Multiple organochlorine pesticide exposures and measures of sex steroid hormones in adult males: Cross-sectional findings from the 1999-2004 National Health and Nutrition Examination Survey

BACKGROUND

Organochlorine pesticides are detectable in serum from most adults. Animal studies provide evidence of pesticide effects on sex hormones, suggesting that exposures may impact human reproductive function. Mounting evidence of sex differences in chronic diseases suggest that perturbations in endogenous sex hormones may influence disease risk. However, the association between organochlorine pesticide exposure and sex hormone levels in males across the lifespan is not well understood.

METHODS

We evaluated cross-sectional associations of lipid-adjusted serum concentrations of β-hexachlorocyclohexane, hexachlorobenzene, heptachlor epoxide, oxychlordane, dichlorodiphenyldichloroethylene (DDE), p,p'-dichlorodiphenyltrichloroethane (DDT), trans-nonachlor, and mirex in relation to sex steroid hormone levels [testosterone (ng/dL), sex hormone binding globulin (SHBG; nmol/L), estradiol (pg/mL), and androstanediol glucuronide (ng/dL)] in a sample of 748 males aged 20 years and older from the 1999-2004 cycles of the National Health and Nutrition Examination Survey (NHANES). Survey-weighted linear regression models were performed to estimate geometric means (GM) and their 95% confidence intervals (CIs) for quartiles of lipid-adjusted pesticide concentrations, adjusting for age, race, body mass index, serum lipids, smoking, education, and survey cycle.

RESULTS

Hexachlorobenzene concentration was positively associated with total estradiol (GM Q4 = 43.2 pg/mL (95% CI 36.5-51.1) vs. Q1 GM = 25.6 pg/mL (24.1-27.3), p-trend <0.0001) and free estradiol (GM Q4 = 0.77 pg/mL (95% CI 0.64-0.93) vs. Q1 GM = 0.47 pg/mL (0.44-0.51), p-trend = 0.002). Serum DDT concentration was positively associated with total estradiol (GM Q4 = 31.6 pg/mL (95% CI 25.9-38.5) vs. Q1 GM = 27.3 pg/mL (25.9-28.7), p-trend = 0.05) and free estradiol (GM Q4 = 0.60 pg/mL (95% CI 0.48-0.76) vs. Q1 GM = 0.50 pg/mL (0.47-0.53), p-trend 0.02). There was a suggestive inverse association of DDT and SHBG (GM Q4 = 29.2 nmol/L (95% CI 23.8-35.9) vs. Q1 GM = 33.9 nmol/L (32.3-35.5), p-trend 0.07). A positive association of β-hexachlorocyclohexane with total estradiol (GM Q4 = 30.3 pg/mL (95% CI 26.5-34.6) vs. Q1 GM = 26.7 pg/mL (24.5-29.0), p-trend = 0.09) was also suggestive but did not reach statistical significance. No distinct associations were observed for other hormone levels or other organochlorine pesticides.

CONCLUSIONS

Our findings suggest that select organochlorine pesticides may alter male estradiol levels. The positive associations with estradiol may implicate sex hormones as a possible mechanism for disease risk among those with organochlorine pesticide exposure.

Concentrations of organochlorine pesticides in placental tissue are not associated with risk for fetal orofacial clefts

Previous epidemiological studies have shown that prenatal exposure to organochlorine pesticides (OCPs) entails a variety of adverse impacts on fetal health, but it is not yet known whether it is associated with risk for orofacial clefts (OFCs). This study of 103 fetuses or newborns with a diagnosis of OFCs (cases) and 103 healthy newborns without malformations (controls) examined whether prenatal exposure to OCPs, as indicated by their concentrations in placental tissue, is a risk factor for OFCs. No differences were found in the median concentrations of OCPs between cases and controls, with exception of o,p'-dichlorodiphenyldichloroethylene, o,p'-dichlorodiphenyldichloroethane, and total o,p'-dichlorodiphenyltrichloroethane (DDTs), whose concentrations were higher in controls than in cases (Ps < 0.05). Although higher concentrations of placental δhexachlorocyclohexane and isodrin were found to be associated with decreased risk for OFCs in logistic regression, no association was observed in the Bayesian kernel machine regression, a novel statistical model in analyzing exposure mixtures. Women who reported periconceptional folic acid supplementation had lower placental concentrations of DDTs than women who did not. In conclusion, no association between levels of OCPs in placental tissue and risk for OFCs was observed in this population. Supplementation with folic acid may help decrease the levels of DDTs in placental tissue, but further studies are needed to confirm this unexpected finding.

