Distribution of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in human serum from urban areas in Korea

Microbiota dysbiosis associated with type 2 diabetes-like effects caused by chronic exposure to a mixture of chlorinated persistent organic pollutants in zebrafish

Mixtures of chlorinated persistent organic pollutants (C-POPs-Mix) are chemically related risk factors for type 2 diabetes mellitus (T2DM); however, the effects of chronic exposure to C-POPs-Mix on microbial dysbiosis remain poorly understood. Herein, male and female zebrafish were exposed to C-POPs-Mix at a 1:1 ratio of five organochlorine pesticides and Aroclor 1254 at concentrations of 0.02, 0.1, and 0.5 μg/L for 12 weeks. We measured T2DM indicators in blood and profiled microbial abundance and richness in the gut as well as transcriptomic and metabolomic alterations in the liver. Exposure to C-POPs-Mix significantly increased blood glucose levels while decreasing the abundance and alpha diversity of microbial communities only in females at concentrations of 0.02 and 0.1 μg/L. The majorly identified microbial contributors to microbial dysbiosis were Bosea minatitlanensis, Rhizobium tibeticum, Bifidobacterium catenulatum, Bifidobacterium adolescentis, and Collinsella aerofaciens. PICRUSt results suggested that altered pathways were associated with glucose and lipid production and inflammation, which are linked to changes in the transcriptome and metabolome of the zebrafish liver. Metagenomics outcomes revealed close relationships between intestinal and liver disruptions to T2DM-related molecular pathways. Thus, microbial dysbiosis in T2DM-triggered zebrafish occurred as a result of chronic exposure to C-POPs-Mix, indicating strong host-microbiome interactions.

Exposure of the general French population to herbicides, pyrethroids, organophosphates, organochlorines, and carbamate pesticides in 2014-2016: Results from the Esteban study

Esteban is a nationwide cross-sectional study conducted in France in 2014-2016, including 2503 adults aged 18-74 years old and 1104 children aged 6-17 years old, as part of the French Human Biomonitoring programme. The present paper describes the biological levels of five families of pesticides analysed on random sub-samples of 900 adults and 500 children for urine concentrations, and 759 adults and 255 children for serum concentrations, and the determinants of exposure. Organophosphates, carbamates and herbicides were measured in urine by UPLC-MS/MS; chlorophenols and pyrethroids were measured in urine by GC-MS/MS; specific organochlorines were measured in serum by GC-HRMS. Multivariate analyses were performed to identify the determinants of exposure using a generalized linear model. Pyrethroid metabolites were quantified in 99% of adults and children, with the exeption of F-PBA, which was quantified in 31% of adults and 27% of children, respectively. Carbamates and some specific organophosphates were barely or not quantified. DMTP was quantified in 82% of adults and 93% of children, and γ-HCH (lindane) was quantified in almost 50% of adults and children. Concentration levels of pesticide biomarkers were consistent with comparable international studies, except for β-HCH, DMTP, and the deltamethrin metabolite Br2CA, whose levels were sometimes higher in France. Household insecticide use and smoking were also associated with higher levels of pyrethroids. All pyrethroids concentration levels were below existing health-based HBM guidance values, HBM-GVsGenPop, except for 3-PBA, for which approximately 1% and 10% of children were above the lower and upper urine threshold values of 22 μg/L and 6.4 μg/L, respectively. Esteban provides a French nationwide description of 70 pesticide biomarkers for the first time in children. It also describes some pesticide biomarkers for the first time in adults, including glyphosate and AMPA. For the latter, urine concentration levels were overall higher in children than in adults. Our results highlight a possible beneficial impact of existing regulations on adult exposure to organochlorine and organophosphate pesticides between 2006 and 2016, as concentration levels decreased over this period.

