EXPOSURE TO NEPHROTOXIC POLLUTANTS IN LAS BRISAS COMMUNITIES, EL SALVADOR

EXPOSURE TO NEPHROTOXIC POLLUTANTS IN LAS BRISAS COMMUNITIES, EL SALVADOR Alejandro López1, Alexandre Ribó1, Roberto Mejía1, David Alfaro1, Edgar Quinteros1, Wilfredo Beltetón1, Carlos M. Orantes1, Carlos Hernández1, Dina L. López2 1National

Institute of Health, Ministry of Health of El Salvador, C.A. 2Department of Geological Sciences, Ohio University, United State of America

Introduction

Runoff analysis

Arsenic in water

El Salvador is a developing country with volcanic landscapes located in Central America. El Salvador is overpopulated and has heavily damaged environment mainly due to uncontrolled pollution and agricultural activities. Due this environmental damage, Salvadoran population is exposed to environmental pollutants as heavy metals and pesticides. In addition, in El Salvador there are several stockpiles of obsolete pesticides, most of them, located in populated areas (Map 1). Las Brisas communities are located in a suburban area northeastern of San Miguel city and close to agricultural areas. Until 2009, stockpiles of obsolete pesticides from a pesticide factory (AGROJELL. S.A. de C.V.) were located near Las Brisas communities. This factory was active since 1980 to the nineties and was abandoned with several metal barrels filled with Toxaphene and other contaminants. According WHO, Toxaphene is an obsolete pesticide that has to be banished worldwide. According USEPA Toxaphene intoxication produces kidney, liver and nervous system injuries. A study by salvadoran Environmental and Natural Resources Ministry (MARN) identified Toxaphene water pollution in 9 wells located in the community (MARN 2010). Heavy metal and pesticide exposures are serious threats to human and environmental health. Arsenic (As) is a common water pollutant in El Salvador due to hydrothermal fluids related to the volcanic environment (López et al. 2012). However, anthropic sources related to industrial and urban wastes and to agrochemical impurities also seem to contribute to pollution. Arsenic is a toxic element with carcinogenic and nephrotoxic properties. Paraquat is the pesticide most widely used in El Salvador and it causes the highest number of acute poisoning according Ministry of Health of El Salvador data. Paraquat acute poisoning produce kidney, liver and lung injuries. Paraquat has not been assessed before in Las Brisas. A previous medical study was carried out in these communities (Orantes et al. 2014). It identified a high prevalence of Chronic Kidney Disease that is not explained by traditional causes. This type of disease was described as a chronic interstitial nephritis related to environmental toxicity and occupational risk factors.

Map 2. Surface water with high levels of Arsenic in El Salvador

High Arsenic content in water is a problem widespread in El Salvador. Map 2 shows the Salvadoran basins with highest contents of Arsenic in surface waters. The majority of sampled points with Arsenic contents exceeding the standards proposed by the Salvadoran guidelines for drinking water safety (NSO 13.07.01.08) are located close volcanoes or volcanic lakes (i.e. Olomega lake, Ilopango lake, Coatepeque lake and Laguna Verde). However, urban and industrial wastes from major cities as San Salvador or San Miguel, also can contribute to the Arsenic content. Map 2 was built with data stemmed from MARN, MINSAL and Lopez et al.2012. Map 3. Arsenic in surface water and groundwater Las Brisas Communities

Runoff analysis of the study area shows that former pesticide factory is in the top of small draining area that comprises Las Brisas communities. In general this catchment area has a gentle slope (1-3%), thus there is not high erosion rate. However, runoff caused by heavy rains, i.e. tropical storms or hurricanes (relatively common in El Salvador), can remobilize chemical waste particles present in the plant, transport them downslope and deposit them in community area. Further studies should carry out soil analysis in order to identify Toxaphene and Arsenic in this runoff area.

Identified pollutants Active ingredient

The aims of this study are identifying risk of population exposure to Arsenic and Paraquat in water and evaluating the possible sources of water pollution.

Map 1. Inventory of obsolete pesticide stockpiles in El Salvador

Map 5. Runoff analysis Las Brisas Communities

Highest value

Toxicology (WHO)

CAS

Toxaphene (MARN, 2010)

Obsolete

Paraquat (Present study)

II Moderate Toxicity

4685-14-7

--

7440-38-2

Arsenic (Present study)

8001-35-2

Chemical Family

Health Effects

Endocrine disorders, Organochlorine nephrotoxic, carcinogenic. Nephrotoxic, liver and lung damage, Bipyridyl associated to Parkinson Neprhotoxic, carcinogenic, -neurotoxic

Solubility (H2O)

Median solubility

Soluble

Soil Persistence

Long persistence (1 – 14 years)

Medium persistence (3 years)

None*

Long persistence

*Solubility classification according to inorganic Arsenic. Arsenic can be soluble in combination with other elements under determined temperature ranges.

Discussion and Conclusions

Methods Waters from community wells (groundwater) and surrounding rivers (surface water) during dry season in 2014 were sampled. Samples chemical analysis was carried out by the National Reference Laboratory of Ministry of Health of El Salvador (MINSAL) in order to identify Arsenic and Paraquat content. All samples were georeferenced through GPS device and resulting laboratory data was stored in databases compatible with Geographical Information System (GIS).

