Associations between organochlorine pesticides and cognition in U.S. elders: National Health and Nutrition Examination Survey 1999-2002

There is limited evidence about whether background exposure to organochlorine pesticides is related to impairment of cognitive function in general populations. This study was performed to investigate cross-sectional associations between serum concentrations of organochlorine pesticides and cognitive function, a predictor of dementia, among U.S. elders without overt dementia. Study subjects were 644 elders aged 60-85, participating in the National Health and Nutrition Examination Survey 1999-2002. We selected 6 organochlorine pesticides (p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethylene (DDE), trans-nonachlor, oxychlordane, heptachlor epoxide, and β-hexachlorocyclohexane) which were commonly detected in current general population. Cognitive function was assessed with the Digit-Symbol Substitution Test. All 6 compounds showed statistically significant or marginally significant inverse associations with cognitive score after adjusting for covariates including education levels. The strongest association was observed with p,p'-DDT. With the outcome of low cognitive score defined as <25th percentile, elders in the highest quartile of p,p'-DDT, p,p'-DDE, and β-hexachlorocyclohexane had 2 to 3 times higher risks than those in the lowest quartile. In particular, when their concentrations were further divided with the cutoff points of 90th and 95th percentiles, p,p'-DDT in the highest 5th percentile showed 6.5 (95% confidence interval: 2.6-16.3) times higher risk of low cognitive score. On the other hand, non-persistent pesticides like organophosphates or pyrethroid showed little association with this cognitive score. The potential role of background exposure to organochlorine pesticides in the development of dementia should be explored in future prospective studies and in-vitro/in-vivo experimental studies.

Distribution and uptake pathways of organochlorine pesticides in greenhouse and conventional vegetables

The application of greenhouse vegetable cultivation has dramatically expanded worldwide during the last several decades. However, little information is available on the distribution and uptake of pesticides in greenhouse vegetables. To bridge this knowledge gap, the present study was initiated to investigate the distribution and uptake of organochlorine pesticides (OCPs) in vegetables from plastic greenhouse and conventional cultivation methods. The uptake pathways of OCPs were not significantly different between these two cultivation methods. The arithmetic means of OCP concentrations in greenhouse vegetables were higher than those in conventional vegetables, although there was no significant difference. This small difference raised the concern of whether the tiny difference could be magnified to a significant difference by bioaccumulation in the food chain. The issue should be addressed by a well-designed scheme in future studies.

The fate of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in water from Poyang Lake, the largest freshwater lake in China

The fate of polycyclic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in the water columns from Poyang Lake was studied. The total concentrations of OCPs and PAHs were 19.10-111.78 ng L(-1) and 5.56-266.1 ng L(-1), respectively. Among OCPs, endosulfans, chlordanes, and HCHs accounted for 21.96%, 24.6% and 24.65%, and were the predominant pollutants. Results suggested that the main sources of DDTs were residue from technical DDTs and dicofol, as well as antifouling paints for ships, while for HCHs, the main sources included long-distance transmission, agriculture activities and the combination of industrial products with separate lindane in use. As for PAHs, the predominance of lower molecular weight congeners demonstrated that petroleum and the combustion products of fuel oil, as well as other pyrogenic sources, contributed to the main input of PAHs in the Poyang region. The vehicle emissions were mostly from diesel engines. Moreover, HCH, DDT and BaP concentrations in water of Poyang Lake were all below the threshold values.

Relationship between serum concentrations of persistent organic pollutants and markers of insulin resistance in a cohort of women with a history of gestational diabetes mellitus

The aim of the present study was to assess the relationship between serum concentrations of several persistent organic pollutants and insulin resistance markers in a cohort of women with a history of gestational diabetes mellitus. ∑POPs was computed as the sum of individual serum POP concentrations. No statistically significant associations were found between levels of any POP and fasting glucose. However, polychlorinated biphenyl (PCB) congeners 138 and 180 were positively associated with 2-h glucose levels and PCB 180 also with fasting immunoreactive insulin (IRI). We also found a positive association of p,p'- dichlorodiphenyldichloroethylene (p,p'- DDE), PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs with 2-h IRI. Serum concentrations of PCBs (138, 153, and 180), hexachlorobenzene, and ∑POPs were also positively associated with homeostasis model assessment (HOMA2-IR) levels. Moreover, p,p'- DDE, PCBs (138, 153 and 180), hexachlorobenzene, and ∑POPs were negatively associated with Insulin Sensitivity Index (ISI-gly) levels. No significant association was found between glycated hemoglobin and the concentrations of any POP. The removal of women under blood glucose lowering treatment from the models strengthened most of the associations previously found for the whole population. Our findings suggest that exposure to certain POPs is a modifiable risk factor contributing to insulin resistance.