Nationwide assessment of atmospheric organochlorine pesticides over a decade during 2008-2017 in South Korea

Long-term nationwide atmospheric monitoring of organochlorine pesticides (OCPs) was performed in South Korea during 2008-2017. Their occurrences, seasonal and temporal variability, sources, and effect of ambient temperature were investigated. The OCPs are pronounced with a mean concentration of total OCPs ranging from 5.2 to 256 pg/Sm³. However, a decrease of 54 % was observed in the mean concentration of total OCPs from 2008 to 2017 associated with regulatory actions. OCP concentrations did not show any variations between the different site types, and OCPs were ubiquitously present at all site types. The mean concentration of total OCPs in summer was two-fold higher than in winter. The concentrations of DRINs, DDTs, ENDOs, and HCHs were significantly higher in summer, but the concentrations of chlordane and heptachlor were higher in winter. The diagnostic ratios identified major sources as ongoing sources, past use, and atmospheric transport. Clausius Clapeyron plots strongly suggested the re-emission of α-endosulfan, β-endosulfan, α-HCH, and β-HCH, and ΔH_sa (enthalpy of surface air exchange) values suggested the influence of the transport and/or new sources on aldrin, dieldrin, and chlordane. The occurrence of OCPs due to re-emissions, ongoing sources, and long-range atmospheric transport could be a challenge towards the complete phase-out of OCPs in South Korea.

Organochlorine pesticides in the urban, suburban, agricultural, and industrial soil in South Korea after three decades of ban: Spatial distribution, sources, time trend, and implicated risks

Organochlorine pesticides in soil samples across urban, suburban, agricultural, and industrial sites were analyzed every year between 2013 and 2016 in South Korea. The study aims to understand the residual status, diminution of occurrence from the South Korean environment, and its risk to humans after three decades of the ban. A general decreasing trend of OCPs has been observed over the years. The OCP concentrations were below the guideline values prescribed for soil pollution. Metabolites like p,p'-DDD and endosulfan sulfate contributed a major portion to the total OCP concentration over the years. The agricultural sites showed higher OCP levels than other site types. Compositional profile and diagnostic ratios suggested that the occurrence of DDT and endosulfan residues were due to historical inputs, but those of HCH and chlordane reflect recent usage in some pockets. The calculated incremental lifetime cancer risk was within the safety limit for all age groups across the genders in the majority of the sites. It is evident that the OCP load on soil is decreasing since the ban on usage. However, regular monitoring with a special focus on metabolites can be an effective control measure to regulate and eliminate the contamination of OCPs.

Health risk assessment of exposure to organochlorine pesticides in the general population in Seoul, Korea over 12 years: A cross-sectional epidemiological study

This study evaluated the 12-year trends in serum levels of 28 organochlorine pesticides (OCPs) in 880 adults living in Seoul, Korea. The OCP levels decreased from 2006 to 2017, and p,p'-dichlorodiphenyldichloroethylene was a predominant compound. OCP levels were higher in females than in males, and showed positive associations with BMI and age. The OCP concentrations had inverted U-shaped associations with low-density lipoprotein cholesterol and total cholesterol. Concentrations of β-hexachlorocyclohexane were significantly higher in patients with hypertension than in participants that were normotensive. OCP levels showed positive associations with uric acid, creatinine, and thyroid-stimulating hormone, but negative associations with free thyroxine. Participants with diabetes had significantly higher OCP levels than those without it. Principal component analysis suggested possible differences in disease manifestation depending on the composition of OCPs. These results suggest that OCPs might disturb renal transport and thyroid homeostasis. To our knowledge, the inverted U-shaped associations of heptachlor epoxide and endosulfan with cholesterol, the epidemiological associations of trans-nonachlor and endosulfan with thyroid hormones, and the association of p,p'-DDE with hyperuricemia have not been previously reported in general population. This is the first long-term study to show trends of 28 OCPs in serum and associations with various health indicators in Korea.