Spatial distribution and compositional profiles of organochlorine pesticides in the surface soil from the agricultural, coastal and backwater transects along the south-west coast of India

South-west coast of India has a history of using pesticidal persistent organic pollutants (POPs) particularly endosulfan until aerial spraying was banned during early 2000. Since soil acts as a repository for such pesticidal persistent organic contaminants, we have monitored residues of seventeen organochlorine pesticides (OCPs) in the surface soil samples from the agricultural, coastal, and backwater transects along the south-west coast of India. OCPs concentration in soil were in the order agricultural > coastal > backwaters transects. Endrins, hexachlorocyclohexane (HCH) and heptachlors were among the dominant OCPs quantified in this study. Dominance of metabolites such as dichlorodiphenyldichloroethylene (DDE), dichlorodiphenyldichloroethane (DDD) and endosulfan sulfate indicates past usage. All the OCPs were dominant in the agricultural transect where plantations/agricultural activities are prevalent. In some specific sites, traces of HCH isomers showed ongoing usage of technical HCH in those sites contradicting the ban in agricultural sector. Backwater sites which are background locations showed positive correlation between soil organic carbon and soil borne OCPs thereby indicating an aged source possibly due to the short/long atmospheric transport from the site of application. Based on the policies regarding control, prevention and other measures for the management of pesticides in Kerala, it was concluded that the implementation on the ground level and the legal framework should be strengthened to prevent further illegal use of the banned pesticides.

Sources and health risks of PM2.5-bound polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) in a North China rural area

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are typical persistent organic pollutants (POPs), which have high toxicity, bioaccumulation and long-distance transfer capability. Daily variation, sources of PCBs and OCPs in PM_2.5 are rarely explored in polluted rural area. Here, the sources and health risks of the PCBs and OCPs were evaluated for 48 PM_2.5 samples collected in winter 2017 in Wangdu, a heavy polluted rural area in the North China Plain. The average diurnal and nocturnal concentrations of Σ₁₈PCBs and Σ₁₅OCPs were 1.74-24.37 and 1.77-100.49, 11.67-408.81 and 16.89-865.60 pg/m³, respectively. Hexa-CBs and penta-CBs accounted for higher proportions (29.0% and 33.6%) of clean and polluted samples, respectively. Hexachlorobenzene (HCB) was the dominant contributor to OCPs with an average concentration of 116.17 pg/m³. Hexachlorocyclohexane (ΣHCHs) and dichlorodiphenyltrichloroethane (ΣDDTs) were the other two main classes in OCPs with the average concentrations of 4.33 and 15.89 pg/m³, respectively. β-HCH and p,p'-DDE were the main degradation products of HCHs and DDTs, respectively. The principal component analysis and characteristic ratio method indicated both waste incineration and industrial activities were the main sources of PCBs, contributing 76.8% and 12.7%, respectively. The loadings of OCPs were attributed to their application characteristics and the characteristic ratio method reflected a current or past use of OCPs. Health risk assessment showed that the respiratory exposure quantity of doxin-like PCBs (DL-PCBs) and the lifetime cancer risk from airborne OCPs exposure was negligible, while the other exposure modes may pose a risk to human bodies.

Trophic transfer of pollutants within two intertidal rocky shore ecosystems in different biogeographic regions of South Africa

Tsitsikamma and Sheffield Beach are two relatively pristine sites along the South African east coast representing warm temperate and subtropical biogeographic rocky shore intertidal ecosystems, respectively. Stable isotopes (δ¹⁵N and δ¹³C), metals and organochlorine pesticides (OCPs) were measured in 38 intertidal components to study biomagnification or biodilution of metals and OCPs in these marine food webs. Comparison of the four species common to both sites revealed that the highest Al, Fe and OCP concentrations were measured in intertidal organisms from Sheffield Beach and was attributed to diffuse input into the nearshore marine environment sources via estuaries and groundwater. All other metals were higher in intertidal organisms from Tsitsikamma and were attributed to the metal-rich phytoplankton blooms during upwelling events. There was no correlation between metal and OCP accumulation and dietary source (δ¹³C) or trophic level (δ¹⁵N). The application of trophic magnification factors (TMFs) using a relatively short benthic food chain indicated biomagnification for As, Cd, Cu, Se and Zn and biodilution of OCPs at both sites. Since these food chains represent only a small portion of the intertidal ecosystems we found limited evidence of biomagnification or biodilution of metals and OCPs across species. This was attributed to different dietary sources in the same food web and similar trophic levels being occupied by the same species in different food chains. We found that food web composition rather than temperature-based biogeographical distribution influenced trophic transfer of metals and OCPs.