Persistent organochlorine pesticides in internal organs of coypu, Myocastor coypus

A highly selective and sensitive method based on gas chromatography-tandem mass spectrometry (GC-MS/MS) to identify and quantify persistent organochlorine pesticides, (18 compounds including primary compounds and metabolites), in animal internal organs (kidneys, liver, and brain) has been developed. Tandem mass spectrometric conditions were individually optimized for each target compound in Multiple Reaction Monitoring (MRM) mode to obtain maximum sensitivity. Prior to instrumental analysis, a sample preparation method based on matrix solid phase dispersion (MSPD) followed by acidic digestion with sulfuric acid to reduce matrix co-extractives was employed. Analyses of real samples were carried out on coypus (Myocastor coypus) from the autumn slaughter of 19 animals. In the analyzed samples, three of the target compounds, namely DDE-pp' (DDT metabolite), HCB and lindane, were detected. Their concentration levels fell in the ranges of 0.003-0.007, 0.003-0.025, and 0.003-0.021 mg kg(-1) (0.005, 0.010, and 0.010 mg kg(-1) on average) in the case of DDE-pp', HCB and lindane, respectively. Although low quantities of organochlorine pesticides do not pose an immediate danger to consumers' health, they should be of public health concern considering long-term, low-dose exposure.

Concentrations of persistent organic pollutants in California women's serum and residential dust

BACKGROUND

Humans are exposed to persistent organic pollutants (POPs) through various routes, including consumption of contaminated food and accidental ingestion of settled dust.

OBJECTIVES

We aimed to identify key routes of exposure to organochlorine pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in California women of reproductive age.

METHODS

Blood was collected from 48 mothers participating in the California Childhood Leukemia Study from 2006 to 2007 and analyzed for POPs using gas chromatography-mass spectrometry. Multivariable linear regression models of natural-log transformed serum concentrations were used to identify determinants of exposure from available questionnaire information on dietary habits, reproductive history, and demographic characteristics, as well as vacuum cleaner dust-POP levels.

RESULTS

After adjusting for blood lipid levels, age, body mass index, cumulative lactation, and sampling date, serum concentrations of multiple major PCBs were positively associated with fish consumption, but not dust-PCB levels. After adjusting for blood lipid levels, Hispanic ethnicity, country of origin, and household annual income, serum concentrations of multiple major PBDEs were positively associated with dust-PBDE levels.

CONCLUSIONS

Our findings suggest that the relative contribution of specific exposure routes to total POP intake varies by chemical class, with dust being a relatively important source of PBDEs and diet being a relatively important source of PCBs.

The spatial distribution of organochlorine pesticides and halogenated flame retardants in the surface sediments of an Arctic fjord: the influence of ocean currents vs. glacial runoff

Selected organochlorine pesticides (OCs) and halogenated flame retardants (HFRs) were analyzed in surficial fjord sediments collected down the length of Kongsfjorden, Svalbard in the Norwegian high Arctic. Hexachlorocyclohexane (α-HCHs) was found to be the most abundant OC in the sediment, followed by BDE-209>chlordane>α-endosulfan>Dechlorane Plus (anti-DP)>trifluralin concentration ranges were high over the relatively small study area of the fjord (e.g. ∑HCH: 7.2-100 pg g(-1) dry weight (dw)), with concentrations broadly similar to, or lower than, measurements conducted in other parts of the Arctic. Concentrations of legacy OCs, including both HCH isomers and chlordane showed a decreasing trend from the outer, seaward end of the fjord to the inner, glacier end of the fjord. Conversely, sediment concentrations of α- and β-endosulfan (0.1-12.5 pg g(-1) dw) increased from the outer fjord to the inner fjord. This contrasting pattern may be attributed to the influence of historical vs. contemporary sources of these chemicals to the fjord area, whereby the North Atlantic/West Spitzbergen oceanic current dominates the transport and input of the legacy OCs, whereas atmospheric deposition and meltwater runoff from the glaciers influence the inner fjord sediments for endosulfan. Interestingly, BDE-209 and Dechlorane Plus did not reveal any clear spatial trend. It is plausible that both glacial runoff and oceanic current end members are playing a role in introducing these chemicals to the fjord sediments. The relatively low fractional abundance of the syn-DP isomer (fsyn), however, indicates the long-range transport of this chemical to this Arctic site.

