Environ Sci Pollut Res DOI 10.1007/s11356-014-3791-x
RESEARCH ARTICLE
Health risk assessment of organochlorine pesticide exposure through dietary intake of vegetables grown in the periurban sites of Delhi, India Sapna Chourasiya & P. S. Khillare & Darpa Saurav Jyethi
Received: 26 June 2014 / Accepted: 29 October 2014 # Springer-Verlag Berlin Heidelberg 2014
Abstract The study investigated the levels of organochlorine pesticides (OCPs) in different types of vegetables grown in periurban area of National Capital Region (NCR), India. Vegetable sampling was carried out in winter and summer season of 2012. A total of 20 different OCPs were determined using gas chromatography (GC) assembled with electron capture detector (ECD). Obtained results showed that average levels of ∑20OCP ranged from 83.8±25.5 ng g−1 in smooth gourd to 222.4±90.0 ng g−1 in cauliflower. The mean concentrations of different OCPs were observed in order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT in all vegetables except in brinjal and smooth gourd. Most of the OCP residues recorded in vegetable samples exceeded the maximum residue levels (MRLs) set by international and national regulatory agencies. Health risk assessment suggests that daily dietary OCP exposure via vegetable consumption was higher for children (mean value 4.25E−05) than adults (mean value 2.19E−05). The hazard quotient (HQ) and lifetime cancer risk (LCR) estimated from dietary exposure of these vegetables were above the acceptable limit and can be considered as a serious concern for Delhi population.
Keywords Organochlorine pesticides . Vegetables . MRL . Daily intake . Hazard quotient . Lifetime cancer risk
Responsible editor: Hongwen Sun S. Chourasiya : P. S. Khillare (*) : D. S. Jyethi Environmental Monitoring and Assessment Laboratory, School of Environmental Sciences, Jawaharlal Nehru University, New Delhi 110067, India e-mail:
[email protected]
Introduction Persistent organic pollutants (POPs) are a group of organic compounds mainly characterized by toxicity, long half-lives, long-range transport, and bio-accumulative properties (Jiang et al. 2009). Organochlorine pesticides (OCPs), a key group of POPs, have aroused major concern among environmental scientist and the public across the world. The United Nation Environment Program (UNEP) through the Stockholm convention on POPs has listed 12 OCPs, namely, aldrin, chlordane, dichlorodiphenyltrichloroethane (DDT), dieldrin, endrin, heptachlor, mirex, toxaphene, α-HCH, β-HCH, lindane, and endosulfan under the POP category. It proposes actions targeting their elimination or reduction in fresh release into the environment. However, widespread use of OCPs during the past six decades in agricultural practices has resulted in the accumulation of these toxic residues in various environmental components such as sediment, soil, dust, animal feed, and vegetables (Nishina et al. 2010; Sharma et al. 2013; Wang et al. 2013). Exposure to OCPs in environment causes various carcinogenic and non-carcinogenic disorders (Shi et al. 2011). In general, dietary intake constitutes principal route of human exposure to OCPs, accounting for >90 % as compared to dermal and inhalation exposure pathways (Mansour et al. 2009). OCPs were detected in a variety of dietary food which includes vegetables and fruits, cereals, oils, meats, eggs, and fishes (Fromberg et al. 2011; Zhou et al. 2012). Vegetables are basic food in the human diet across the world both in terms of quantities consumed and nutritional value. India is one of the countries where majority of the population are vegetarian, and they use vegetables as an important ingredient for the maintenance of health and prevention of diseases (Khillare et al. 2012). Earlier studies in several countries have reported higher incidences of OCP residues in vegetables above their maximum residue levels (MRLs) (Manirakiza et al. 2003;
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Swarnam and Velmurugan 2013). Although the use of most OCPs was banned or restricted in many countries, India is still engaged in the large-scale manufacture and use of some of these toxic OCPs because of their cost-effectiveness, easy availability, and broad spectrum activity (Abhilash and Singh 2009). In order to assure food safety, it is important to understand the OCP residue status in vegetables because most of the time, these are consumed either raw or without much processing (Kumari et al. 2003). In the present study, OCP residues were studied in six different vegetables (radish, radish leaf, cauliflower, brinjal, okra, and smooth gourd) belonging to root, leafy, and fruit type. Rationale behind selection of these vegetables was to evaluate the pattern of OCP contamination in different types of vegetables. In addition to this, these vegetables are commonly grown and consumed in periurban area of National Capital Region (NCR), India. In Indian scenario, there are several studies involving the determination of OCP concentrations in vegetables (Mandal and Singh 2010; Betsy et al. 2013). However, to the best of our knowledge, there is no comprehensive study about vegetable contamination by OCPs, their distribution pattern, sources, and potential health risk via ingestion of different seasonal vegetables in NCR, India. Therefore, the principle objectives of the present work were set (1) to monitor the residual concentration of selected OCPs, their sources, and distribution pattern in various vegetables during winter and summer seasons; (2) to compare the residual concentration with MRLs recommended by different international and national regulatory agencies; and (3) to estimate the potential health risks (cancerous and non-cancerous) associated with each of the selected pesticides via daily intake of contaminated vegetables.
