, and residues of fertilizers such as (ii)______________, and (iii)_____________ . Both types of water pollutants can substantially reduce the (iv)_____________ content in water. biochemical oxygen demand thermal pollution dissolved oxygen

nitrates oxygen-demanding wastes phosphate

Please answer all the questions below within 30 minutes. 1.

Name and describe FOUR types of water pollution. Explain how each damages aquatic life. (8 marks)

2.

Describe TWO anthropogenic euthrophication process.

sources

which

can

accelerate

the

(4 marks) 3.

Give THREE harmful effects of adding oxygen-demanding waste into the river. (3 marks)

4.

Name TWO chemicals which have been used as disinfectant in the water treatment. Explain the disadvantage of each chemical. (5 marks)

Answers TOPIC 1:

ECOSYSTEM

Test 1 1. (c)

2. (a)

3. (d)

9. (b)

10. (a)

11. (b)

4. (c)

5. (a)

6. (a)

7. (c)

8. (c)

Test 2 1.

2.

Lentic System

Lotic system

Closed system High nutrients avaiable The variations in oxygen , temperature and light strongly influence the distribution and adaptations of life Example: lake, pond

Open system High nutrient loss Flow rates determine characteristic of system Example: river

A mangrove is a forest at the edge of the sea or the estuaries and distributed all over the tropical world. The details are as follows:

3.

Ć

An intermediate of salinity difference between ocean and freshwater

Ć

vegetation available ă

Mangrove trees have specific characteristics such as tough root, systems, special bark and leaf sturctures and othe unique adaptations to enable them to survive in their habitatÊs harsh conditions

ă

pneumatophores, (or respiratory roots) and buttressed trunks

ă

Plants like Avicennia and Sonneratia do well in sandy areas, Rhizophora copes with better soft humus and rich mud while Bruquiera favours stiff clay containing little organic matter.

Oligotrophic systems: Oligotrophic lakes have a low surface to volume ratio, water that is clear and appears blue to blue-green in the sunlight. Nutrient content of the water is low, although nitrogen may be abundant, phosphorus is highly limited.

ANSWERS

W 131

Eutrophic systems: A typical eutrophic lake has a high surface to volume ratio; i.e.g the surface area is large relative to depth, It has an abundance of nutrients, especially nitrogen and phosporous, that stimulate a heavy growth of algae and other aquatic plants. 4.

The name and description of all five layers are as follows: Ć

Emergent are the tallest trees and are usually over 50 metres tall. The kapok tree is an example of an emergent.

Ć

Canopy- The sea of leaves blocking out the sun from the lower layers. The canopy contains over 50% of the rainforest wildlife. This includes birds, snakes and monkeys. Liannas (vines) climb to the canopy to reach this sun light.

Ć

The under canopy mainly contains bare tree trunks and liana.

Ć

The shrub layer has the densest plant growth. It contains shrubs and ferns and other plants needing less light. Saplings of emergents and canopy trees can also be found here.

Ć

The forest floor is usually dark and damp. It contains a layer of rotting leaves and dead animals called litter. This decomposes rapidly (within 6 weeks) to form thin humus, rich in nutrients

5. 6.

Palearctic, Nearctic, Neotropical, Ethiopian, Oriental and Australian. (i)

Atmosphere and climate

(ii)

Soil

(iii) Biotic community

TOPIC 2:

LAND USE AND CONVERSATION

Test 1 Part A 1.

(d)

Part B 1.

TRUE

2.

TRUE

3.

FALSE

4.

FALSE

5.

TRUE

2.

(b)

3.

(d)

4.

(a)

5.

(d)

132 X

ANSWERS

Test 2 1

(a)

Wilderness is the lands that have not been greatly disturbed by human activities and that humans visit but do not inhabit.

(b) Removal of trees from a forested area without adequate replanting is called deforestation. (c) Conversion of rangeland, rain-fed cropland, or irrigated cropland to desert-like land is called desertification. (d) Wetlands are lands that are transitional between aquatic and terrestrial ecosystems.

2.

3.

4.

(e)

Urban area is defined as towns or cities plus their adjacent suburban fringes with populations of more than 2,500 people (some countries set the minimum at 10,000-50,000 residents).

(a)

Mineral particle

(b)

Humus

(c)

Living organism

(d)

Water

(e)

air

Two main types of ground transportation: (a)

individual such as cars, motor scooters, bicycles, and walking), and

(b)

mass transit such as buses and rail systems.

Forests play an essential role in global biogeochemical cycles such as those for carbon and nitrogen. For example, photosynthesis by trees removes large quantities of carbon dioxide from the atmosphere and fixes it into carbon compounds. At the same time, oxygen is released into the atmosphere. Forests influence local climate conditions. For example, 50 ă 80% of the moisture in the air above tropical forests comes from trees via transpiration and evaporation. Water from the soil is absorbed by roots, transported through the plant, and then evaporated from their leaves and stems.