Levels and patterns of organochlorine pesticides and their degradation products in rainwater in Kibaha Coast Region, Tanzania

The levels and patterns of organochlorine pesticides and degradation products in rainwater samples collected in relation to a contaminated site in Kibaha district, Tanzania were investigated. The compounds detected in the samples by GC-MS and isotope dilution methodology included DDT, DDE, DDD, HCHs, dieldrin, heptachlor, chlordane, endrin and hexachlorobenzene. The concentrations of total DDT and total HCH ranged 0.005-3200μgL(-1) and 0.01-170μgL(-1), respectively and they indicated input of significantly non-degraded technical mixtures. The highest concentrations for other compounds ranged 0.001-1.3μgL(-1). The highest concentrations were found in samples collected in the vicinity of the contaminated site and the concentrations at other points showed a general even distribution suggesting repeated volatilization and deposition mechanisms. The strong positive correlations in the concentrations of the compounds indicated a common source. A decrease in concentrations with time was indicated, although the decrease was not significant during the period of sampling. The findings indicate risks and concerns for public and environmental health.

Human dietary intake of organohalogen contaminants at e-waste recycling sites in Eastern China

This study reports concentrations and human dietary intake of hexabromocyclododecanes (HBCDs), polychlorinated biphenyls (PCBs) as well as selected "novel" brominated flame retardants (NBFRs) and organochlorine pesticides, in ten staple food categories. Samples were sourced from areas in Taizhou City, eastern China, where rudimentary recycling and disposal of e-waste is commonplace, as well as from nearby non-e-waste impacted control areas. In most instances, concentrations in foods from e-waste recycling areas exceeded those from control locations. Concentrations of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis-(2-ethylhexyl)-3,4,5,6-tetrabromophthalate (BEH-TBP) in samples from e-waste sites were 3.09-62.2ng/g and 0.81-16.3ng/g lipid weight (lw), respectively; exceeding consistently those in foods acquired from control sites by an order of magnitude in many cases. In contrast, while concentrations of HBCD in some foods from e-waste impacted areas exceed those from control locations; concentrations in pork, shrimp, and duck liver are higher in control samples. This highlights the potential significance of non-e-waste sources of HBCD (e.g. building insulation foam) in our study areas. While concentrations of DDT in all foods examined except pork were higher in e-waste impacted samples than controls; our exposure estimates were well below the provisional tolerable daily intake of 0.01mg/kgbw/day derived by the Joint FAO/WHO Meeting on Pesticide Residues. Concentrations of ΣPCBs resulted in exposures (650 and 2340ng/kgbw/day for adults and children respectively) that exceed substantially the Minimal Risk Levels (MRLs) for ΣPCBs of 20ng/kgbw/day derived by the Agency for Toxic Substances & Disease Registry. Moreover, when expressed in terms of dioxin-like toxicity equivalency based on the four dioxin-like PCBs monitored in this study (DL-PCBs) (PCB-105, 118, 156, and 167); concentrations in e-waste impacted foods exceed limits set by the European Union in 6 of the 8 food groups studied and result in dietary exposures for children (10.2pgTEQ/kgbw/day) that exceed the WHO tolerable daily intake of 1-4pgTEQ/kgbw/day.

