Occurrence, distribution and possible sources of organochlorine pesticide residues in tropical coastal environment of India: an overview

Organochlorine pesticides (OCPs) are an important potential component of chemical pollutants used extensively for agriculture and sanitation purposes in India as these are comparatively cheap and effective. These persistent organic compounds such as HCH isomers, DDT and its metabolites are the predominant chemical contaminants found along the Indian coast and thus constitute both alluring and grave areas of scientific research. Our objective in the paper is to provide a comprehensive account of the distribution of organochlorine pesticides in biotic and abiotic compartments of the Indian coastal environment, make some comments on their environmental sources, their movement through the food chain and possible ecotoxicological risk of health in biota including humans. The prevalent HCH, DDT and HCB concentrations differ markedly in eastern and western coast of India reflecting differing agricultural and other usage and their ultimate input into the coastal environment by several rivers and the bioturbation activities of macrozoobenthos (bivalve mollusks, polychaetous annelids, etc.). In several cases, the DDT levels exceeded the effects range-low (ER-L) and could thus cause acute biological impairments, in comparison with the sediment quality guidelines. Contributions of DDT metabolites (DDT, DDD and DDE residues) vary in different Indian coastal regions predominated by pp'-DDT and pp'-DDD. Measured concentrations of HCHs were lower than DDTs that might be due to higher water solubility, vapor pressure and biodegradability of the latter. HCH and DDT residues in fish in India were lower than those in the temperate countries indicating a lower accumulation in tropical fish, which might be related to rapid volatilization of this insecticide in the tropical environment. The concentrations of other chlorinated pesticides (aldrin, dieldrin, eldrin, methoxychlor, endosulfan sulphate) were lower and not generally of great concern.     

Evaluation of the concentration of HCH, DDT, HCB, PCB and PAH in the sediments along the lower stretch of Hugli estuary, West Bengal, northeast India

Detailed analyses of persistent organic pollutants (POPs) such as hexachlorocyclohexane (HCH) isomers (HCHs), dichlorodiphenyltrichloro ethane (DDT) and its metabolites (DDTs), hexachlorobenzene (HCB) and congeners of polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) in surface sediments from the coastal estuarine environment of West Bengal, northeast India allowed the evaluation of the contamination status, distribution and possible pollution sources. HCH, DDT, HCB, PCB and PAH were identified compounds in all the samples, whereas the concentrations of chlorinated pesticides (trans-eptachlorepoxide, dieldrin, endrin, metaoxychlor and mirex) were below the detection limits and were not of great concern. The pesticides did demonstrate markedly different distributions reflecting different agricultural and domestic usage in the region. The range of concentrations of HCH, HCB, DDT and PCBs in the sediments were 0.11-0.40, <0.05-0.98, 0.18-1.93 and 0.18-2.33 ng/g dry wt, respectively. Overall elevated levels of HCB, DDT and PCB were recorded at Babughat, a very closely located site of the metropolitan megacity Calcutta. Fluoranthene (flu) and pyrene (py), the dominant 4-ring PAHs, also showed an abrupt elevated concentrations at Babughat with values of 214 and 144 ng/g dry wt, respectively. Among the isomers and metabolites of HCH, DDT and PCB, alpha-HCH, pp'-DDT and PCB (101), PCB (118), PCB(153) and PCB (138) were found to be dominant. High ratios of metabolites of DDT to SigmaDDTs reveal recent use of DDT in this coastal environment. Fluoranthene, pyrene, 1,2-benzo(a)anthracene and chrysene formed the dominant congeners out of 19 identified PAHs. The sources of contamination are closely related to human activities such as domestic and industrial discharge, automobile exhausts, street runoff, slum sewage, agricultural chemicals and soil erosion due to deforestation as well as atmospheric transport. This study is compared to other coastal and estuarine environments in India and abroad. The baseline data can be used for regular ecological monitoring, considering the industrial and agricultural growth around this important estuarine ecosystem.     