Residual effects of organochlorine pesticides (OCPs) in an e-waste recycling area compared with heavy metal pollution

Disposal of e-waste is a global issue and has caused serious pollution in recycling areas. Most of these areas had once developed intensive agriculture and might incur organochlorine pesticides (OCPs) pollution. However, this used to be neglected. Here we discuss the joint effects via analyzing OCPs and heavy metals in a notorious e-waste recycling area. The OCPs showed higher (p = 0.005) pollution levels in soils from agricultural zone than in core e-waste recycling zone, which is opposite for heavy metals (p = 0.02). The OCPs and heavy metals showed the highest concentrations in the open burning site locating in the boundary between the e-waste and agricultural zones. Composition profiles further indicated that the land use changes from agriculture to e-waste industry might accelerate the release of buried OCPs. Worse still, the OCPs and heavy metals might pose carcinogenic and non-carcinogenic risks to local residents, respectively.

Concentrations of persistent organic pollutants in maternal plasma and epigenome-wide placental DNA methylation

Background

Prenatal maternal plasma persistent organic pollutant (POP) concentrations have been associated with neonatal outcomes. However, the underlying mechanisms remain unknown. Placental epigenetic mechanisms may be involved, but no prior epigenome-wide studies have investigated the impact of maternal POPs on placental DNA methylation. We studied the association between maternal plasma POP concentration in early pregnancy and epigenome-wide placental DNA methylation among 260 pregnant women from the NICHD Fetal Growth Studies.

Results

Our analysis focused on POPs with more than 80% plasma concentrations above the limit of quantification, including 3 organochlorine pesticides (hexachlorobenzene, trans-nonachlor, p,p’-dichlorodiphenyldichloroethylene), 1 polybrominated diphenyl ether (PBDE 47), 3 polychlorinated biphenyls (138/158, 153, 180), and 6 poly- and perfluorinated alkyl substances (PFASs) (perfluorodecanoic acid, perfluorohexanesulfonic acid, perfluorononanoic acid, perfluorooctanesulfonic acid, perfluoroundecanoic acid (PFUnDA)). Using 5% false discovery rate, POPs were associated with a total of 214 differentially methylated CpG sites (nominal p values ranging from 2.61 × 10⁻²¹ to 2.11 × 10⁻⁷). Out of the 214 CpG sites, 24 (11%) were significantly correlated with placental expression of 21 genes. Notably, higher PFUnDA was associated with increased methylation at 3 CpG sites (cg13996963, cg12089439, cg18145877) annotated to TUSC3, and increased methylation at those 3 CpG sites was correlated with decreased expression of TUSC3 in the placenta. Increased methylation at cg18145877 (TUSC3) and decreased expression of TUSC3 were correlated with shorter birth length. Out of the 214 CpG sites, methylation at 44 CpG sites was correlated (p value < 0.10) with at least one neonatal anthropometry measure (i.e., birth weight, birth length, and head circumference). Seven CpG sites mediated (p value < 0.05) the association between PBDE 47 and neonatal anthropometry measures. Genes annotating the top differentially methylated CpG sites were enriched in pathways related to differentiation of embryonic cells (PBDE 47) and in pathways related to brain size and brain morphology (PFASs).

Conclusions

DNA methylation changes in the placenta were significantly associated with maternal plasma POPs concentration. The findings suggest that placental DNA methylation and gene expression mechanism may be involved in the prenatal toxicity of POPs and their association with neonatal anthropometry measures.