Air-soil exchange of organochlorine pesticides in a sealed chamber

So far little is known about air-soil exchange under any sealed circumstances (e.g., in plastic and glass sheds), which however has huge implications for the soil-air-plant pathways of persistent organic pollutants including organochlorine pesticides (OCPs). A newly designed passive air sampler was tested in a sealed chamber for measuring the vertical concentration profiles of gaseous phase OCPs (hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs)). Air was sampled at 5, 15, and 30 cm above ground level every 10th day during a 60-day period by deploying polyurethane foam cylinders housed in acrylonitrile butadiene styrene-covered cartridges. Concentrations and compositions of OCPs along the vertical sections indicated a clear relationship with proximity to the mixture of HCHs and DDTs which escapes from the soils. In addition, significant positive correlations were found between air temperatures and concentrations of HCHs and DDTs. These results indicated revolatilization and re-deposition being at or close to dynamic pseudo-equilibrium with the overlying air. The sampler used for addressing air-soil exchange of persistent organic pollutants in any sealed conditions is discussed.

Chiral signature of α-HCH and o,p'-DDT in the soil and grass of the Central Tibetan Plateau, China

Enantiomeric fraction (EF) of organochlorine pesticides (OCPs) has been used as a signature for tracing the source and following pathways. The chiral analysis was performed for α-HCH and o,p'-DDT in paired soil and grass samples from the Central Tibetan Plateau (CTP), a unique background region. In the case of α-HCH, excess of (-) α-HCH was predominant in 83.3% of soil samples, and 80% of grass samples showed excess of (+) enantiomer. For o,p'-DDT, 90.9% of grass samples showed excess of (-) o,p'-DDT while 50% of soil samples showed excess of the (-) enantiomer. A correlation between EFs of soil and grass was not observed for either compound. The EFs of both compounds were correlated with soil concentration and with change of sampling altitude, within EFs being lower than racemic. However, these trends were not found in grass. Our study provides a database of EFs and signatures for OCPs in the CTP, one background region of the world.

Levels, compositions and distributions of organochlorine pesticide residues in soil 5-14 years after clean-up of former storage sites in Tanzania

The levels, compositions and distributions of organochlorine pesticides and metabolites were determined in soil samples collected 5-14 years after clean-up was carried out at seven contaminated sites in Tanzania. Samples were collected from various depths (5-10 cm, 30 cm, and 50 cm for most sites and up to 300 cm for one site. Determination of the analytes was performed using a high resolution GC-MS and isotope dilution technology. DDT, DDD, DDE, HCH isomers, aldrin, dieldrin, endrin, endosulfans, chlordanes and heptachlor were the major compounds detected. The concentrations of total DDT and total HCH were up to 250000 and 164,000 mg kg(-1), respectively, while the highest concentrations for other compounds ranged from 29 to 3300 mg kg(-1). The results indicated that there were no significant degradations/transformations of the pesticides for most of the sites. The highest concentrations of the compounds were mostly found in surface soil samples and there were variations in distribution among the sampling depths. The results indicate risks and concerns for public health and the environment.

Prepubertal organochlorine pesticide concentrations and age of pubertal onset among Russian boys

BACKGROUND

In animal studies, organochlorine pesticide (OCP) exposure alters pubertal development; however, epidemiological data are limited and inconsistent.

OBJECTIVE

To evaluate the associations of serum OCP concentrations [hexachlorobenzene (HCB), β-hexachlorocyclohexane (β-HCH), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE)] with male pubertal onset.

METHODS

In Chapaevsk, Russia, a town environmentally contaminated with OCPs, 350 8-9 year old boys with measured OCPs were enrolled during 2003-2005 and were followed annually for eight years. We evaluated three measures of pubertal onset: testicular volume (TV)>3 mL in either testis, or stage 2 or greater for genitalia (G2+), or pubic hair (P2+). We used multivariable interval-censored models to evaluate associations of OCPs (quartiles) with physician-assessed pubertal onset.

RESULTS

In adjusted models, boys with higher HCB concentrations had later mean ages of TV>3 mL and P2+ (but not G2+). Mean age at attaining TV>3 mL was delayed 3.6 (95% CI: -2.6, 9.7), 7.9 (95% CI: 1.7, 14.0), and 4.7 months (95% CI: -1.4, 10.9) for HCB Q2, Q3, and Q4, respectively, compared to Q1 (trend p: 0.06). Boys with higher HCB concentrations reached P2+ 0.1 months earlier (95% CI: -5.8, 5.6) for Q2, 4.7 months later (95% CI: -1.0, 10.3) for Q3 and 4.6 months later (95% CI: -1.1, 10.3) for Q4 compared to Q1 (trend p: 0.04). There were no associations of serum β-HCH and p,p'-DDE concentrations with age of pubertal onset.