Assessment of organochlorine pesticide residue levels in dairy milk and buffalo milk from Jaipur City, Rajasthan, India

The widespread application of pesticides in agriculture, public health, and industry and in and around the home can result in the accumulation of pesticides in the environment. Therefore, a survey has been conducted during 1993-1996 to investigate the magnitude of contamination of bovine milk with organochlorine pesticide (OCP) residues from Jaipur City, Rajasthan, India. Milk samples, i.e., dairy (toned and whole) and buffalo milk, were collected seasonally, and pesticide residues were assessed using a gas chromatograph (GC) with an electron capture detector (ECD). The results indicate that all the milk samples were contaminated with dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDE and p,p'-dichlorodiphenyldichloroethane [DDD]), isomers of hexachlorocyclohexane (HCH; alpha, beta, and gamma), heptachlor and its epoxide, and aldrin. Seasonal variations of these pesticide residue levels were also observed in all the milk samples. Samples collected during winter season were found to contain higher residue levels as compared to other seasons.     

DDT and HCH residue load in mother's breast milk: a survey of lactating mother's from remote villages in Agra region

Breast milk is the natural and optimal food for the infants. In addition to meeting the nutritional needs, breast milk provides numerous immunological, developmental, psychological, ecological and practical advantages. The levels of the DDT and HCH residues in human milk collected from remote rural part of Agra were analysed. Beta and gamma isomers of HCH accounts for the major residue of total HCH excreted in breast milk. Delta-HCH was not detected in the samples. 95% of the samples were found to be contaminated with DDT and its metabolites. DDD was found in 88% of the samples analyzed. The total concentration of DDT and HCH were found lower than the previous studies carried out in India. The study shows the decreasing levels of these organochlorine pesticides from the environment. Total concentration of total DDT is higher than total HCH.     

Contamination of fish by organochlorine pesticide residues in the Ouémé River catchment in the Republic of Bénin

In the Republic of Bénin, aquatic ecosystems are subject to poisoning risks due to the inappropriate use of pesticides, such as washing of empty bottles in rivers and using pesticides to catch fish. In some areas, cotton fields are located near riverbanks, increasing the probability of pesticide emission to the river. To assess contamination levels in the Ouémé River catchment area, different fish species were collected from different geographical areas along the river. DDT, its metabolites and isomers were the most frequently identified pesticides in fish flesh, alpha-endosulfan, beta-endosulfan, dieldrin, telodrin, lindane and octachlorostyrene were also detected. Concentrations of pesticide residues in fish ranged from 0 to 1364 ng/g lipid. A preliminary risk assessment indicated that the daily intake of chlorinated pesticides by people consuming fish from the Ouémé River still is rather low and does not present an immediate risk.     

Organochlorine and organophosphorous pesticide residues in the Ouémé River catchment in the Republic of Bénin

The Ouémé River is one of the most important rivers in the Republic of Bénin. It is 510 km long and its catchment drains 75% of the country. In this study, organochlorine and organophosphorous pesticide residues were measured in more than 35 sediment samples collected on nine locations along the Ouémé River from upstream to downstream. Except for one location, Tanéka-Koko, all areas were contaminated by more than 20 pesticides. Organochlorine pesticides identified in sediment samples included pp'-DDE, op'-DDD, pp'-DDD, op'-DDT, pp'-DDT, alpha-endosulfan, beta-endosulfan, endosulfan sulphate, alpha-HCH, beta-HCH, lindane, aldrin, dieldrin, endrin, telodrin, isodrin, cis- and trans-heptachlorepoxide, hexachlorbutadiene, hexachlorobenzene and octachlorostyrene. The organophosphorous pesticide chlorpyrifos, used in a new formulation to protect cotton, was also identified. In some areas, the concentrations of organochlorine pesticides in the sediment of the Ouémé River exceeded environmental quality standards and are reason for concern.     