ANSWERS

5.

6.

W 133

Urban populations grow in two ways: (a)

by natural increase (more births than deaths) Improved food supplies and better sanitation and health care in urban areas lower the death rate and cause urban populations to grow.

(b)

by immigration (mostly from rural areas). As cities are the main centres for new jobs, higher income, education, innovation, culture, better health care, and trade, people are migrated to urban areas in search of jobs, a better life, and freedom from the constraints of village cultural life. They may also be pushed from rural areas into urban areas by factors such as poverty, lack of land, and declining agricultural work due to the use of modern mechanized machinery in agriculture.

Grasses have a fibrous root system in which many roots form a diffuse network in the soil to anchor the plant and therefore reducing soil erosion. Leaves of grass grow from the base, not the tip. Thus, as long as only its upper part is eaten by animals and its lower part remains, the roots can still continue to develop and grow to its original size (as shown in Figure 1). Therefore, rangeland grass is a renewable resource that can be grazed again and again.

Figure 1: Grasses can be grazed without harm as long as the metabolic reserve is left intact

134 X

7.

ANSWERS

A greenbelt surround a big city is another way to provide open space and control urban growth. Satellite towns can be built outside the belt. Ideally, the outlying towns and the central city are linked by an extensive public transport system (as shown in Figure 2). This arrangement can control urban growth and provide open space for recreation and other nondestructive uses. Many cities in Western Europe and Canadian cities such as Toronto and Vancouver have used this approach.

Figure 2: A greenbelt around a large city

TOPIC 3:

ENVIRONMENTAL DEGRADATION

Test 1 1.

(b)

2.

6.

(a)

7. (a)

(c)

3.

(d)

4.

(c)

5.

(b)

8.

(c)

9.

(d)

10.

(d)

Test 2 1.

(a)

(i)

mobile sources ă pollutants emitted by mobile/moving sources

(ii)

stationary sources ă pollutants emitted by non-mobile sources

ANSWERS

(b)

W 135

(i)

mobile sources ă exhaust from vehicles, evaporation of fuel

(ii)

stationary sources ă petrol stations, oil refineries

(c)

Acidification occurs when rain waters contain the gasses (sulphur dioxide and oxides of nitrogen) from burning of fossil fuels.

(d)

Soil acidification occurs when soil becomes acidic.

The impacts of soil acidification are:

2.

3.

ă

important plant nutrients leached out from soil into water bodies

ă

toxic metals such as aluminium ions are released

ă

availability of phosphates to plants depreciates as it will be bounded with aluminium ions.

(a)

(i)

pollutants emitted from known sources into water bodies.

(ii)

pollutants emitted from various sources or from untraceable sources, e.g. rubbish throwing into water bodies, poor sanitation facilities especially in rural areas.

(b)

Point sources: industries, oil spills, sewage treatment plants. Non-point sources: poor sanitation, poor civic conscious, poor town planning.

(c)

ă

water bodies are polluted from excessive use of fertilizers, and/or pesticides to gain maximum yield.

ă

in most cases, excessive use of fertilizers/pesticides will wash away by during rainwater.

ă

the use of organic wastes (or faeces) may contain pathogens.

ă

improper waste treatment in agriculture farms

(a)

hazardous waste is defined as waste in the form of solid, liquid and gas or any combination, that can cause serious irreversible illness or wastes that have hazard potential to human or environment.

(b)

batteries, paint thinner, pesticide containers

(c)

hazardous wastes usually have properties of corrosive, flammable, reactive, toxic and carcinogenic.

(d)

the stages in wastewater treatment are preliminary, primary, secondary and tertiary stage. Preliminary stage:- large pieces of objects such as stones, rags will be filtered as these materials may cause damage to the equipments.

136 X

ANSWERS

Primary stage:- suspended solids and organic matter will be removed here. Heavy materials or biosolids will sink to the bottom of the tank. Secondary stage:- further removal of suspended solids and organic matter. The trickling filter and activated sludge are commonly used technique. Tertiary stage:- chlorine will be added into the water in order to reduce odour and destroy pathogenic organisms before the water is reused.

TOPIC 4:

GLOBAL ENVIRONMENTAL ISSUES

Test 1 1.

(c)

2.

(c)

3.

(b)

4.

(a)

5.

(d)

6.

(b)

7.

(b)

8.

(a)

9.

(d)

10.

(c)

Test 2 1.

(a)

Troposphere, stratosphere, mesosphere and thermosphere

(b)

the ozone layer filters dangerous ultraviolet radiation from harming organisms on earth.

(c)

it is because CFC are stable, inflammable, low in toxicity and cheap to produce.