Validation of an Analytical Method for Simultaneous Determination of 18 Persistent Organic Pollutants in Trout Using LLE Extraction and GC-MS/MS

Persistent organic pollutants, (POPs), are vast distributed compounds in environment which are recognized as one of the global pollution problems. These groups of materials being dangerous due to their high stability are accumulated in animal tissues and occurring in the food chain. One of the major paths through which persistent organic combinations access to human body is consuming polluted foods, particularly, fishes. Among aquatic animals, trout as one of the mostly consumed fishes in Tehran’s food basket was studied. In this study, two categories of persistent organic pollutants: Organochlorine pesticides (OCPs) including HCB, Dieldrin, Methoxychlor, α-, ϒ-Chlordane, α-, β-Endosulfan and o,p’-DDE, p,p’-DDE, o,p’-DDT, p,p’-DDT and the second group Polychlonitated biphenyls (PCBs) including seven PCB congeners which are called indicator PCBs (IUPAC nos.: 28,52,101,118,138,153 and 180) were determined in trout by GC-MS/MS in MRM monitoring mode and LLE extraction. The average recoveries of OCPs and PCBs at five concentration levels (1, 2, 5, 10 and 20 ng/g for PCBs and 5 times for OCPs) were in the range of 73-112%. The relative standard deviations of POPs in fish were in the range of 1.4-17.9% for all of the concentration levels. The limit of detections (LODs) and the limit of quantitations (LOQs) were between 0.6-8.3 and 2-25 µg/kg, respectively. The results indicated the presence of organochlorine pesticides in trout and the levels of p,p’-DDE and p,p’-DDT were within the range of < LOQ -12.83 and < LOQ -10.2 ng/g ww (wet weight), respectively. According to the results, OCPs residues were lower than maximum residue levels set by European Council Directives.

Influence of polychlorinated biphenyls and organochlorine pesticides on the inflammatory milieu. A systematic review of in vitro, in vivo and epidemiological studies

BACKGROUND

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) are relevant families of persistent organic pollutants, which have been linked to several long-term adverse health effects. The mechanisms of action of these pollutants are still poorly understood. However, there are some evidences suggesting that inflammation might play a key role on their effects.

AIM

To systematically synthesize the published in vitro, in vivo and epidemiological data assessing the potential influence of exposure to OCPs and PCBs on the development of an inflammatory milieu.

METHODS

A systematic review of peer-reviewed original research papers published until 1st May 2019 was conducted, by using Medline, Web of Science and Scopus databases. A total of 39 articles met the inclusion criteria and were evaluated in this review.

RESULTS

The majority of the studies showed significant associations of PCB and OCP exposure with all inflammatory markers measured (n = 30). Some studies showed positive and negative associations (n = 7) and only two studies evidenced negative associations (n = 2). Most of the available evidences came from in vitro and in vivo studies (n = 31), with few epidemiological studies (n = 8).

CONCLUSIONS

We found consistent positive associations between exposure to PCBs and OCPs and the development of a pro-inflammatory milieu, with only few discrepancies. However, given the limited epidemiological evidence found, our results warrant further research in order to elucidate the real contribution of these pollutants on the inflammatory processes and subsequent diseases.

Historical residues of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in a flood sediment profile from the Longwang Cave in Yichang, China

Historical residual of persistent organic pollutants (POPs) in flood sediment from a karst cave were investigated. Fifteen vertical sediment samples were collected from a 6 m-deep flood sediment profile in the Longwang Cave, and the concentrations of organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) and particle size distribution in the sediments were analysed. The concentrations of OCPs and PAHs varied from 0.85 ng g^-1 to 63.1 ng g^-1 (mean 8.11 ng g^-1) and 5.05 ng g^-1 to 82.6 ng g^-1 (mean 13.9 ng g^-1), respectively; major PAHs in the profile were 2- and 3-ringed PAHs and a few were 5- or 6- ringed PAHs, which indicated less influence from industry but a high impact from the local combustion of coal and biomass; HCHs and DDTs in the profile were historically residual in this region, and HCHs mainly originated from the application of Lindane, while DDTs originated from the application of dicofol and technical DDTs; no significant correlation between the concentrations of OCPs and PAHs and the sedimental particle size in the sediments was found.

Pine needle and semi-permeable membrane device derived organochlorine compounds (OCPs) concentrations in air in Mersin Province to Taurus, Turkey

Organochlorine pesticides (OCPs) were analyzed in three different ages (half-, 1.5-, 2.5-year-old) for needles and semi permeable membrane devices (SPMDs) at three deployment periods from sea level to 1881 meter above sea level. Individual HCHs concentrations ranged between 1.4 and 129 pg/g fw depending on the age and sampling season while 2.5-year-old needles showed higher HCHs levels compared to half and 1.5- year-old. Correlation between elevation and HCH concentration in SPMDs was found but not in needle samples. Concentrations of HCHs in SPMDs indicated clearly cold condensation effect on accumulation in winter period and increased with altitude. Concentrations of DDTs in half and 1.5-year-old needles were lower than 2.5-year-old needles. The highest total concentration of DDTs was detected in 1-year-period SPMD. Higher concentrations were found in 2.5-year-old needles for other OCPs. Seasonal and altitude-dependent changes were not observed for other OCPs in SMPDs. Total accumulation of OCPs in SPMDs were found higher than in needles. On the contrary, an increased accumulation rate was observed for HCHs in SPMD. In general, Total concentrations of DDTs and HCHs were similar to total of other OCPs in all altitudes when dominating endosulfan wasnot taken into account in the computation of total concentration of other OCPs.