Distribution of PCBs, HCHs and DDTs, and their ecotoxicological implications in Bay of Bengal, India

Analyses of environmentally persistent pollutants like polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH) isomers, and dichlorodiphenyltrichloroethane (DDT) and its metabolites in seawater and sediment samples collected from six locations along the east coast of India were carried out using High-Resolution Gas Chromatograph with High-Resolution Mass Spectrometer (HRGC-HRMS). Sediment and water from Chennai harbour and Cuddalore fishing harbour contained higher concentration of all the compounds. The highest concentration (6570 pg/g dry weight) of total PCB was found in sediment from Chennai harbour followed by sediments sampled in Chennai (opposite to Cooum River mouth) (505 pg/g), Cuddalore fishing harbour (335 pg/g) and Mandapam (251 pg/g). Concentrations in other locations were two orders of magnitude lower than Chennai harbour. A distinct PCB distribution pattern in sediment was observed between harbours and other locations. Greater concentrations of tetra-, penta- and hexachlorobiphenyls were observed in sediments of harbours and opposite to Cooum river mouth, but in other locations lower chlorinated biphenyls (di, tri and tetra-) were more. In seawater, HCH concentration was greater than DDT, but it was quite opposite in sediments. Elevated levels of DDT in sediment were observed only at highly populated urban locations, reflecting the local usage and input of this pesticide. Based on sediment/water quality criteria/guidelines, some coastal locations of the Bay of Bengal could be designated as being polluted by DDTs and gamma-HCH (lindane), but not by PCBs. This investigation reveals the declining trend on the environmental burden of persistent pesticides in Indian marine environment. Data on the organochlorine concentrations found in this survey can be used as reference levels for future POPs monitoring programme.     

Simultaneous biological removal of endosulfan (alpha+beta) and nitrates from drinking waters using wheat straw as substrate

Nitrate and endosulfan (alpha+beta) removal was studied in an upflow biological denitrification reactor packed with wheat straw as carbon source and support particles for microorganisms. While almost complete nitrate elimination and between 65% and 70% endosulfan (alpha+beta) elimination occurred when the temperature was higher than 20 degrees C; below that value, nitrate removal efficiency decreased to about 10%. Nitrate, dissolved organic carbon (DOC), and endosulfan (alpha+beta) removal efficiencies decreased considerably at 1500 microg/l endosulfan concentration in the batch experiments. Although a high removal efficiency was observed for endosulfan (alpha+beta) and nitrate in the biological denitrification continuous reactor, the effluent water could not be used for drinking purpose because of the unacceptable levels of endosulfan (alpha+beta), colour and dissolved organic content. During the continuous study, 23.4% of the initial weight of wheat straw was lost and 24 g was consumed per gram of nitrogen removed. The results of the continuous study showed that 21.3% of the endosulfan removal was achieved by adsorption onto the wheat straw and 68.2% of the endosulfan removal occurred by biological activity and the remaining portion was detected in the effluent water.     

Distribution of pesticides, PAHs and heavy metals in prawn ponds near Kolleru lake wetland, India

This paper discussed the distribution of pesticides, polycyclic aromatic hydrocarbons (PAHs) and heavy metals in water, sediment and prawn from intensive prawn ponds (n=8) near the Kolleru lake wetland, India and assessed the quality of prawn for human consumption and also discussed the possible effects of these pollutants on pond environment and aquatic environment. The chemicals and other products used in prawn ponds near the Kolleru lake wetland were documented. The sediment, prawn and water samples were collected six times from selected prawn ponds during the production period of 3 months. Water samples were analyzed for selected physico-chemical parameters. The levels of pesticides, PAHs and heavy metals were found to decrease in the order sediment followed by prawn and water. The maximum concentrations of pesticides in sediment, prawn and water were alpha-BHC (174.2 microg g(-)(1)), gamma-BHC (234 microg g(-)(1)), malathion (256 microg g(-)(1)), chloripyrifos (198.5 microg g(-)(1)), endosulfan (238 microg g(-)(1)), dieldrin (19.6 microg g(-)(1)) and p,p'-DDT (128.6 microg g(-)(1)). Isodrin was found below detectable limit. The maximum concentrations of PAHs in sediment, prawn and water are anthracene (0.901 microg kg(-)(1)), fluranthene (0.601 microg kg(-)(1)), pyrene (0.786 microg kg(-)(1)), chrysene (0.192 microg kg(-)(1)), benzo(a)pyrene (0.181 microg kg(-)(1)) and benzo(ghi)perylene (227 microg kg(-)(1)). Benzo(e)pyrene, perylene, isomers of dibenzoanthracene and coronene were found below detectable limits. The maximum concentrations of heavy metals in sediment, prawn and water and also in prawn feed are Cu (791 microg g(-)(1)), Pb (270 microg g(-)(1)), Cd (1.07 microg g(-)(1)), Mn (4417 microg g(-)(1)), Ni (8.1 microg g(-)(1)), Co (5.8 microg g(-)(1)), Zn (1076 microg g(-)(1)), Cr (36.4 microg g(-)(1)), As (2.9 microg g(-)(1)), Se (6.3 microg g(-)(1)), Th (2.1 microg g(-)(1)) and Mo (0.762 microg g(-)(1)).     