CONCLUSION

Higher prepubertal serum HCB concentrations were associated with later age of gonadarche and pubarche.

Associations of accumulated exposure to persistent organic pollutants with serum lipids and obesity in an adult cohort from Southern Spain

The aim of this research was to study the association of the accumulated human exposure to persistent organic pollutants with serum lipid levels and obesity, in a cohort of 298 adults. In the multivariable analyses, HCB concentrations evidenced a significant quadratic association with levels of total cholesterol, HDL, LDL, and total serum lipids. Likewise, PCBs 138 and 180 were associated with triglycerides and total serum lipids, and PCB 153 with LDL. HCB, p,p'-DDE, and β-HCH showed quadratic associations with BMI. All quadratic models showed a positive trend at low exposure levels, while the slope decreased or even became negative at higher exposure levels. Additionally, PCB 138 was positively associated with BMI but in a linear manner. Our results suggest a potential relationship between historical POP exposure and serum lipids/obesity, which followed a non-linear pattern in most cases.

Socioeconomic development as a determinant of the levels of organochlorine pesticides and PCBs in the inhabitants of Western and Central African countries

Several studies of environmental samples indicate that the levels of many persistent organic pollutants (POPs) are increasing in Africa, but few studies have been conducted in humans. Simultaneously, many African countries are experiencing a rapid economic growth and implementing information and communication technologies (ICT). These changes have generated high amounts of electronic waste (e-waste) that have not been adequately managed. We tested the hypothesis that the current levels of two main classes of POPs in Western and Central African countries are affected by the degree of socioeconomic development. We measured the levels of 36 POPs in the serum of recent immigrants (N=575) who came from 19 Sub-Saharan countries to the Canary Islands (Spain). We performed statistical analyses on their anthropometric and socioeconomic data. High median levels of POPs were found in the overall sample, with differences among the countries. Organochlorine pesticide (OCP) and polychlorinated biphenyl (PCB) levels increased with age. People from low-income countries had significantly higher OCP levels and much lower PCB levels than those from high-income countries. We found a significant association between the implementation of ICT and PCB contamination. Immigrants from the countries with a high volume of imports of second-hand electronic equipment had higher PCB levels. The economic development of Africa and the e-waste generation have directly affected the levels of POPs. The POP legacies of these African populations most likely are due to the inappropriate management of the POPs' residues.

Spatial and seasonal distribution of organochlorine pesticides in the sediments of the Yangtze Estuary

The spatial and seasonal distribution of organochlorine pesticides (OCPs) in the sediments of the Yangtze Estuary was investigated. The total concentration of 19 OCPs (∑OCPs), including α-HCH, β-HCH, γ-HCH, δ-HCH, o, p'-DDE, p, p'-DDE, o, p'-DDD, p, p'-DDD, o, p'-DDT, p, p'-DDT, heptachlor, aldrin, heptachlor epoxide (Isomer B, Isomer A), endosulfan I, dieldrin, endrin, endosulfan II and methoxychlor, in the surface sediments ranged from 0.4 to 82.1 ng g(-1) d.w. The mean values of the ∑OCPs were 8.5 ± 8.3 ng g(-1) d.w., 26.7 ± 12.1 ng g(-1) d.w., 40.5 ± 18.2 ng g(-1) d.w., and 13.0 ± 11.2 ng g(-1) d.w. for August 2010, November 2010, February 2011 and May 2011, respectively. The highest concentration of OCPs was detected at the river-sea boundary because of the intense resuspension and redeposition of sediments in this area. The OCPs preferred to accumulate in the inner estuary, rather than in the offshore area in the dry season, whereas the opposite occurred in the flood season. This phenomenon was related to the seasonal changes of the Changjiang diluted water (CDW). OCPs in the offshore area were controlled by the ocean currents and the monsoon. There was a southward increase for the OCP deposition in the offshore area in the winter. This increase resulted from the influences of the southward Yellow Sea coastal current and the East China Sea coastal current, as well as the northwest wind in winter. The Three Gorges Dam had an impact on HCH composition by changing the sediment redistribution during the deposition process.