Health effects from contaminant exposure in Baltic Sea birds and marine mammals: A review

Here we review contaminant exposure and related health effects in six selected Baltic key species. Sentinel species included are common eider, white-tailed eagle, harbour porpoise, harbour seal, ringed seal and grey seal. The review represents the first attempt of summarizing available information and baseline data for these biomonitoring key species exposed to industrial hazardous substances focusing on anthropogenic persistent organic pollutants (POPs). There was only limited information available for white-tailed eagles and common eider while extensive information exist on POP exposure and health effects in the four marine mammal species. Here we report organ-tissue endpoints (pathologies) and multiple biomarkers used to evaluate health and exposure of key species to POPs, respectively, over the past several decades during which episodes of significant population declines have been reported. Our review shows that POP exposure affects the reproductive system and survival through immune suppression and endocrine disruption, which have led to population-level effects on seals and white-tailed eagles in the Baltic. It is notable that many legacy contaminants, which have been banned for decades, still appear to affect Baltic wildlife. With respect to common eiders, changes in food composition, quality and contaminant exposure seem to have population effects which need to be investigated further, especially during the incubation period where the birds fast. Since new industrial contaminants continuously leak into the environment, we recommend continued monitoring of them in sentinel species in the Baltic, identifying possible effects linked to climate change, and modelling of population level effects of contaminants and climate change.

Legacy persistent organic pollutants (POPs) in archive samples of wild Bluefin tuna from the Mediterranean Sea

Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were quantified in archive samples of dorsal white muscle of the wild Bluefin tuna (BFT) (n = 9) collected in the central Adriatic. PCBs were the predominant organochlorine (OC) compounds (60.8-69.4% of the total OC load) found. The contribution of HCB and ΣHCHs was significantly lower, ranging from <LOD (α- and β-HCH) to 1.5% (γ-HCH). p,p'-DDE was the predominant OCP compound (60-89% of the ΣOCPs). PCB and DDT levels were comparable to the values previously found for tuna from the Mediterranean Sea, known as one of the areas most polluted by PCBs.

Organochlorine pesticide residues in raw milk samples collected from dairy farms and urban areas of Lahore district, Pakistan

The current study was employed to investigate the organochlorine pesticides (OCP) concentrations in milk, as the milk we consume, has residues of these notorious pesticides. The residual concentrations of OCP in milk have numerous harmful effects on health especially the children. Therefore, milk was analyzed using gas chromatography equipped with µECD for seven OCP residues, namely α-endosulfan, β-endosulfan, Endosulfan-sulphate, DDE, γ-HCH, Dieldrin, and DDT. Three hundred and sixty raw milk samples were collected from urban areas (10 areas of Lahore N = 300) and Dairy Farms (10 farms in Lahore N = 60) from September 2012 to September 2013. Samples were collected after an interval of 2 months, for 12 months. Mean values of OCPs in milk samples from urban areas were reported as α-endosulfan, β-endosulfan, Endosulfan-sulphate, DDE, γ-HCH, and Dieldrin with concentration of 17.44 ± 3.99, 35.74 ± 7.50, 20.28 ± 3.95, 2.51 ± 0.55, 0.93 ± 0.16 and 1.12 ± 0.18 µg kg^-1, respectively, while the milk samples from dairy farms with concentration of 26.94 ± 4.63, 59.88 ± 6.76, 32.07 ± 4.51, 4.64 ± 0.48, 1.20 ± 0.17 and 1.93 ± 0.18 µg kg^-1, respectively. None of the samples analyzed were found positive for the presence of DDT, just as none of the samples from area milk shops exceeded the Maximum Residual Limits (MRLs). γ-HCH and β-endosulfan were found higher in dairy farm milk samples than the MRLs. Conclusively, these pesticide residues are present in milk available in Lahore in enough quantity (some exceeding the MRLs) to threaten human health, particularly the infant and children.