Organochlorine and organophosphorous pesticide residues in ground water and surface waters of Kanpur, Uttar Pradesh, India

A survey undertaken in Kanpur, northern India, has shown the presence of high concentrations of both organochlorine and organophosphorous pesticides in the surface and ground water samples. Liquid-liquid extraction followed by GC-ECD was used for the determination of these compounds. Among the various pesticides analyzed, high concentrations of gamma-HCH (0.259 microg/l) and malathion (2.618 microg/l) were detected in the surface water samples collected from the River Ganges in Kanpur. In the ground water samples collected from the various hand pumps located in agricultural and industrial areas, apart from gamma-HCH and malathion, dieldrin was also detected. The maximum concentration values of gamma-HCH, malathion and dieldrin were 0.900, 29.835 and 16.227 microg/l, respectively. Especially, the concentration of malathion was found to be much higher than the EC water quality standards in the ground water samples from industrial area posing a high risk to the common people. Pesticides like DDE, DDT, aldrin, ethion, methyl parathion and endosulfan were not detected in both the surface and ground water samples.     

Interspecific variation in heavy metal body concentrations in biota of Sunderban mangrove wetland, northeast India

The coastal environment of West Bengal, recognized as the most diversified and productive ecosystem among all the maritime states of India, faces organic pollution from domestic sewage and urban and industrial effluents leading serious impacts on biota. The present paper aims at providing information on concentration level of heavy metals among the tissues of benthic polychaetes, bivalve molluscs and finfishes collected from Sundarban mangrove wetland, northeast coast of India. An overall common trend in bioaccumulation was revealed with the following decreasing order: Zn>Mn>Cu>Cr>Se>Hg with few exceptions. Both species dependent variability and temporal variations were pronounced. A high degree of organ specificity was evident in the bivalves where gill and mantle exhibited higher metal accumulation due to ion exchange property of the mucous layer covering these organs. Variability between closely related species is a reflection of different uptake rates, physiology and impact of environmental factors. The results of this analysis suggest that mollusks can play a significant role in trace metal trophic transfer studies, especially as their representatives are intertidally and subtidally ubiquitous.     

Heavy metal levels and esterase variations between metal-exposed and unexposed duckweed Lemna minor: field and laboratory studies

Environmental homogeneity is being continuously disturbed and affected by artificially introduced loads of chemical toxicants that also include heavy metals. The Tiljala wetlands of the eastern fringe of Calcutta, West Bengal (India) are a virtual sink for the deposition of urban and industrial wastes that get admixed with the aquatic environment. We have selected Lemna minor (duckweed), as a representative of the biota surviving therein for the present study. Concentrations of lead, cadmium, chromium, zinc, copper and mercury in the fronds of Lemna were measured to peep into the range of input of heavy metals in the duckweed subjects. Natural unexposed population of duckweed from a domestic pond in Batanagar area, 24 Parganas, West Bengal (India) was also found to accumulate similar concentrations of these metals when cultured in artificially contaminated water in the laboratory. The exposed individuals also exhibited polymorphism with respect to the loci of esterase, as compared to an unexposed control plants. Therefore, the present study suggests EST variations of L. minor to be a potential biomarker of heavy metal pollution.     