As Map 3 shows, in the study area there is presence of Arsenic in rivers and groundwater water. Arsenic content is higher in water from wells surrounding the former pesticide factory reaching a maximum value of 0.01 mg/L (E*), which is equal to standard proposed by Salvadoran guidelines for drinking water safety NSO 13.07.01.08.

Paraquat in water Map 4. Paraquat in surface water and groundwater Las Brisas Communities

Between 2010 and 2014, several field trips were carried out in the communities area and in former factory AGROJELL S.A. de C.V. in order to identify, through visual inspection, possible pollution sources. Runoff analysis around former factory area was carried out though GIS software (ArcGIS® ESRI). Environmental sampling (dry season-2014) Samples

Surface water (rivers): 7 Groundwater (wells): 14

Laboratory analysis Paraquat Arsenic

Former pesticide factory Agrogell S.A de C.V.

Picture 1. Barrels full of Toxaphene.*

Picture 2. Chemical waste dump .*

Picture 3. Chemical waste found in soil.**

Between 2010 and 2014 several inspections in former pesticide factory were carried out. During these inspections, chemical wastes in the facility floor were identified (Picture 3). These wastes were dark solid substances with an intense odor similar to Toxaphene odor. Today the ruins are not guarded and there is not any wall around the ruined plant to prevent the entrance.

Picture source: Dra. Alfonsina Chicas (MINSAL)* and National Institute of Health (MINSAL)**

Former pesticide factory is accessible and still poses major threats because there are chemical and laboratory wastes on the plant’s floor. The source of Paraquat contamination seems related to agricultural activities in agricultural areas. Note that the areas down from the factory in the Rio Grande river do not have high levels of Paraquat suggesting a different source. Chemical wastes in former pesticide plant or the volcanic soils could be the source of Arsenic in the nearby community wells. Majority of settlements of Las Brisas are located down gradient from Agrojell factory. Runoff waters derived from former pesticide factory can contaminate soils, surface and groundwater of these communities. Soil pollution in the communities should increase after heavy rains due to sedimentation of chemical waste particles remobilized from former factory. Further studies should carry out soil analysis in order to identify Toxaphene in this runoff area.

Spectrophotometer UV-VIS Graphite furnace atomic absorption

In 2010, when Environment and Natural Resources Ministry of El Salvador retired chemical waste stockpiles from former factory AGROJELL S.A. de C.V, the facility was in very poor state, almost totally demolished. Chemical stockpiles were constituted by 92 metal barrels full of Toxaphene wastes. These barrels were stored at open air (Picture 1) and some of them had rust holes (Picture 1) and a portion of chemical waste was dumped (Picture 2).

Arsenic and Paraquat contaminants occur in rivers and groundwater of Las Brisas communities. At some sampling points standards proposed by Salvadoran guidelines of drink water quality are exceeded. Thus, groundwater and surface waters of the communities cannot be used for human consumption and are a serious threat to local ecosystems.

Map 4 shows dangerous content of Paraquat in groundwater and surface water of Las Brisas, reaching more than 20 times the standard (E=0.031 mg/L) proposed by Salvadoran guidelines of drinking water quality (NSO 13.07.02:08). The water sample with highest concentration of Paraquat was obtained from a stream southeastern of the community; however, values among 1 and 1.5 mg/L were obtained in domestic wells in Las Brisas communities. Instrumentation detection-quantification limit (DQL) was 0.62 mg/L, a value twenty times higher than the Salvadoran standard (0.031 mg/L), thus values lower than DQL could exceed the standard. According distribution of agricultural areas, farming activities are the most probable source of Paraquat pollution and maybe can contribute to Arsenic pollution (e.g. impurities in fertilizers).

Las Brisas population presents serious exposure to Arsenic, to Paraquat and Toxaphene. These nephrotoxic pollutants could explain the high prevalence of the chronic interstitial nephritis that has been identified in this population. Clinical toxicological studies to local population should be carried out in order to identify the possible links between the nephrotoxic pollution and this type of chronic kidney disease and also with other related diseases.

References  López et al. (2012). Arsenic in volcanic geothermal fluids of Latin America. Science of the Total Environment 429. 57- 75  Orantes CM et al. Epidemiology of Chronic Kidney Disease in Adults of Salvadoran Agricultural Communities. MEDICC Rev. 2014 Apr;16(2):23–30. Available in: http://www.medicc.org/mediccreview/index.php?lang=es&id=351  Ministerio de Medio Ambiente y Recursos Naturales-MARN. Las huellas del toxafeno. 2010 Available in: http://www.marn.gob.sv/index.php?option=com_content&view=article&catid=162:especiales&id=70 0:las-huellas-del-toxafeno Last visit: 12/07/2015  United States Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances. Protect yourself from pesticides: guide for pesticides handlers. Washington DC: United States Environmental Protection Agency; 2006 Jun. 109 p. National Institute of Health, Ministry of Health of El Salvador www.clinicalili.org 2015