Exposure assessment of toxic metals and organochlorine pesticides among employees of a natural history museum

Chemical compounds such as arsenic, mercury and organochlorine pesticides have been extensively used as preventive and curative conservation treatments for cultural and biological collections to protect them from pest and mold infestations. Most of the aforementioned compounds have been classified as carcinogenic, mutagenic and teratogenic and represent a health risk for members of staff exposed to contaminated objects. The present study addresses the internal exposure of 28 museum employees in Museum für Naturkunde Berlin by measuring arsenic species and mercury in urine as well as hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH), hexachlorobenzene (HCB), dichlorodiphenyltrichloroethane (4,4'-DDT) and its main metabolite, dichlorodiphenyldichloroethylene (4,4'-DDE), and pentachlorophenol (PCP) in blood serum. This study was carried out in order to assess the internal exposure of Natural History Museum staff members to toxic metals and organochlorine pesticides. During a working week, two blood samples and five urine samples were taken from each participant, involving 8 women and 20 men. Information about work activity and exposure related factors such as dust development through work, use of personal protective equipment, as well as a nutrition diary were obtained through a questionnaire. Information on fish and seafood intakes as well as amalgam fillings was also available. The results of the study showed that the museum staff members had quantified concentrations of arsenic (median of 6.4 μg/l; maximum of 339 μg/l), mercury (median of 0.20 μg/l; max of 2.6 μg/l), β-HCH (median of 0.12 μg/l; max of 0.39 μg/l) and 4,4'-DDT (median of 0.050 μg/l; max of 0.82 μg/l). Despite that all the concentrations were below the established reference values, multivariate regression models were able to show that museum staff members are currently exposed to the aforementioned compounds while handling museum objects. To validate our findings, further studies are required.

Organochlorine pesticides induce inflammation, ROS production, and DNA damage in human epithelial ovary cells: An in vitro study

Although the etiology of ovarian cancer is not clear, certain factors are implicated in this disease, such as ovulation, gonadotropic and steroid hormones, growth factors, cytokines, environmental agents, etc. Epidemiological studies have proven environmental exposure to pesticides with an increased risk of Epithelial Ovarian Cancer (EOC); however, the molecular mechanism underlying the carcinogenic effects of pesticides in human ovary remains poorly understood. The present study aimed to study the pro-inflammatory response of organochlorine pesticides (OCPs) namely β-hexachlorocyclohexane (β-HCH), dichlorodiphenyldichloroethylene (DDE) and Dieldrin following exposure to human ovary surface epithelial cells (HOSE) for risk prediction of epithelial ovarian cancer. We found high level of Reactive oxygen species (ROS) production and DNA damage along with up-regulation of pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, nuclear factor kappa B (NF-kB) and cyclooxygenase (COX)-2 expression in OCPs treated HOSE cells compared to control (DMSO). The result of the present study suggests that β-HCH, DDE, and Dieldrin exposure induce ROS and pro-inflammatory response as well as DNA damage in HOSE cells. These various results show that OCPs may account for the neoplastic transformation of HOSE cells in the ovary.

Organochlorine Pesticides and Potentially Toxic Elements in Groundwater from a Protected Reserve in the Maya Region of Hopelchen, Mexico

Water quality degradation by organochlorine pesticides and potentially toxic elements is of worldwide concern. This research explores groundwater conditions, regarding organochlorine pesticides and potentially toxic elements, in Hopelchen, Campeche, which is located in the buffer zone of the Calakmul Biosphere Reserve. Unfortunately, agriculture is allowed and agrochemical use is not monitored and sanctioned. Results show that Heptachlor, Endosulfan, and Dieldrin, all recognized carcinogens, had concentrations above the Mexican normative recommended values. Conversely, Cd and Ni concentrations were below recommended values. These results demonstrate that government intervention involving immediate control over agrochemical use is mandatory. Also, the results underscore the contamination of groundwater in several of the Calakmul Biosphere Reserve's buffer zones by organochlorine pesticides concentrations, posing a probable threat for local inhabitants who consume this water and use it for recreation.