Biomonitoring of 89 POPs in blood serum samples of Czech city policemen

In this biomonitoring study, we evaluated the concentrations of 8 polychlorinated biphenyls (PCBs), 11 organochlorinated pesticides (OCPs), 33 brominated flame retardants (BFRs), 7 novel brominated and chlorinated flame retardants (novel FRs) and 30 per- and polyfluoroalkylated substances (PFAS) in human serum samples (n = 274). A total of 89 persistent organic pollutants (POPs) were measured in blood serum samples of city policemen living in three large cities and their adjacent areas (Ostrava, Prague, and Ceske Budejovice) in the Czech Republic. All samples were collected during the year 2019 in two sampling periods (spring and autumn). The identification/quantification of PCBs, OCPs, BFRs, novel FRs and PFAS was performed by means of gas chromatography coupled to (tandem) mass spectrometry (GC-MS/(MS)) and ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-MS/MS). The most frequently detected pollutants were perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluorooctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), 2,2',3,4,4',5'-hexachlorobiphenyl (CB 138), 2,2',4,4',5,5'-hexachlorobiphenyl (CB 153), 2,2',3,3',4,4',5-heptachlorobiphenyl (CB 170), 2,2',3,4,4',5,5'-heptachlorobiphenyl (CB 180), hexachlorobenzene (HCB), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) quantified in 100% of serum samples. In the serum samples, the concentrations of determined POPs were in the range of 0.108-900 ng g^-1 lipid weight (lw) for PCBs, 0.106-1016 ng g^-1 lw for OCPs, <0.1-618 ng g^-1 lw for FRs and <0.01-18.3 ng mL^-1 for PFAS, respectively. Locality, sampling season, and age were significantly associated with several POP concentrations. One of the important conclusions was that within the spring sampling period, statistically significant higher concentrations of CB 170 and CB 180 were observed in the samples from Ostrava (industrial area) compared to Prague and Ceske Budejovice. Older policemen had higher concentrations of five PCBs and two OCPs in blood serum.

Feces are Effective Biological Samples for Measuring Pesticides and Flame Retardants in Primates

The habitats of wild primates are increasingly threatened by surrounding anthropogenic pressures, but little is known about primate exposure to frequently used chemicals. We applied a novel method to simultaneously measure 21 legacy pesticides (OCPs), 29 current use pesticides (CUPs), 47 halogenated flame retardants (HFRs), and 19 organophosphate flame retardants in feces from baboons in the U.S.A., howler monkeys in Costa Rica, and baboons, chimpanzees, red-tailed monkeys, and red colobus in Uganda. The most abundant chemicals were α-hexachlorocyclohexane (α-HCH), β-hexachlorocyclohexane (β-HCH), and hexachlorobenzene among OCPs across all sites, chlorpyrifos among CUPs in Costa Rica and Indiana, decabromodiphenylethane (DBDPE) in Costa Rica and Indiana and 2, 2', 4, 4'-tetrabromodiphenyl ether (BDE-47) in Uganda as HFRs, and tris(2-butoxyethyl) phosphate (TBOEP) as OPFRs across all sites. The detected chemical concentrations were generally higher in red-tailed monkeys and red colobus than in chimpanzees and baboons. Our methods can be used to examine the threat of chemical pollutants to wildlife, which is critical for endangered species where only noninvasive methods can be used.

2,3',4,4',5-Pentachlorobiphenyl Induced Thyrocyte Autophagy by Promoting Calcium Influx via Store-Operated Ca2+ Entry

PCB118, a 2,3',4,4',5-pentachlorobiphenyl, has been shown to destroy thyroidal ultrastructure and induce thyrocyte autophagy. Previously, we reported that PCB118 promoted autophagosome formation in vivo and in vitro, but more details remain to be revealed. To explore the underlying mechanism by which PCB118 regulates thyrocyte autophagy, Fischer rat thyroid cell line-5 (FRTL-5) cells were exposed to different doses of PCB118 at 0, 0.25, 2.5, and 25 nM for 0-48 h. Western blot analysis of autophagy-related proteins P62, BECLIN1, and LC3 demonstrated that PCB118 induced autophagy formation in dose- and time-dependent manner. Moreover, laser scanning confocal microscopy and flow cytometry showed PCB118 treatment led to time- and dose-dependent increase in intracellular calcium concentration ([Ca2+]i). Additionally, PCB118 promoted store-operated Ca2+ entry (SOCE) channel followed by significant increase of ORAI1 and STIM1 protein levels. On the other hand, PCB118 induced thyroidal autophagy via class III β-tubulin (TUBB3)/death-associated protein kinase 2 (DAPK2)/myosin regulatory light chain (MRLC)/autophagy-related 9A (ATG9A) pathway in FRTL-5 cells. Pretreatment with SOCE inhibitor SKF96365 reduced cytosolic Ca2+, ORAI1, STIM1, and BECLIN1 levels as well as LC3 II/LC3 I ratio, while increased P62 expression. SKF96365 also inhibited TUBB3/DAPK2/MRLC/ATG9A pathway in FRTL-5 cells treated by PCB118. Our results provide evidence that PCB118 may induce thyroidal autophagy through TUBB3-related signaling pathway, and these effects are likely to be regulated by calcium influx via SOCE channel.