Materials and method
significant changes in the land use pattern of Delhi. Approximately 42 % of the total area in NCR of India accounts for agricultural activity of which 35 % comes under vegetable cultivation. Yamuna river floodplain/ river bed is utilized for cultivation of seasonal vegetables and fruits due to the enriched nutrient status and moisture content of the soil (Babu et al. 2000). Periurban land of Delhi region is also intensively cultivated with vegetable crops because of greater market demand and higher returns to the farmers. The vegetables collected annually from Delhi farms is around 2.2 million tons (NAAS 2004). Such intensive cultivation suffers with the prevailing humid tropical climate and pest infestation and thus heavily relies on the use of pesticides for the control of weeds, pests, and diseases.
Vegetable sampling and processing To investigate the contents of OCPs, vegetable samples were collected during winter and summer seasons in 2012 from seven areas (S1 to S7), having intensive vegetable cultivation in the NCR of India as shown in Fig. 1. Fresh vegetable samples such as radish (root vegetable), radish leaf (leaf vegetable), and cauliflower (fruit vegetable) in winter, and brinjal, okra, and smooth gourd (fruit vegetables) in summer season were collected directly from the agricultural fields. Afterward, raw vegetable samples were put in sterile polyethylene bags, transported to the laboratory, and were kept in refrigerator at 4 °C until analysis. Samples were washed thoroughly with tap water and chopped into small pieces, and only edible portion was selected for further processing. These samples were then extracted and analyzed (within 24 h from the time of their collection from fields) for the presence of OCPs according to method described in the “Analytical procedure” section.
Study area The study was carried out in NCR of India which mainly includes Delhi and adjoining towns. It lies between 27° 03′ to 29° 29′ N latitude and 76° 07′ to 78° 29′ E longitude. The region has humid to semi-arid climatic conditions with three distinct seasons, i.e., summer (March to June), monsoon (July to October), and winter (November to February). The average annual temperature is about 22 °C while annual average precipitation is 500–700 mm. The approximate area of NCR in India is 33,578 km2, of which the major agricultural part is stretched over floodplain of river Yamuna. The Yamuna river floodplains are very fertile as they are enriched with silt and alluvium deposits. Unprecedented population growth, industrial development, and rapid urbanization in the last 25 years has resulted
Fig. 1 Map showing vegetable sampling sites in NCR, India
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Chemicals and reagents Pesticide standard mixture EPA 8081 (46845-U) containing 20 OCP compounds (α-HCH, β-HCH, γ-HCH, δ-HCH, heptachlor, heptachlor epoxide, γ-chlordane, α-chlordane, α-endosulfan, β-endosulfan, endosulfan sulfate, p,p′-DDT, p,p′DDD, p,p′-DDE, methoxychlor, aldrin, dieldrin, endrin, endrin aldehyde, endrin ketone) and two surrogate compounds (2,4,5,6-tetrachloro-M-xylene, decachlorobiphenyl) were procured from Sigma-Aldrich (USA). The certified purities of compounds in reference standard ranged from 97.5 to 99.9 %. Solvents such as acetonitrile, n-hexane, ethyl acetate, and dichloromethane (HPLC grade) were purchased from Merck, India. Florisil (a product of US Silica, 60–100 mesh) was purchased from Fisher Scientific, India. Analytical procedure Extraction and cleanup Fifty-gram amount of the chopped vegetable samples were homogenized with acetonitrile (repeated thrice with 50 ml) in a blender. Further, the resultant mixture was subjected to liquid-liquid partitioning by separatory funnel with 400-ml mixed solvents of n-hexane and dichloromethane (3:2 v/v), followed by shaking for 1 h. After shaking, the separatory funnel was left in the same position for 30 min to have distinct layer of solvents. Hexane layer was then collected into round bottom flask and concentrated to 2 ml by rotary evaporator (Büchi rotavapour) while leftover layer being discarded. After extraction, other impurities were removed by cleanup method using florisil column chromatography (Nakamura et al. 1994). Three grams of Florisil suspended in n-hexane was placed in chromatographic column plugged with cotton wool. Before use, the Florisil was activated at 180 °C for 24 h. Two-milliliter concentrated sample was transferred completely to a Florisil column and eluted with 100 ml mixture of ethyl acetate and n-hexane (3:7 v/v). The fraction containing OCP compounds was further concentrated to 2 ml by rotary evaporator, and solvent was exchanged with hexane for further chromatographic analysis.