Mercury and Organochlorine Pesticides in Tissues of Loggerhead Sea Turtles (Caretta caretta) Stranded Along the Southwestern Mediterranean Coastline (Andalusia, Spain)

Nineteen loggerhead sea turtles (Caretta caretta) stranded along the southwestern Mediterranean coastline (Andalusia) were used in this study. A total of 68 samples of fat (n = 18), liver (n = 15), kidney (n = 13), pectoral muscle (n = 19), and brain (n = 3) were analysed for total mercury (Hg) and organochlorine pesticides [OC: ∑Dichlorodiphenyltrichloroethanes (∑DDT), ∑Hexachlorocyclohexane (∑HCH), ∑Heptachlor, ∑Drins and ∑Endosulfan]. These loggerhead sea turtles showed tissue Hg and OC concentrations similar to or lower than those reported in other studies. Few growth-related variations in Hg or OC levels in relation to straight carapace length were found, probably because the specimens were mostly juveniles. This study will help to fill the gap on spatio-temporal exposure data and ascertain the real world-wide picture of the contamination levels in loggerhead sea turtles.

Organic pollutants in sedimentary microplastics from eastern Guangdong: Spatial distribution and source identification

Microplastics have a strong affinity for potentially toxic organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs). Since 2005, the International Pellet Watch used plastic pellets to monitor hydrophobic organic contaminants in marine environments. We examined the spatial distribution and sources of 16 PAHs and eight OCPs on microplastics (pellets, fragments, and foam) collected from eastern Guangdong beaches with the goal of evaluating the feasibility of exclusively using pellets in global monitoring of hydrophobic organic contaminants. The ∑PAH and ∑OCP concentrations ranged from 11.2 to 7710 ng g^-1 and 2.2-1970 ng g^-1, respectively. Although inter-site and regional differences were insignificant in fragments and foam, regional differences were observed in ∑OCP concentrations on pellets samples collected at the estuary mouth and the distributary (p < 0.05). No regional difference in ∑PAH concentration on microplastics was observed, except between fragments from the remote beach and those from the distributary (p = 0.015) and the estuary mouth (p = 0.015). The compositional profiles of PAHs revealed that PAHs with 2-4 rings were more dominant than those with >4 rings. Considering low molecular weight PAHs are less hydrophobic and more toxic; the results suggest low molecular weight PAHs may pose a significant risk to marine organisms. This study shows that the International Pellet Watch could offer critical data on source and transport of microplastic-associated OCPs but may overlook critical vehicles of PAHs in coastal environments such as foam.

Assessment of persistent organic pollutants in hair samples collected from several Iranian wild cat species

Persistent organic pollutants (POPs), including the organochlorine pesticides (OCPs), such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), α, β and γ-hexachlorocyclohexane (HCH) isomers, and the polychlorinated biphenyl (PCB) congeners (IUPAC Nos. 28, 52, 101, 138, 153, and 180), were determined in hair samples collected from 41 Iranian wild cats belonging to 8 different species. This is the first report on the presence of selected POPs in feline hair from museum collections and it is an indication of the concentrations of OCPs and PCBs in Iran from 2000 to 2010. Median concentrations of HCHs, DDTs, PCBs, and HCB were 108, 99, 70 and 38 ng/g hair, respectively. p,p'-DDE and β-HCH were the most abundant OCPs (detected in 91% and 74%, respectively, of the analyzed samples), while CB 180 and CB 138 were the predominant PCB congeners, found respectively in 49% and 61% of the samples. Significant differences (p < 0.05) in the median concentrations of DDTs were found among species grouped according to both their feeding habits and territory range. Levels of DDTs and PCBs were generally higher in the omnivorous species compared with the carnivorous ones, likely due to both their dietary habits and habitat in the proximity of human settlements.

Electrochemically assisted dewatering for the removal of oxyfluorfen from a coagulation/flocculation sludge

This work focuses on the evaluation of the electrochemical dewatering of sludge obtained in the coagulation of wastes polluted with oxyfluorfen. To do this, sludge samples were treated, aiming not only to reduce the sludge volume, but also to facilitate the degradation of oxyfluorfen contained in the cake via electrolysis with a boron-doped diamond anode. Results show that water can be effectively recovered through three sequential stages. First, a gravity-driven stage, that can recover around 60% of initial volume and where no oxyfluorfen is dragged. Then, a second stage that involves the application of pressure and which accounts for the recuperation of an additional 25% of the total volume of the water removed and in which oxyfluorfen also remained in the cake. Finally, an electrochemical stage, which involves the application of electricity with increasing electric fields (1.0, 2.0, 4.0, and 16.0 V cm^-1), accounting for the recovery of the rest of water released and where an electrolytic degradation of oxyfluorfen is obtained, whose extension depends on the electrode configuration used in the electro-dewatering cell. This electrode configuration also influences the retention or loss of oxyfluorfen from the cake, being the optimum choice the placement of the cathode downstream, next to the outlet of the dewatering cell.