Is dietary macronutrient intake associated with serum concentrations of organochlorine pesticides in humans?

In the general population, chronic exposure to low-dose persistent organic pollutants (POPs), particularly organochlorine pesticides (OCPs), has been recently linked to many chronic diseases. Widespread contamination of the food chain and human adipose tissue has made avoiding exposure to these chemicals impossible; thus, alternative strategies for decreasing the chemical burden must be investigated. Recently, macronutrient intake was found to significantly modify the toxicokinetics of POPs in animal experimental studies. Thus, we evaluated whether macronutrient intake was related to serum concentrations of OCPs in healthy adults without cardio-metabolic diseases. Subjects included 1,764 adults, aged 20 years or above, who participated in the National Health and Nutrition Examination Survey 1999-2004. Macronutrient intake was assessed based on a 24-h dietary recall interview. Six individual OCPs commonly detected among the general population were evaluated as markers of OCPs and other coexisting lipophilic chemicals stored in adipose tissue and released into circulation. High fat intake was associated with lower concentrations of OCPs, while high carbohydrate intake showed the opposite result. When three types of fats were individually evaluated, both saturated fatty acids and monounsaturated fatty acids, but not polyunsaturated fatty acids, were inversely associated with serum concentrations of OCPs. Adjustment for possible confounders did not change the results. When stratified by age, gender, body mass index, and physical activity, these associations were similar in most subgroups. Thus, similar to the findings observed in animal experimental studies, a moderate-fat diet with low carbohydrate intake was related to low serum concentrations of OCPs in humans. Although these findings need to be replicated, changing dietary macronutrient intake can be investigated as a practical strategy for dealing with unavoidable lipophilic chemical mixtures such as OCPs in modern society.

Occurrence and risk evaluation of organochlorine contaminants in surface water along the course of Swartkops and Sundays River Estuaries, Eastern Cape Province, South Africa

Organochlorine contaminants were analysed in surface water from Sundays (SDE) and Swartkops Estuaries (SWE), Eastern Cape Province, which is among the largest estuaries in South Africa. The concentration of Σ₁₈OCPs ranged from 16.7 to 249.2 ng/L in autumn, 19.9-81.4 ng/L in winter, 43.6-126.8 ng/L in spring and 68.3-199.9 ng/L in summer for SDE, whereas in SWE, the values varied from 20.9 to 259.7 ng/L in autumn, 58.9-263.9 ng/L in winter, 3.2-183.6 ng/L in spring and 118.0-188.9 ng/L in summer. Among all OCPs, α-HCH, β-HCH, p,p'-DDE, p,p'-DDT, endrin, dieldrin and endrin aldehyde were predominant in surface water samples from SDE and SWE. Furthermore, the mean concentration of polychlorinated biphenyls (PCBs) ranged from 126.7 ng/L in winter to 151.0 ng/L in spring for SDE and 249.0 ng/L in spring to 727.6 ng/L in winter for SWE. Tri- and tetra-PCBs dominated the PCB homologue profile. Hierarchical cluster analysis grouped the study sites into three regions from least polluted to most polluted, indicated that SWE is more polluted compared to SDE, probably due to the influx of agricultural and industrial effluents. Carcinogenic and non-carcinogenic risk assessment revealed that the water from both estuaries is not safe for drinking, although suitable for bathing.