Blood pressure in relation to contamination by polychlorobiphenyls and organochlorine pesticides: Results from a population-based study in the Canary Islands (Spain)

BACKGROUND

Epidemiological studies have reported significant associations between exposure to persistent organic pollutants (POPs) and increased blood pressure (BP). Environmental exposure to POPs, mainly organochlorine pesticides, is of concern to the population of the Canary Islands, who display a high prevalence of diseases associated with hypertension such as metabolic syndrome, obesity and cardiovascular disease.

OBJECTIVE

We performed this population-based study in a representative population sample from this archipelago to evaluate whether serum levels of selected POPs could be considered as hypertension risk factors.

METHODS

BP and several other well-known factors related to hypertension (gender, age, smoking, BMI, and total lipids) were recorded in 428 adult participants from the Canary Islands Nutritional Survey. In total, 28 POPs (including 18 polychlorinated biphenyl (PCB) congeners and 10 organochlorine pesticides and metabolites) were measured in the serum of the population enrolled in this survey.

RESULTS

In total, 167 subjects (39%) demonstrated hypertension or used antihypertensive medication. We observed a positive association between systolic and diastolic BP and p,p'-DDE (r=0.222; p<0.001, and r=0.123; p=0.015, respectively). Conversely, an inverse association between systolic BP and aldrin was observed (r=-0.120; p=0.017). After adjusting for known confounders, only aldrin was inversely related to hypertension risk [OR: 0.28 (95% CI: 0.09-0.92); p=0.037]. After excluding subjects undergoing anti-hypertensive treatment, we also observed that aldrin was inversely associated with systolic BP in multivariate analyses, especially in men [OR: 0.126 (95% CI: 0.021-0.763); p=0.024].

CONCLUSION

Although it has been postulated that background POPs exposure may play a relevant role on elevated BP, we did not observed increased hypertension risk in relation to serum POPs in this cross-sectional study. Conversely, the cyclodiene pesticide aldrin was negatively associated with hypertension, suggesting that cyclodienes could exert an effect opposite of the DDT metabolites. These findings agree with other previous works indicating that POPs may induce divergent actions on BP and suggest that the direction of the association between BP and POPs could be dependent on the chemical structure as well as concentration of the evaluated POP. Prospective studies are needed to clarify the effect exerted by POPs on BP.

Prospective associations between persistent organic pollutants and metabolic syndrome: a nested case-control study

OBJECTIVE

Exposure to persistent organic pollutants (POPs) has recently been linked to metabolic syndrome (MetS) and some MetS components. However, prospective evidence in humans is scarce, and the nature of the dose-response relationship is unclear. We evaluated the association between POPs and MetS using a nested-case control study within a community-based Korean cohort.

METHOD

The study subjects were 64 patients newly diagnosed with MetS during a 4-year follow-up, and the controls were 182 subjects without MetS. Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were measured in stored serum collected at baseline.

RESULTS

The concentrations of most PCBs and some OCPs such as β-hexachlorocyclohexane, hexachlorobenzene, oxychlordane, and heptachlor epoxide predicted the risk for MetS. The POP exposure and MetS showed an inverted U-shaped or a linear association with plateau rather than a linear dose-response association. When the summary measure of the PCBs and OCPs was used, the adjusted odds ratios (ORs) across the quartiles of the summary measure were 1.0, 1.3, 3.8 (95% confidence interval, 1.3-10.7), and 2.1 (Pquadratic=0.013) after adjusting for potential confounders. In the analyses of each of the five MetS components, POP exposure was mainly associated with an increased risk for glucose and lipid metabolism disturbances.

CONCLUSION

This study demonstrated that chronic exposure to a mixture of PCBs and OCPs can increase the risk for MetS within the low-dose background exposure range of POPs. As the findings of this study suggest a nonmonotonic dose-response relationship, in vitro and in vivo experimental studies are needed to understand the underlying mechanisms.