temperature 190 °C, held for 2 min, increased to 230 °C at a rate of 1.5 °C min−1, followed by 20 °C min−1 until the final temperature 280 °C at which it was held for 5 min. Helium gas with high purity was used as a carrier gas with the flow rate of 1.2 ml min−1 whereas N2 was set at 30 ml min−1 as a makeup gas. Total run time of the analysis was calculated to be 37 min. Quality assurance/quality control (QA/QC) Analytical procedure used in current study was done with strict quality assurance and control measures. All the glasswares were washed with sulfuric acid/potassium dichromate mixture, afterward rinsed with distilled water and then dried at 120 °C in oven. To find out the cross-contamination and interference, a solvent and procedural blank were also analyzed with each set of samples. None of the targeted OCP compounds were detected in solvent and procedural blanks. An external standard method was used to quantify the OCP residues in the sample extracts. Five ranges of external standard solutions were prepared for calibration curve with good linearity (R2 >0.99). The compounds of interest in samples were identified by their retention time matching with those of reference standards under specified chromatographic condition. The peaks of p,p′-DDE and dieldrin were extremely close and difficult to be distinguished; therefore, these two compounds were combined as one. Estimates of dietary exposure and health risks for OCPs Considering the toxicological effects of OCP compounds, it is important to investigate the potential exposure of humans through dietary intakes and related health risks in terms of non-cancer risk (hazard quotient (HQ)) and lifetime cancer risk (LCR). OCP exposure via vegetable intake and related risks were estimated according to the guidelines recommended by the USEPA (1989a, b, 2011). The daily intake of OCPs via vegetable consumption for adult and children were estimated using Eq. (1). Estimated daily intake mgkg1 day1
¼ ðCV IR E F ED C FÞ=ðBW ATÞ Gas chromatographic determination Sample analysis was performed using gas chromatograph (autosampler, model AOC-20i, GC-2010, Shimadzu) assembled with RTX-5 fused silica capillary column (30 m × 0.25 mm i.d., film thickness 0.25 μm) and electron capture detector (ECD). Two microliters of prepared sample was injected in gas chromatograph (GC). The injector and detector temperature were set at 270 and 300 °C, respectively. The oven temperature was programmed as follows: initial
ð1Þ
where CV is the OCP concentration in vegetables (ng g−1), IR is the vegetable intake rate (196 g day−1, adopted from FAO, food balance sheet, 2009), EF is the exposure frequency (350 days year−1), ED is the exposure duration (70 and 30 years for cancer and non-cancer risk, respectively), CF is the unit conversion factor (10−6), BW is the body weight (70 and 36 kg for adult and children, respectively), and AT is the averaging time (EF × ED, i.e., 25,550 and 10,500 days for cancer and non-cancer risk, respectively).
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In order to evaluate non-cancer effect from dietary OCP exposure, the concept of HQ and hazard index (HI) were used in this analysis. HQ is defined as ratio of exposure levels (expressed as estimated daily intakes) to the reference dose (RfD). RfD is considered to be safe level of exposure over the lifetime. HQ 1 indicates a probability of adverse noncancer effects to be caused. HI was calculated for assessment of overall potential for non-cancer effects posed by more than one OCP compound. HQ ¼ estimated daily intake=R f D
ð2Þ
HI ¼ ∑HQ
ð3Þ
LCR is evaluated by multiplying estimated daily intake with oral slope factor (OSF in (mg kg−1 day−1)−1) using Eq. (4). LCR is presented as the increased probability of developing cancer over the lifetime as a result of exposure to the carcinogen. OSF is defined as the upper bound cancer estimate of carcinogenic potency. LCR ¼ estimated intake OS F
ð4Þ
Table 1 Reference dose and carcinogenic slope factor for various OCPs OCPs α-HCH β-HCH γ-HCH δ-HCH Heptachlor Aldrin Heptachlor epoxide γ-Chlordane α-Endosulfan α-Chlordane p,p′-DDE Endrin β-Endosulfan p,p′-DDD Endrin aldehyde Endosulfan sulfate p,p′-DDT Endrin ketone Methoxychlor
Reference dose (RfD) (mg kg−1 day−1) – – 3×10−4 – 5×10−4 3×10−5 1.3×10−5 5×10−4 6×10−3 5×10−4 – 3×10−4 6×10−3 – – 6×10−3 5×10−4 – 5×10−3
Oral slope factor (OSF) (mg kg−1 day−1)-1 6.3×100 1.8×100 – – 4.5×100 1.7×101 9.1×100 3.5×10−1 – 3.5×10−1 3.4×10−1 – – 2.4×10−1 – – 3.4×10−1 – –
Source: USEPA, IRIS
The RfD and OSF values for the OCP compounds were taken from Integrated Risk Information System (USEPA 2013) (Table 1). Statistical analysis Statistical analyses were performed using SPSS 16 software with statistical significance for the entire test at p=0.05 and extreme significance at p=0.01. To compare the significant difference of various OCP compounds, paired sample t test has been used. Kruskal-Wallis test was performed for comparison of OCP levels in different vegetables.
Results and discussion Radish, cauliflower, brinjal, okra, and smooth gourd are the commonly grown vegetables in winter and summer seasons in periurban region of NCR, India. These vegetables are highly exposed to pesticides which are used for crop protection. Total 52 samples of different vegetables types (leaf, fruit, and root), 26 samples each from winter and summer seasons, were collected from intensive agricultural areas and analyzed for OCP contamination. The estimation of OCPs in the current study is based on fresh weight (wet weight (ww)) of vegetables.