Tropical Coastal Organisms as Qualitative Indicators of Mercury and Organomercury for Sustainable Use of Living Resources

Organisms sensitive to ambient environment are used as bioindicators in monitoring pollution. The present investigation is designed to measure the extent of mercury and organomercury levels in selective biota of different trophic levels inhabiting in the coastal environment of Sunderban Biosphere Reserve, eastern part of India. The primary objective of this work is to provide baseline data for future environmental quality programme and to ascertain the suitability of these organisms to be used as bioindicator species of pollution. The seagrass (Porterasia coarctata), macrobenthos (polychaetes, gastropods and bivalve molluscs) and pelagic finfishes were collected from sites of different physiochemical characteristics. Concentration of total mercury was determined by cold vapour atomic absorption spectrophotometry technique (CVAAS) using a Perkin-Elmer 2380 AAS equipped with MHS 10.Both mercury and organomercury levels showed considerable interspecific and regional variations which reflected the feeding strategy of these animals and also the location of stations. The bivalve molluscs showed a high degree of organ-specificity in accumulation which might be attributed to the ion exchange activity of mucous membrane covering gill and mantle. Mercury levels in various compartments did not reveal any regular temporal variations but showed a slight increase in the late monsoon months indicating the apparent influence of river run-off and reduction in salinity in the ambient medium. A continuous monitoring programme is recommended in order to clarify the present trend and to establish the studied organisms as indicator species.     

Biota-sediment accumulation factors for Dechlorane Plus in bottom fish from an electronic waste recycling site, South China

Biota-sediment accumulation factors (BSAFs) for Dechlorane Plus (DP), a highly chlorinated flame retardant, were determined in three bottom fish species, i.e., crucian carp, mud carp, and northern snakehead from an electronic waste recycling site in South China. The average BSAFs are 0.007, 0.01, and 0.06 for syn-DP, and 0.003, 0.025, and 0.001 for anti-DP in crucian carp, mud carp, and northern snakehead, respectively, suggesting low bioaccumulation potential of DP isomers in these fish. However, the bioaccumulation factors (BAFs) determined previously in the same sample set indicated that both DP isomers were highly bioaccumulative (BAFs>5000) in most of the samples. This implies that BSAF values may be inherently inconsistent affecting their reliability as a bioaccumulation indicator. The BSAFs for DP isomers are two orders of magnitude lower than those (average of 0.43-2.28) for extremely hydrophobic polychlorinated biphenyls (CBs 199, 203, 207 and 208), but are comparable to those (average of 0.0001-0.009) for decabromodiphenyl ether (BDE 209) determined in the same sample set. Despite of the different chemical structures of the three compound classes, significantly negative correlations between logarithm of octanol-water partition coefficients (log K(OW)s) and BSAFs of these chemicals were found, indicating that hydrophobicity is one of the key factors influencing the bioaccumulation of these compounds.     

Biota-sediment accumulation factors for Dechlorane Plus in bottom fish from an electronic waste recycling site,South China

Biota-sediment accumulation factors (BSAFs) for Dechlorane Plus (DP), a highly chlorinated flame retardant, were determined in three bottom fish species, i.e., crucian carp, mud carp, and northern snakehead from an electronic waste recycling site in South China. The average BSAFs are 0.007, 0.01, and 0.06 for syn-DP, and 0.003, 0.025, and 0.001 for anti-DP in crucian carp, mud carp, and northern snakehead, respectively, suggesting low bioaccumulation potential of DP isomers in these fish. However, the bioaccumulation factors (BAFs) determined previously in the same sample set indicated that both DP isomers were highly bioaccumulative (BAFs > 5000) in most of the samples. This implies that BSAF values may be inherently inconsistent affecting their reliability as a bioaccumulation indicator. The BSAFs for DP isomers are two orders of magnitude lower than those (average of 0.43–2.28) for extremely hydrophobic polychlorinated biphenyls (CBs 199, 203, 207 and 208), but are comparable to those (average of 0.0001–0.009) for decabromodiphenyl ether (BDE 209) determined in the same sample set. Despite of the different chemical structures of the three compound classes, significantly negative correlations between logarithm of octanol–water partition coefficients (log K_OWs) and BSAFs of these chemicals were found, indicating that hydrophobicity is one of the key factors influencing the bioaccumulation of these compounds.     