Assessment of the levels of polycyclic aromatic hydrocarbons and organochlorine contaminants in bottlenose dolphins (Tursiops truncatus) from the Eastern Atlantic Ocean

The concentrations of 18 polychlorinated biphenyls (PCBs), 23 organochlorine pesticides (OCPs), and 16 polycyclic aromatic hydrocarbons (PAHs) were determined in the blubber and liver of 27 bottlenose dolphins (Tursiops truncatus) stranded along the Canary Islands coasts from 1997 to 2011. DDTs (mean of 60,960 and 445 ng/g lw., respectively) and PCBs (mean of 47,168 and 628 ng/g lw., respectively) were the predominant compounds in both tissues. Among PCBs the highly chlorinated PCB 180, 153 and 138 were the predominant congeners. We found a p,p'-DDE/∑DDTs ratio of 0.87 in blubber and 0.88 in liver, which is indicative of DDT ageing. All the samples showed detectable values of any of the 16 PAH studied. Phenanthrene was the most frequently detected and at the highest concentration. According to our results, concentrations of OCPs, and especially PCBs, are still at toxicologically relevant levels in blubber of bottlenose dolphins of this geographical area.

Prenatal exposure to organochlorine pesticides and infant birth weight in China

In utero exposure to organochlorine pesticides (OCPs) is thought to be potentially harmful to fetal development. We aimed to investigate the associations of maternal and cord serum OCPs levels with infant birth weight in China. In this study, we measured serum levels of 18 OCPs in 81 mother-infant pairs, including DDT, hexachlorocyclohexanes (BHC), hexachlorobenzene (HCB), heptachlors, chlordanes, endosulfan-I, and mirex using a high-resolution-gas-chromatography with high-resolution-mass-spectrometry method. We found that p,p'-DDE and β-BHC had the highest detection rate in both maternal and cord blood serum (97.2% and 96.7%, respectively), followed by HCB (93.0%, 51.7%), p,p'-DDT (88.7%, 36.7%), and p,p'-DDD (83.1%, 60.0%). Among all OCPs, the concentration of p,p'-DDE was the highest (mothers geometric mean (GM): 203.54ngg(-1), newborns GM: 116.14ngg(-1)), followed by HCB (70.62ngg(-1), 65.16ngg(-1)), and β-BHC (67.67ngg(-1), 33.39ngg(-1)). Multiple linear regression analyses showed that each 1ngg(-1) increment of cord serum p,p'-DDE, total DDT, and β-BHC was associated with a 0.10g, 0.10g, and 0.92g decrease in infant birth weight, respectively, and as the cord serum concentrations of p,p'-DDT, p,p'-DDD, HCB and mirex increased, the infant birth weight was also decreased, although the associations were not statistically significant due to the relatively small sample size. These results suggest that p,p'-DDE, β-BHC, and HCB were the predominant OCPs in the serum of Chinese pregnant women and cord blood of their newborns. Prenatal exposure to DDT, β-BHC, HCB, and mirex were associated with a decrease in birth weight, but these results need validation in larger sample-sized studies.

Organochlorine pesticide levels in maternal serum and risk of neural tube defects in offspring in Shanxi Province, China: a case-control study

Organochlorine pesticides (OCPs) in placental tissue have been reported to be associated with an increased risk for fetal neural tube defects (NTDs). Our case-control study was performed to explore the association between maternal serum OCP concentration and NTD risk in offspring. Serum samples were collected from 117 mothers who delivered NTD infants (case group) and 121 mothers who delivered healthy infants (control group). Only three of the 25 OCPs were detected in more than half of the maternal serum samples. The median concentration of total OCPs in the case group was significantly higher than that of the control group. However, no dose-response relationships between higher levels of any individual OCPs or total OCPs and the risk of NTDs or subtypes were observed in either the unadjusted binary unconditional logistic regression model or the model adjusted by potential confounders. We conclude that no clear association between maternal serum OCP residues and NTD risk in offspring was observed in this population.

CAPSULE

No clear association between maternal serum levels of organochlorine pesticides and risk of neural tube defects in offspring was observed for a Chinese population.

Effect of home food processing on chlordecone (organochlorine) content in vegetables

Decades after their use and their ban, organochlorine pesticides still pollute soil, water and food and lead to human and ecosystem exposure. In the case of chlordecone, human exposure is mainly due to the consumption of polluted food. We studied the effect of preparation and cooking in five vegetable products, three root vegetables (yam, dasheen and sweet potato) and two cucurbits (cucumber and pumpkin), among the main contributors to exposure to chlordecone in food in the French West Indies. Boiling the vegetables in water had no effect on chlordecone content of the vegetables and consequently on consumer exposure. The peel was three to 40-fold more contaminated than the pulp except cucumber, where the difference was less contrasted. The edible part is thus significantly less contaminated and peeling is recommended after rinsing to reduce consumer exposure, particularly for food grown in home gardens with contaminated soils. The type of soil had no consistent effect on CLD distribution but plot did. Peel and pulp composition (lipids and fibers) appear to partially account for CLD distribution in the product.