Concentration of OCPs in vegetables Among the 20 investigated OCPs,17 were detected in all the vegetable samples. The remaining three OCPs, viz., methoxychlor, endrin aldehyde, and endrin ketone, were found in ∼71, ∼88, and ∼96 % of the total analyzed samples, respectively. Mean concentrations±standard deviation and ranges of detected OCPs in different vegetables are summarized in Table 2. With respect to individual vegetables, the highest mean concentration of ∑20OCP was detected in cauliflower (222.4±90.0 ng g−1) which was found to be significantly higher (Kruskal-Wallis test, p0.05) collected during summer season. Comparable levels in these three vegetables can be explained by the identical type of vegetable, i.e., fruity vegetable. Overall, the order of OCP concentrations in the studied vegetables was found to be cauliflower > radish leaf > okra > radish > brinjal > smooth gourd. It is important to note that vegetables such as cauliflower and radish leaves, by virtue of having greater exposed area, exhibited higher OCP concentrations. This suggests direct spray and/or atmospheric deposition to be the
1.9±1.7 2.8±2.1 3.5±2.7 2.1±1.3 2.5±1.9 2.2±2.2 2.1±1.2 2.1±1.3 1.2±0.8 127.3 (±43.2)
p,p′-DDE+dieldrin Endrin β-Endosulfan p,p′-DDD Endrin aldehyde Endosulfan sulfate p,p′-DDT Endrin ketone Methoxychlor ∑20OCPs
38.2±26.2 44.6±26.3 24.7±17.0 22.0±24.9 19.4±18.9 24.7±24.6 7.4±8.6 4.7±4.2 5.2±6.4 3.8±2.5
0.3–5.2 2.6±2.8 0.6–6.1 2.5±1.8 0.4–7.8 3.2±3.3 0.6–4.6 1.5±0.9 0.4–6.4 2.5±2.4 0.3–6.3 1.6±1.5 0.3–4.2 3.5±2.7 0.4–3.8 4.3±4.1 ND–2.1 1.9±1.9 89.6–219.9 217.9 (±98.3)
7.8–43.1 7.8–52.3 6.1–21.1 4.3–29.0 0.8–22.7 1.8–32.5 0.4–9.8 0.4–8.9 0.5–9.5 0.8–9.4 0.9–10.2 0.9–6.5 0.6–10.0 0.7–3.2 0.5–8.5 0.3–4.4 0.8–9.0 0.3–14.2 ND–6.1 104.9–416.0
12.4–88.9 17.5–98.9 6.7–61.2 5.3–87.8 0.9–52.7 2.0–76.8 0.7–30.1 0.9–12.4 1.7–21.9 1.5–7.9 3.6±2.0 5.0±4.3 4.4±3.7 3.3±4.1 2.8±1.3 1.8±1.5 3.3±3.3 2.8±1.8 2.2±2.2 222.4 (±90.0)
31.2±17.3 41.4±25.4 26.1±14.3 16.1±12.1 30.2±28.2 25.5±17.5 9.7±11.0 6.7±4.1 4.1±2.7 3.1±3.0
Mean (±SD)
0.9–5.7 1.0–12.3 1.0–11.0 0.6–11.6 1.4–5.2 0.3–4.0 0.3–9.2 1.0–5.0 ND–5.4 95.6–322.7
10.4–51.9 11.1–72.4 6.8–41.4 4.8–38.2 3.7–72.5 7.5–49.3 1.1–26.7 1.9–13.2 2.1–9.2 0.9–8.9
Range
1.5 (±1.3) 3.5 (±4.8) 8.4 (±4.3) 1.3 (±1.1) 2.4 (±1.9) 2.2 (±1.2) 1.7 (±1.8) 2.4 (±3.0) 3.9 (±5.8) 97.4 (±26.8)
14.8 (±6.3) 14.9 (±8.9) 7.2 (±7.3) 6.6 (±5.8) 9.2 (±3.9) 3.9 (±2.7) 2.1 (±2.3) 4.4 (±3.8) 3.8 (±1.9) 3.7 (±3.3) 0.3–4.1 0.8–15.1 3.1–14.1 0.5–3.8 0.3–4.9 0.5–4.1 0.5–6.0 0.4–8.7 0.6–16.6 66.1–135.1
7.9–24.7 6.8–32.7 0.9–22.0 1.1–19.9 1.0–12.8 0.7–9.3 0.4–6.3 0.5–12.7 1.8–7.6 0.5–9.6
Mean (±SD) Range
4.4 (±3.6) 4.5 (±4.3) 6.4 (±3.5) 4.0 (±4.2) 2.5 (±2.1) 2.1 (±1.8) 1.9 (±2.3) 1.4 (±1.4) 2.8 (±2.3) 135.4 (±48.9)
21.2 (±14.4) 23.1 (±11.6) 13.2 (±10.3) 9.5 (±9.7) 10.2 (±6.1) 7.7 (±8.9) 2.3 (±1.7) 8.3 (±7.8) 4.7 (±3.3) 5.4 (±4.0)
Mean (±SD)
Okra (n=9)
HCH hexachlorocyclohexane, DDE dichlorodiphenyl dichloroethylene, DDD dichlorodiphenyl dichloroethane, DDT dichlorodiphenyl trichloroethane
16.5±11.1 24.0±12.7 11.1±5.0 14.5±8.5 11.2±8.2 14.9±11.2 3.8±3.5 3.8±3.4 4.2±3.3 3.5±2.8
Range
Mean (±SD)
Mean (±SD)
Range
Brinjal (n=8)
Radish leaf (n=10)
Radish (n=10)
Cauliflower (n=6)
Summer
Winter
α-HCH β-HCH γ-HCH δ-HCH Heptachlor Aldrin Heptachlor epoxide γ-Chlordane α-Endosulfan α-Chlordane
OCP Compounds
Table 2 Mean concentrations of OCP residues (ng g−1) in winter and summer vegetables from NCR, India
1.0–11.5 0.4–12.7 1.8–12.0 0.4–13.7 ND–7.0 0.6–6.1 0.7–6.5 ND–4.3 ND–6.7 68.7–210.0