Application of ensemble methods to analyse the decline of organochlorine pesticides in relation to the interactions between age, gender and time

Organochlorine pesticides (OCPs) are toxic chemicals that persist in human tissue. Short and long term exposure to OCPs have been shown to have adverse effects on human health. This motivates studies into the concentrations of pesticides in humans. However these studies typically emphasise the analysis of the main effects of age group, gender and time of sample collection. The interactions between main effects can distinguish variation in OCP concentration such as the difference in concentrations between genders of the same age group as well as age groups over time. These are less studied but may be equally or more important in understanding effects of OCPs in a population. The aim of this study was to identify interactions relevant to understanding OCP concentrations and utilise them appropriately in models. We propose a two stage analysis comprising of boosted regression trees (BRTs) and hierarchical modelling to study OCP concentrations. BRTs are used to discover influential interactions between age group, gender and time of sampling. Hierarchical models are then employed to test and infer the effect of the interactions on OCP concentrations. Results of our analysis show that the best fitting model of an interaction effect varied between OCPs. The interaction between age group and gender was most influential for hexachlorobenzene (HCB) concentrations. There was strong evidence of an interaction effect between age group and time for β-hexachlorocyclohexane (β-HCH) concentrations in >60 year olds as well as an interaction effect between age group and gender for HCB concentrations for adults aged >45 years. This study highlights the need to consider appropriate interaction effects in the analysis of OCP concentrations and provides further insight into the interplay of main effects on OCP concentration trends.

Integration of five groups of POPs into one multi-analyte method for human blood serum analysis: An innovative approach within biomonitoring studies

Within this study, a new analytical strategy was developed and validated for the simultaneous determination of 78 organohalogenated contaminants in human blood serum, namely 40 flame retardants (FRs) including 7 "novel" brominated and chlorinated FRs (novel FRs), 19 perfluoroalkylated substances (PFASs), 11 organochlorine pesticides (OCPs) and 8 polychlorinated biphenyls (PCBs). The integral sample preparation procedure was implemented for the isolation of non-polar compounds, based on three-step solvent extraction using a mixture of n-hexane:diethylether (9:1, v/v), followed by purification using a solid-phase extraction (SPE) on a Florisil® column. For isolation of more polar and lipophobic analytes, the remaining fraction from the first extraction step was further processed, using a modified QuEChERS method. Depending on the polarity and volatility of target compounds, either gas chromatography coupled to (tandem) mass spectrometry (GC-MS/(MS)), or ultra-high performance liquid chromatography coupled to triple quadrupole tandem mass spectrometry (UHPLC-MS/MS), was employed for their identification/quantification. Within the subsequent pilot study, the new validated procedure was successfully applied to the monitoring of organohalogenated contaminants in 38 samples of human blood serum obtained from Prague, Czech Republic. From 78 targeted analytes, 10 PFASs, 10 OCPs, 8 PCBs and 6 BFRs were detected in serum at concentrations above method quantification limits (MQLs). In the serum samples, the amounts of determined PFASs were in the range<0.01-8.97ngmL^-1 (mean 0.631ngmL^-1), OCPs and PCBs ranged from <0.1-1626ngg^-1 lw (mean 40.0ngg^-1 lw) and<0.1-481ngg^-1 lw (mean 63.3ngg^-1 lw), respectively.

2,3',4,4',5-Pentachlorobiphenyl induced autophagy of the thyrocytes via DAPK2/PKD/VPS34 pathway