Multimatrix measurement of persistent organic pollutants in Mar Chiquita, a continental saline shallow lake

RAMSAR sites are determined by specific characteristics of the environment in terms of ecological productivity as well services for human development, but they are also one of the most threatened ecosystems. Thus, the objective of this work was to evaluate the dynamic of Persistent Organic Pollutants (POPs) in different biotic and abiotic matrixes of the RAMSAR site (wetlands with international importance), Mar Chiquita Lake. Sampling was performed according to land use (agricultural, urban, and industrial) at two stations: Laguna del Plata and Campo Mare. POPs were analyzed in superficial water (Sw), suspended particulate material (SPM), bottom sediment (Bs) and fish tissues (Odontesthes bonariensis). Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were analyzed by GC-ECD. HCHs, Endosulfans, DDTs, PCBs and PBDEs were found in all matrixes at both stations. The high persistence and transport processes are responsible for the occurrence of HCHs, DDTs and PCBs in Bs, SPM and fish tissues, even many years after their prohibition. PBDEs showed lower levels according to the scarcity of punctual sources in the area. Endosulfan showed variable amounts in agreement with application periods since this pesticide was used until a few years ago in this area. Finally, PCB levels overpassed the acceptable daily intake for human consumption being a risk for human health Thus, the present report confirms the occurrence of POPs in Mar Chiquita lake, alerting on the contribution of agricultural and urban pollutants in a RAMSAR site. Current results also raise concerns on biomagnification processes through the food web.

Concentrations and human health risk assessment of organochlorine pesticides in edible fish species from a Rift Valley lake-Lake Ziway, Ethiopia

Fish consumption is known to have several health benefits for humans. However, the accumulation of organic pollutants, like organochlorine pesticides (OCPs) could pose health hazards. Thus, OCPs in edible fish species (Oreochromis niloticus, Tilapia zillii, Carassius spp., and Clarias gariepinus) from Lake Ziway, an Ethiopian Rift Valley Lake were investigated to assess the potential human health hazards of these contaminants. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), chlordanes, and heptachlors were observed with ΣOCPs concentration ranging from 1.41 to 63.8 ng g(-1) ww. DDTs were the predominant contaminants (0.9 to 61.9 ng g(-1) ww), followed by HCHs. The predominance of DDTs may be attributed to their current use in vector control and contamination from past usage. The estimated daily intakes (EDIs) of OCPs from all fish species were much lower than the acceptable daily intakes (ADIs), indicating that consumption of fish is at little risk to human health at present. However, the cancer risk estimates in the area of concern and the hazard ratios (HRs) of HCHs, DDTs, and heptachlors exceeded the threshold value of one, indicating daily exposure to these compounds is a potential concern. This may result in a lifetime cancer risk greater than of 1 in 10(6).

Association of CYP1A1, CYP1B1 and CYP17 gene polymorphisms and organochlorine pesticides with benign prostatic hyperplasia

It is well established that steroidal hormones (testosterone and estrogen) increase benign prostatic hyperplasia (BPH) risk. Cytochrome P450 (CYP) enzymes especially CYP1A1, CYP1B1 and CYP17 metabolize these hormones. Apart from that, several endocrine disrupting organochlorine pesticides (OCPs) are reported to mimic the activity of these steroidal hormones. Therefore, functional polymorphisms in these genes and exposure to such pesticides may increase BPH risk further. Our study included 100 newly diagnosed BPH subjects and 100 age-matched healthy male controls. CYP1A1, CYP1B1 and CYP17 polymorphisms were studied using PCR-RFLP and allele-specific PCR method. OCP levels in blood were analyzed by gas chromatography (GC). Levels of p,p'-DDE and endosulfan α were found to be significantly higher amongst BPH subjects as compared to controls (p-values=0.001 and 0.03 respectively) and CYP17 polymorphism was observed to be significantly associated with BPH subjects as compared to controls (p-values=0.03), indicating that these factors may be important risk factors for BPH. However, further studies are required before unequivocal conclusion.