6.0–48.0 8.8–41.4 3.6–37. 1.4–31.4 1.9–16.5 0.5–24.1 0.6–5.7 1.1–24.5 1.8–10.6 1.9–15.0
Range
1.2 (±0.9) 1.9 (±2.3) 6.1 (±3.8) 1.4 (±1.3) 1.5 (±1.1) 1.7 (±1.2) 0.9 (±0.8) 1.4 (±0.8) 4.3 (±7.6) 83.8 (±25.5)
13.4 (±6.7) 13.7 (±7.0) 8.2 (±11.7) 8.4 (±5.1) 9.3 (±7.5) 5.7 (±2.7) 1.6 (±1.7) 2.1 (±1.3) 2.0 (±1.2) 1.8 (±1.2)
0.3–3.3 0.4–7.5 1.0–12.0 0.5–4.3 ND–3.2 0.4–4.0 0.3–2.8 ND–2.5 ND–17.9 46.2–116.0
4.9–23.5 4.8–28.0 1.7–38.8 0.4–15.9 1.2–26.3 2.8–10.4 0.3–5.7 1.0–4.7 0.7–4.3 0.4–4.2
Mean (±SD) Range
Smooth gourd (n=9)
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predominant pathway of contamination. Also, these vegetables are grown in winter season having markedly lower temperature and consequently lower photodegradation of OCP compounds. OCP concentrations in radish, an underground vegetable, have been found to have comparable values with that of fruit vegetables such as okra, brinjal, and smooth gourd. From the vegetables grown in summer, okra and brinjal, which are tender and supple in nature are prone to pest attack and are subjected to frequent sprays in a season. Harvest of fruits of okra and brinjal in short intervals have been also known to be the likely reason for high levels of retention of pesticides in fruit vegetables (Singh 2006). Relatively lower values of OCP concentrations in summer time vegetables can possibly be linked to increased photodegradation of these compounds in summer. Concentrations of various OCPs such as ∑HCH (sum of α-HCH, β-HCH, γ-HCH, and δ-HCH), ∑CHLs (sum of α-chlordane, γ-chlordane, heptachlor, and heptachlor epoxide), drins (sum of aldrin, endrin, endrin aldehyde, and endrin ketone), ∑endosulfan (sum of α-endosulfan, β-endosulfan, and endosulfan sulfate), and ∑DDT (sum of p,p′-DDT and p,p′-DDD) in all vegetables of both seasons are shown in Fig. 2a, b. The mean concentrations of OCP compounds in all varieties of vegetables were in decreasing order of ∑HCH > ∑CHLs > drins > ∑endosulfan > ∑DDT, except in brinjal and smooth gourd. The mean concentration of ∑endosulfan was slightly higher than drins in brinjal and smooth gourd. In the present study, concentration of ∑HCH and ∑DDT in all vegetable samples were observed in the range 11.8–250.1 and 1.5–25.7 ng g−1, respectively (Fig. 2a, b). It is noted that mean concentration of ∑HCH was approximately 6 to 17 times higher than ∑DDT concentrations in all varieties of vegetables. This is probably because of continued excessive and indiscriminate use of HCH due to its low cost and popularity among farmers even after ban. This assessment is similar to that of the study conducted by Nakata et al. (2002) which states that ∑HCH is the major contributor of OCPs in foodstuffs and vegetables from Shanghai, China. With respect to ∑HCH contamination, radish leaves and brinjal exhibited the highest (129.5 ng g−1) and lowest (43.5 ng g−1) mean concentration, respectively. Higher concentration of ∑HCH in radish leaves can be understood on the basis of dual pathway of HCH availability in the plant, one by uptake through root system and the other could be via atmospheric deposition of HCH on the large leaf area of radish plant. This observation is an agreement with other studies reported by Barriada-Pereira et al. (2005) and Calvelo Pereira et al. (2006) who attributed higher foliar accumulation of HCH to air-plant partitioning following volatilization from soil. In addition to the above, the other possible reason for higher concentration of ∑HCH in radish leaves could be accumulation following the direct spray on the leaves.