(d)

chlorine, bromine and monoxides.

(e)

refer to Figure 7.3 ă

the introduction of CFCs by human activities have cause the ozone layer to deplete.

ă

natural occurring gases such as methane from organic decomposition and nitrous dioxide by denitrification by microorganisms also contribute to the ozone depletion.

ă

the ozone depletion substances (ODS) will then accumulate and be transported to the stratosphere by air movements.

ă

the stable ODS will then turn into reactive halogens by the sunÊs ultraviolet radiation.

ă

the reactive halogens will then degrade the ozone layer.

ANSWERS

2.

W 137

(a)

refer to Table 7.2

(b)

(i)

a change in the climate will bring changes in the distribution of vector-borne diseases. According to scientists, the outbreak of malaria and dengue incidents will be elevated due to the increase of temperature. With the combination of high population and poor sanitation, Asia will be prone to various diseases.

(ii)

the change of climate may alter the duration of monsoon and drought seasons in Asia. The monsoon rain may be prolonged and with poor mitigation and town planning, flooding may be a norm. Besides this, rise of sea level will also occur and this will increase the demand for land (due to inundation) and clean water supply. The demand of clean water will further amplified with the drought season. The drought will affect agriculture and fisheries. This will leads to the domino effect that will lead to further complications.

(iii) the change in climate will bring water stress to agriculture activities. The production of certain food staples will also be affected. Increase in carbon dioxide concentrations will yield better rice production. However, this positive effect will be offset by the increase in temperature. In the marine ecosystem, the food chain will be altered as certain species of fish are prone to high temperatures. The introduction of pollutants into sea water and over-fishing of certain fish species will also amply the situation.

TOPIC 5:

ENVIRONMENT MANAGEMENT POLICY AND REGULATION

Test 1 1.

(a)

2.

(c)

3.

(b)

4.

(d)

5.

(a)

6.

(a)

7.

(d)

8.

(d)

9.

(b)

10.

(c)

Test 2 1.

(a)

EIA enables the identification of the potential pros and cons of projects to local residents and environment.

(b)

(i)

National Development Planning Committee (NDPC) for federal government sponsored projects.

138 X

ANSWERS

(ii)

State Executive Council (EXCO) for state government sponsored projects.

(iii) Local Authorities or Regional Development Authorities (RDA). (iv) Ministry of International Trade and Industry (MIDA) for industrial projects. (c)

Initiator ă person or organization that proposes a project (including improving of present infrastructure). The initiator must include the benefits of the project (to local communities and the environment). Assessor ă person or organization that conducts the project as required by the initiator. General Public ă feedbacks from general public are required before a project can commence. General public have the right to know the pros and cons of having a new infrastructure in their environment (including improvising present infrastructure). Panel of Experts ă experts from various fields are required to contribute their knowledge. They will provide forecast the viability of the proposed project.

(d)

EIA is important because organizations will know whether their project is viable (economically and environmentally) to commence. Organization could also reduce or minimize their loss by rectifying, modifying or stopping their proposed project. EIA also acts as a filter system that filters project that impairs the environment and local community.

2.

(a)

(b)

(c)

ă

create job opportunities ă e.g. collection of old newspapers, aluminium cans

ă

influx of experts and technologies in recycling industry

ă

create a better environment for the future

ă

sustain and improve the current environment for the future

ă

decrease production or use of raw materials

ă

enhances environmental awareness of the public

ă

Establishment of National Recycling Day

ă

Creation of Nature Club by MNS and Malaysian schools

ă

Develop methods for disposing hazardous waste

ă

Minimize generation of hazardous waste

ANSWERS

(d)

3.

(a)

W 139

ă

Treating hazardous wastes close to its source

ă

Reduce the movements of hazardous waste

ă

To reduce the possibility leaking of hazardous waste

ă

To reduce the possibility of illegal transporting of hazardous waste

„Convention‰ - a formal agreement or treaty on common understanding by several countries under an International Organization „Ratify‰ - the approval of a government/parliament to participate in a Convention.

(b)

Greenhouse gas is the gases that cause the greenhouse effect and it absorbs radiation. Two common greenhouse gases are chlorofluorocarbon (CFC) and hydrofluorocarbon (HFC).

(c)

United Nations Framework Convention on Climate Change

(d)

ă

countries share a common goal; preventing further damage on the environment.

ă

moderate (MDC) and less developed countries (LDC) will have scientific and monetary assistance from highly developed countries (HDC).

ă

transfer of green technologies to HDCs to MDCs and LDCs will also be immediate.

ă

Collaborations in this context will be enhanced further.

ă

more sharing and exchanging of information.

ă

educational, training and awareness programmes introduced and intensified in MDCs and LDCs.

ă

countries will share a common environmental regulation.

will

be