Environmental fate of alkylphenols and alkylphenol ethoxylates--a review

Alkylphenol ethoxylates (APEs) are widely used surfactants in domestic and industrial products, which are commonly found in wastewater discharges and in sewage treatment plant (STP) effluents. Degradation of APEs in wastewater treatment plants or in the environment generates more persistent shorter-chain APEs and alkylphenols (APs) such as nonylphenol (NP), octylphenol (OP) and AP mono- to triethoxylates (NPE1, NPE2 and NPE3). There is concern that APE metabolites (NP, OP, NPE1-3) can mimic natural hormones and that the levels present in the environment may be sufficient to disrupt endocrine function in wildlife and humans. The physicochemical properties of the APE metabolites (NP, NPE1-4, OP, OPE1-4), in particular the high K(ow) values, indicate that they will partition effectively into sediments following discharge from STPs. The aqueous solubility data for the APE metabolites indicate that the concentration in water combined with the high partition coefficients will provide a significant reservoir (load) in various environmental compartments. Data from studies conducted in many regions across the world have shown significant levels in samples of every environmental compartment examined. In the US, levels of NP in air ranged from 0.01 to 81 ng/m3, with seasonal trends observed. Concentrations of APE metabolites in treated wastewater effluents in the US ranged from < 0.1 to 369 microg/l, in Spain they were between 6 and 343 microg/l and concentrations up to 330 microg/l were found in the UK. Levels in sediments reflected the high partition coefficients with concentrations reported ranging from < 0.1 to 13,700 microg/kg for sediments in the US. Fish in the UK were found to contain up to 0.8 microg/kg NP in muscle tissue. APEs degraded faster in the water column than in sediment. Aerobic conditions facilitate easier further biotransformation of APE metabolites than anaerobic conditions.     

Development and application of simple pharmacokinetic models to study human exposure to di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP)

In a published controlled dosing experiment, a single individual consumed 5 mg each of labeled di-n-butyl phthalate (DnBP) and diisobutyl phthalate (DiBP) on separate occasions and tracked metabolites in his blood and urine over 48 h. Data from this study were used to structure and calibrate simple pharmacokinetic (PK) models for these two phthalates, which predict urine and blood metabolite concentrations with a given phthalate intake scenario (times and quantities). The calibrated models were applied to a second published experiment in which 5 individuals fasted over the course of a 48-h weekend (bottled water only), and their full urine voids were captured and measured for DnBP and DiBP metabolites. One goal of this model application was to confirm the validity of the calibrated models — their validity would be demonstrated if a profile of intakes could be found which adequately duplicated the metabolite concentrations measured in the urine. A second goal was to study patterns of exposure for this group. It was found that all metabolites could be duplicated very well with individual-specific “best-fit” intake scenarios, with one exception. It appears that the model predicted much lower concentrations of the metabolite, 3carboxy-mono-propylphthalate (MCPP), than were observed in all individuals. Modeled as a metabolite of DnBP, this suggests that DnBP was not the major source of MCPP in the urine. For all 5 individuals, the reconstructed dose profiles of the two phthalates were similar: about 6 small bolus doses per day and an intake of about 0.5 μg/kg-day. The intakes did not appear to be associated with diary-reported activities (personal hygiene and medication) of the participants. The modeled frequent intakes suggested one (or both) of two possibilities: ongoing exposures such as an inhalation exposure, or no exposure but rather an ongoing release of body stores of the phthalate metabolites from past exposures.     

Urinary phthalate metabolite and bisphenol A associations with ultrasound and delivery indices of fetal growth

Growth of the fetus is highly sensitive to environmental perturbations, and disruption can lead to problems in pregnancy as well as later in life. This study investigates the relationship between maternal exposure to common plasticizers in pregnancy and fetal growth. Participants from a longitudinal birth cohort in Boston were recruited early in gestation and followed until delivery. Urine samples were collected at up to four time points and analyzed for concentrations of phthalate metabolites and bisphenol A (BPA). Ultrasound scans were performed at four time points during pregnancy for estimation of growth parameters, and birthweight was recorded at delivery. Growth measures were standardized to a larger population. For the present analysis we examined cross-sectional and repeated measures associations between exposure biomarkers and growth estimates in 482 non-anomalous singleton pregnancies. Cross-sectional associations between urinary phthalate metabolites or BPA and growth indices were imprecise. However, in repeated measures models, we observed significant inverse associations between di-2-ethylhexyl phthalate (DEHP) metabolites and estimated or actual fetal weight. An interquartile range increase in summed DEHP metabolites was associated with a 0.13 standard deviation decrease in estimated or actual fetal weight (95% confidence interval = − 0.23, − 0.03). Associations were consistent across different growth parameters (e.g., head circumference, femur length), and by fetal sex. No consistent associations were observed for other phthalate metabolites or BPA. Maternal exposure to DEHP during pregnancy was associated with decreased fetal growth, which could have repercussive effects.     