Exposure to organochlorine pesticides and the risk of type 2 diabetes in the population of East China

Organochlorine pesticides (OCPs) have been reported to be associated with an elevated risk of type 2 diabetes, although no study has focused on such associations in Chinese populations. In this case-control study, we aimed to explore the associations between OCPs and type 2 diabetes and their potential mechanisms in a population from East China. Participants diagnosed with type 2 diabetes and nondiabetic participants from Shandong Province, East China, were enrolled in this case-control study. Six OCPs (β-HCH, trans-chlordane, trans-nonachlor, p,p'-DDE, p,p'-DDT and mirex/kepone) were detected in more than 75% of serum samples. Logistic regression analysis and multiple linear regression analysis were used to assess the associations between OCP exposure and the outcomes. After adjusting for potential confounding factors such as age, sex and body mass index, all six OCPs showed positive associations with type 2 diabetes in a linear dose-response manner. Serum concentrations of β-HCH and p,p'-DDE were associated with higher levels of fasting plasma glucose in participants without diabetes, although no OCPs showed significant associations with hemoglobin A1c. In addition, certain OCPs showed significantly positive associations with triglycerides, total cholesterol, and low-density lipoprotein cholesterol and negative relationships with high-density lipoprotein cholesterol in nondiabetics, indicating that OCP exposure may disrupt lipid metabolism. Findings in the current study indicated that OCPs may be a diabetogenic factor in the population of this study. To our knowledge, this is the first study to investigate the associations between OCP exposure and type 2 diabetes in a Chinese population.

Organochlorine pesticides residue in placenta and their influence on anthropometric measures of infants

The objective of this study is to evaluate the influence of placental concentrations of some organochlorine pesticides on newborn's anthropometric measurements (height, weight, head circumference & ponderal index). For this study, we have collected 90 placental tissue samples for the measurement of Dichlorodiphenyltrichloroethane (DDT) & Hexachlocyclohexane (HCH) by Gas Chromatography equipped with Electron Capture Detector (GC-ECD). Regression analysis were performed between outcome variables such as birth weight, birth height, head circumference, ponderal index and independent variable i.e., organochlorine pesticide concentrations. In case of birth weight, there was a substantial decrease of 5.81, 1.94, 4.71, and 2.64 g for 1 ppb (μg/L) increase in placental α-HCH, β-HCH, γ-HCH, and total HCH concentrations respectively. Significant decrease of 2.02 and 0.43 kg/m³ in ponderal index was found with 1 μg/L increase of total-HCH and total DDT concentrations in placenta. The results of this study support an association between environmental exposure to organochlorine pesticides and anthropometric development of the fetus leading to a significant reduction in its birth weight and ponderal index, slight and non-significant reduction in birth height and head circumference. Efforts should be made to reduce exposure of women of reproductive age in relation to long-term impact on health.

Spatial distribution and sources of pesticidal persistent organic pollutants in the Hooghly riverine sediment

Given the extensive indiscriminate usage in the past and limited ongoing use, organochlorine pesticides (OCPs) have been widely reported in the Hooghly riverine environment. Hence, surface riverine sediment samples were collected along the urban and suburban transects of the Hooghly River and OCPs were quantified in gas chromatography mass spectrometry (GC-MS). Mean concentration of HCH, DDT, and endosulfan was 5 ng g^-1, 10 ng g^-1, and 4 ng g^-1 respectively. DDT was dominant among all the OCPs and contributed nearly 40% to the total OCPs possibly due to the ongoing use of DDT for vector control programs. Diagnostic ratios suggest recent source of lindane, DDT, and endosulfan. Using OCP concentration from previously published data in surface water during the same time frame, sediment-water partitioning of OCPs was estimated. Excluding α-HCH and γ-HCH in few pockets, majority of the OCPs tend to partition more on to sediment. Comparing the sediment concentration with the sediment quality guideline values, risk on ecological integrities was indicated due to DDT and HCH contamination. Suburban sites indicated higher risk than urban sites according to the calculated sediment quality guideline quotient (SQGQ). A brief review on the approach to pesticidal POP pollution management in India revealed that older management approaches should be replaced with a unique, integrated, and holistic system.