Next to ∑HCH, ∑CHL levels in vegetables were found significantly higher (paired sample t test, p brinjal > smooth gourd. Ratio of α/γ-HCH indicates both lindane and technical HCH use in the study area. Higher concentration of DDT metabolite (p,p′-DDD) indicated that vegetable samples were mainly contaminated by weathered DDT. Most of the OCPs exceeded their prescribed limit set by different international and national agencies. Within the context of European Commission guidelines, the levels of HCHs, heptachlors, chlordane, aldrin, and methoxychlor were found exceeding their respective MRLs. Analysis of health risk revealed that aldrin (for adult and children) and heptachlor epoxide (for children only)
contributes toward non-cancer risk. Moreover, cancer risk associated with dietary exposure of ∑ 20 OCP through vegetable consumption by adults and children exhibited a value in the range of 10−4 to 10−6 indicating its potential risk. Therefore, the cancer risk attributed to OCP exposure is considerable and should be taken into account for future food safety legislation. Thus, it can be concluded from the present study that attention should be paid to the level of OCP contaminants in these vegetables. Apart from this, some other potential species are also available such as tuber root (potato), bulb (onion, turnip), and leguminous vegetable (peas, soybean) which can be used for similar kind of study. There is an urgent need to prevent further release of OCPs into the environment through strict regulatory measures. Nevertheless, monitoring and risk assessment programs are an increasingly important tool and are essential to ensure minimal residue levels in food commodities. Efforts must therefore be continued to build up a database and stricter regulatory legislation in the country. Acknowledgments Fellowship awarded by Council of Scientific and Industrial Research—University Grant Commission (CSIR-UGC), Government of India, to Sapna Chourasiya is duly acknowledged. GC-ECD facility provided by the Advanced Instrumentation Research Facility (AIRF), Jawaharlal Nehru University (JNU), New Delhi, and technical assistance by Dr. Ajai Kumar (AIRF, JNU) are also duly acknowledged.
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References Abhilash PC, Singh N (2009) Pesticide use and application: an Indian scenario. J Hazard Mater 165:1–12 Adeyeye A, Osibanjo O (1999) Residues of organochlorine pesticides in fruits, vegetables and tubers from Nigerian markets. Sci Total Environ 231:227–233 Akoto O, Andoh H, Darko G, Eshun K, Osei-Fosu P (2013) Health risk assessment of pesticides residue in maize and cowpea from Ejura, Ghana. Chemosphere 92:67–73 Arrebola FJ, Egea-González FJ, Moreno M, Fernández-Gutiérrez A, Hernández-Torres ME, Martínez-Vidal JL (2001) Evaluation of endosulfan residues in vegetables grown in greenhouses. Pest Manag Sci 57:645–652 Babu CR, Kumar P, Prasad L, Agrawal R (2000) Valuation of ecological functions and benefits: a case study of wetland ecosystems along the Yamuna river corridors of Delhi region. EERC working paper series: WB-6 Minist Environ For Barriada-Pereira M, González-Castro MJ, Muniategui-Lorenzo S, LópezMahía P, Prada-Rodríguez D, Fernández-Fernández E (2005) Organochlorine pesticides accumulation and degradation products in vegetation samples of a contaminated area in Galicia (NW Spain). Chemosphere 58:1571–1578 Bempah CK, Donkor A, Yeboah PO, Dubey B, Osei-Fosu P (2011) A preliminary assessment of consumer’s exposure to organochlorine pesticides in fruits and vegetables and the potential health risk in Accra Metropolis, Ghana. Food Chem 128:1058–1065 Bempah CK, Buah-Kwofie A, Enimil E, Blewu B, Agyei-Martey G (2012) Residues of organochlorine pesticides in vegetables marketed in Greater Accra Region of Ghana. Food Control 25: 537–542 Betsy A, Vemula SR, Sinha S, Mendu VVR, Polasa K (2013) Assessment of dietary intakes of nineteen pesticide residues among five socioeconomic sections of Hyderabad—a total diet study approach. Environ Monit Assess 186:217–228 Bhanti, M, Taneja A (2005) Monitoring of organochlorine pesticide residues in summer and winter vegetables from Agra, India – a case study. Environ Monit Assess 110:341–346 Calvelo Pereira R, Camps-Arbestain M, Rodríguez GB, Macías F, Monterroso C (2006) Behaviour of α-, β-, γ- and δhexachlorocyclohexane in the soil-plant system of a contaminated site. Environ Pollut 144:210–217 Doong R-A, Peng C-K, Sun Y-C, Liao P-L (2002) Composition and distribution of organochlorine