Association of serum concentration of organochlorine pesticides with dietary intake and other lifestyle factors among urban Chinese women

Concerns about the carcinogenic and endocrine-disrupting characteristics of organochlorine pesticides (OCPs) have led to a global ban on OCP use. However, OCPs persist in the environment for decades because of their long half-life. We evaluated serum levels of OCPs and their correlations with usual dietary intake and other lifestyle factors among 250 healthy women who participated as controls in the Shanghai Breast Cancer Study. Serum levels of hexachlorocyclohexane isomers (alpha-HCH, beta-HCH, gamma-HCH), dichloro-di-phenyl-trichloroethane (DDT) isomers (p,p'-DDE and p,p'-DDT), hexachlorobenzene (HCB), trans-nonachlor (TNC), and eight polychlorinated biphenyls (PCB) congeners (IUPAC no. 74, 118, 138, 153, 170, 180, 183, and 187) were measured. Lifestyle factors and usual dietary habits over the past 5 years were assessed through an in-person interview. With the exception of PCB, total OCP levels in our study population were significantly higher than those observed in other countries. Age, income, body mass index, waist-to-hip ratio, number of pregnancies, and/or total duration of breastfeeding were all significantly correlated with all types of OCPs. Of the 20 food groups evaluated, correlations with serum total OCPs were observed for eggs (r=0.13), fresh beans (r=-0.17), tea (r=0.14), and animal fat (r=0.18). Multiple regression analyses showed that age and animal fat intake were positively associated with serum total level OCPs, while leafy vegetable and fresh bean consumption was negatively associated with OCPs level. Our study suggests that dietary intake may be an important contributor of serum levels of OCPs in Chinese women.     

Organohalogenated pollutants in human serum from Iassy, Romania and their relation with age and gender

Human serum samples (n=142) from Iassy county (Eastern Romania) collected in 2005 were analyzed for p,p'-DDT and its metabolites, hexachlorobenzene, hexachlorocyclohexane (HCH) isomers, chlordane and metabolites and 14 polychlorinated biphenyl (PCB) congeners. In all samples, p,p'-DDE (principal metabolite of p,p'-DDT) and beta-HCH (most persistent HCH isomer) were the most abundant organochlorine pesticides (OCPs) with median concentrations of 1975 and 923 ng/g lipid weight (lw), respectively. Hexachlorobenzene and p,p'-DDT were also detected in all samples, but at a lower median concentration of 30 and 340 ng/g lw, respectively. The large variation of the ratio p,p'-DDT/p,p'-DDE (range between 0.02 and 0.80) suggests various degrees of exposure to DDT, including recent exposure, at least to some subgroups of the population. Chlordane and its metabolites were in most cases close to the limit of quantification suggesting a very low use of chlordane formulations in Eastern Romania. Unexpectedly, PCBs were present in all samples at sometimes considerable levels (up to 4970 ng/g lw for sum of 14 PCB congeners) indicating a higher exposure of the Romanian population than previously reported. The PCB profile consisted of persistent congeners such as 138, 153, 170 and 180 which contributed for approximately 75% to the sum PCBs. Concentrations of most pollutants correlated significantly with age (r>0.86, p<0.01). Except for p,p'-DDT and gamma-HCH, the mean levels of OCPs in females were statistically higher than in males, while, except for octa-CBs, no gender differences were found for PCBs. Levels of p,p'-DDE, penta-CBs, hexa-CBs and hepta-CBs were significantly higher in individuals with a rural main residence. In a pooled serum sample, 6 polybrominated diphenyl ether (PBDE) congeners were measured at a level of 1.04 ng/g lw. Compared to results available from Central and Eastern European countries, human serum samples from Romania contained higher levels of contamination. This emphasizes that an extensive and rigorous program for the monitoring of OCPs and PCBs in Romanian population is highly needed in the light of possible adverse health effects acknowledged for these pollutants.