pesticide residues in surface sediments from the Wu-Shi River Estuary, Taiwan. Mar Pollut Bull 45:246–253 Essumang DK, Asare EA, Dodoo DK (2013) Pesticides residues in okra (non-target crop) grown close to a watermelon farm in Ghana. Environ Monit Assess 185:7617–7625 European Commission (2009) Maximum residue levels of pesticides in or on food and feed of plant and animal origin. Commission amending regulation (EC) No 396/2005 of the European parliament and of the council. Amending council directive 91/414/EEC FAO (2009) Food Balance Sheets - India. Food and Agriculture Organization of the United Nations Statistics Division. http:// faostat.fao.org/site/368/DesktopDefault.aspx?PageID=368#ancor. Accessed Nov 2013 FAO/WHO (2012) Codex Alimentarius Commission. Pesticide residues in food and feed. codex pesticide residues in food online database. http://www.codexalimentarius.net/pestres/data/index.html. Accessed October 2013 Fromberg A, Granby K, Højgård A, Fagt S, Larsen JC (2011) Estimation of dietary intake of PCB and organochlorine pesticides for children and adults. Food Chem 125:1179–1187
Hans RK, Farooq M, Babu GS, Srivastava SP, Joshi PC, Vishwanathan PN (1999) Agricultural produce in the dry bed of the river Ganga in Kanpur, India- a new source of pesticide contamination in human diets. Food Chem Toxicol 37:847–852 Janouskova E, Krbuskova M, Rehurkova I, Klimova M, Prokes L, Ruprich J (2005) Determination of chlordane in foods by gas chromatography. Food Chem 93:161–169 Jiang Y-F, Wang X-T, Jia Y, Wang F, Wu M-H, Sheng G-Y, Fu J-M (2009) Occurrence, distribution and possible sources of organochlorine pesticides in agricultural soil of Shanghai, China. J Hazard Mater 170:989–997 Khillare PS, Jyethi DS, Sarkar S (2012) Health risk assessment of polycyclic aromatic hydrocarbons and heavy metals via dietary intake of vegetables grown in the vicinity of thermal power plants. Food Chem Toxicol 50:1642–1652 Kumari B, Madan VK, Kumar R, Kathpal TS (2002) Monitoring of seasonal vegetables for pesticide residues. Environ Monit Assess 74:263–270 Kumari B, Kumar R, Madan VK, Singh R, Singh J, Kathpal TS (2003) Magnitude of pesticidal contamination in winter vegetables from Hisar, Haryana. Environ Monit Assess 87:311–318 Lal R, Dhanraj PS, Narayan rao VVS (1989) Residues of organochlorine insecticides in Delhi vegetables. Bull Environ Contam Toxicol 42: 45–49 Malik A, Ojha P, Singh KP (2009) Levels and distribution of persistent organochlorine pesticide residues in water and sediments of Gomti River (India)—a tributary of the Ganges River. Environ Monit Assess 148:421–435 Mandal K, Singh B (2010) Magnitude and frequency of pesticide residues in farmgate samples of cauliflower in Punjab, India. Bull Environ Contam Toxicol 85:423–426 Manirakiza P, Akinbamijo O, Covaci A, Pitonzo R, Schepens P (2003) Assessment of organochlorine pesticide residues in West African city farms: Banjul and Dakar case study. Arch Environ Contam Toxicol 44:171–179 Mansour SA, Belal MH, Abou-Arab AAK, Ashour HM, Gad MF (2009) Evaluation of some pollutant levels in conventionally and organically farmed potato tubers and their risks to human health. Food Chem Toxicol 47:615–624 Mukherjee I (2003) Pesticides residues in vegetables in and around Delhi. Environ Monit Assess 86:265–271 NAAS (2004) (National Academy of Agricultural Sciences, India) – Policy Paper 26 – Peri-Urban Vegetable Cultivation in the NCR Delhi. pp 1–6 Nakamura Y, Tonogai Y, Sekiguchi Y, Tsumura Y, Nishida N, Takakura K, Isechi M, Yuasa K, Nakamura M, Kifune N, Yamamoto K, Terasawa S, Oshima T, Miyata M, Kamakura K, Ito Y (1994) Multiresidue analysis of 48 pesticides in agricultural products by capillary gas chromatography. J Agric Food Chem 42:2508–2518 Nakata H, Kawazoe M, Arizono K, Abe S, Kitano T, Shimada H, Li W, Ding X (2002) Organochlorine pesticides and polychlorobiphenyls residues in foodstuffs and human tissues from China: Status of contamination, historical trend and human dietary exposure. Arch Environ Contam Toxicol 43:473–480 Nishina T, Kien CN, Noi NV, Ngoc HM, Kim C-S, Tanaka S, Iwasaki K (2010) Pesticide residues in soils, sediments, and vegetables in the Red River Delta, northern Vietnam. Environ Monit Assess 169:285–297 Osman KA, Al-Humaid AI, Al-Rehiayani SM, Al-Redhaiman KN (2011) Estimated daily intake of pesticide residues exposure by vegetables grown in greenhouses in Al-Qassim region, Saudi Arabia. Food Control 22:947–953 Owago OJ, Qi S, Xinli X, Yuan Z, Sylvie MA (2009) Residues of organochlorine pesticides in vegetables from Deyang and Yanting areas of the Chengdu economic region, Sichuan Province, China. J Am Sci 5:91–100
Environ Sci Pollut Res Pandey P, Khillare PS, Kumar K (2011) Assessment of organochlorine pesticide residues in the surface sediments of River Yamuna in Delhi, India. J Environ Prot 2:511–524 PFA (1954) ACT No. 37 with prevention of food adulteration act & rules 1955 (as on 1.10.2004) Rand GM, Carriger JF, Gardinali PR, Castro J (2010) Endosulfan and its metabolite, endosulfan sulphate, in freshwater ecosystems of South Florida: a probabilistic aquatic ecological risk assessment. Ecotoxicology 19:879–900 Sharma HR, Kaushik A, Kaushik CP (2013) Organochlorine pesticide residues in fodder from rural areas of Haryana, India. Toxicol Environ Chem 95:69–81 Shen L, Xia B, Dai X (2013) Residues of persistent organic pollutants in frequently consumed vegetables and assessment of human health risk based on consumption of vegetables in Huizhou, South China. Chemosphere 93:2254–2263 Shi W, Zhang F, Zhang X, Su G, Wei S, Liu H, Cheng S, Yu H (2011) Identification of the trace organic pollutants in freshwater sources in Eastern China and estimation of their associated human health risks. Ecotoxicology 20:1099–1106 Simonich SL, Hites RA (1995) Organic pollutant accumulation in vegetation. Environ Sci Technol 29:2905–2914 Singh A (2006) Integrated pest management strategies for okra and Brinjal. National Centre for Integrated Pest Management (ICAR) Pusa Campus, New Delhi Singh KP, Malik A, Mohan D, Sinha S (2005) Persistent organochlorine pesticide residues in alluvial groundwater aquifers of Gangetic Plains, India. Bull Environ Contam Toxicol 74:162–169 Singh KP, Malik A, Sinha S (2007) Persistent organochlorine pesticide residues in soil and surface water of northern Indo-Gangetic alluvial plains. Environ Monit Assess 125:147–155 Swarnam TP, Velmurugan A (2013) Pesticide residues in vegetable samples from the Andaman Islands, India. Environ Monit Assess 185:6119–6127 USEPA (1989a) Risk assessment guidance for superfund, volume i: human health evaluation manual, EPA/540/1-89/002. US Environmental Protection Agency, Washington, DC USEPA (1989b) Exposure factor handbook, EPA/600/8-89/043. US Environmental Protection Agency, Washington, DC USEPA (1996) Soil screening guidance: technical background document. EPA/540/R-95/128. Office of solid waste and emergency response.
http://www.epa.gov/superfund/health/conmedia/soil/pdfs/part_2.pdf. Accessed October 2013 USEPA (2001) Supplemental guidance for developing soil screening levels for superfund sites. OSWER 9355.4-24. Office of solid waste and emergency response. http://www.epa.gov/superfund/health/ conmedia/soil/pdfs/ssg_main.pdf. Accessed October 2013 USEPA (2011) Exposure factor handbook, EPA/600/R-090/052 F. US Environmental Protection Agency, Washington, DC USEPA, IRIS (Integrated Risk Information System) compares IRIS values. http://cfpub.epa.gov/ncea/iris/compare.cfm. Accessed Nov 2013 Walker K, Vallero DA, Lewis RG (1999) Factors influencing the distribution of lindane and other Hexachlorocyclohexanes in the environment. Environ Sci Technol 33:4373–4378 Wang H-S, Sthiannopkao S, Du J, Chen Z-J, Kim K-W, Mohamed Yasin MS, Hashim J-H, Wong C-K-C, Wong MH (2011) Daily intake and human risk assessment of organochlorine pesticides (OCPs) based on Cambodian market basket data. J Hazard Mater 192:1441–1449 Wang N, Yi L, Shi L, Kong D, Cai D, Wang D, Shan Z (2012) Pollution level and human health risk assessment of some pesticides and polychlorinated biphenyls in Nantong of Southeast China. J Environ Sci 24:1854–1860 Wang W, Huang M-J, Wu F-Y, Kang Y, Wang H-S, Cheung KC, Wong MH (2013) Risk assessment of bioaccessible organochlorine pesticides exposure via indoor and outdoor dust. Atmos Environ 77:525–533 Willett KL, Ulrich EM, Hites RA (1998) Differential toxicity and environmental fates of hexachlorocyclohexane isomers. Environ Sci Technol 32:2197–2207 Yi Z, Zheng L, Guo P, Bi J (2013a) Distribution of α-, β-, γ-, and δhexachlorocyclohexane in soil-plant-air system in a tea garden. Ecotoxicol Environ Saf 91:156–161 Yi Z, Guo P, Zheng L, Huang X, Bi J (2013b) Distribution of HCHs and DDTs in the soil–plant system in tea gardens in Fujian, a major tea-producing province in China. Agric Ecosyst Environ 171:19–24 Zhou P, Zhao Y, Li J, Wu G, Zhang L, Liu Q, Fan S, Yang X, Li X, Wu Y (2012) Dietary exposure to persistent organochlorine pesticides in 2007 Chinese total diet study. Environ Int 42:152–159