2,3',4,4',5-Pentachlorobiphenyl (PCB118) has been shown to cause thyroidal ultrastructure lesions, but the underlying mechanism remains elusive. This study aimed to elucidate the mechanism by which PCB118 induces the abnormalities of the thyrocytes. Wistar rats were injected intraperitoneally with PCB118 (0, 10, 100 and 1000 μg/kg/d) for 13 weeks, and FRTL-5 cells were treated with PCB118 (0, 0.25, 2.5 and 25 nM). Transmission electron microscopy showed typical autophagosomes in the thyroid of PCB118-treated rats. Immunofluorescence staining showed dose-dependent increase of autophagy in FRTL-5 cells exposed to PCB118. In vivo and vitro studies found that Tubulin beta 3 class III (Tubb3) mRNA and protein levels decreased significantly, while Death-associated protein kinase 2 (DAPK2) increased after PCB118 exposure, and the binding between Tubb3 and DAPK2 was enhanced by PCB118 in a dose-dependent manner. Moreover, PCB118 resulted in the upregulation of Protein kinase D (PKD) and downregulation of Phosphatidylinositol 3-kinase (VPS34) in mRNA levels, and the activation of PKD and VPS34 phosphorylation. Additionally, Tubb3 small interfering RNA (siTubb3) suppressed DAPK2 protein expression and PKD phosphorylation in FRTL-5 cells, while VPS34 phosphorylation was inhibited by siPKD. Furthermore, DAPK2, PKD and VPS34 were upregulated by Tubb3 overexpression following PCB118 exposure. Our results demonstrate that low concentrations of PCB118 could promote thyroid autophagy formation and cause the abnormalities in thyroidal ultrastructure, and these effects are likely to be mediated by DAPK2/PKD/VPS34 dependent pathway.

Prenatal exposure to persistent organic pollutants and methylation of LINE-1 and imprinted genes in placenta: A CHECK cohort study

Prenatal exposure to persistent organic pollutants (POPs) has been linked to numerous adverse birth outcomes among newborn infants in many epidemiological studies. Although epigenetic modifications have been suggested as possible explanations for those associations, studies have rarely reported a relationship between POP exposure during pregnancy and DNA methylation in the placenta. In the present study, we investigated the association between prenatal exposure to several POPs, including organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), and methylation levels of long interspersed element 1 (LINE-1), as well as imprinted genes in placental DNAs among Korean mother-child pairs (N = 109). We assessed the association of DNA methylation not only with each target POP (single-POP models) but also with multiple POPs applying principal component analysis (multiple-POP models). Potential associations between placental DNA methylation and birth outcomes of newborn infants were also estimated. In single-POP models, significant associations were detected between OCP measurements and placental DNA methylation. Elevated concentrations of β-hexachlorhexane (β-HCH) in maternal serum collected during delivery were significantly associated with a decrease in methylation of LINE-1 in the placenta. Higher levels of p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) in maternal serum were associated with hypermethylation of insulin-like growth factor 2 (IGF2). In multiple-POP models, a significant and positive association between DDTs and IGF2 methylation was also observed. Placental LINE-1 methylation was inversely associated with birth length. Our observations indicate that prenatal exposure to several POPs including DDTs is associated with the changes in methylation of genes, including major imprinted genes in the placenta. The consequences of these epigenetic alterations in placenta during development deserve further investigation.

Levels of polybrominated diphenyl ethers in the Korean metropolitan population are declining: A trend from 2001 to 2013

Polybrominated diphenyl ethers (PBDEs) have been banned or voluntarily withdrawn from commerce worldwide. Declining levels of PBDEs in humans have been reported elsewhere, but not in Korea. We monitored 7 individual PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, and BDE-183) in 103 human serum samples collected in 2006. The arithmetic mean and median values for the sum of the 7 PBDEs (∑PBDEs) were 7.13 and 6.70 ng/g lipid, respectively. In addition, 6 pooled human serum samples collected in 2006, 2007, 2009, 2011, 2012, and 2013 were analyzed. A decrease in PBDE levels was observed, as reflected by the median value of ∑PBDEs from 5.98 in 2006 to 2.98 ng/g lipid in 2013 as well as in the pooled samples. The levels of individual congeners also decreased but at different declining rates. Based on these results and previously reported data, a definite decline in PBDE levels in the Korean metropolitan population could be observed from 2001 to 2013, providing the first evidence in Korea of the same decline observed elsewhere in the world. Environ Toxicol Chem 2018;37:2323-2330. © 2018 SETAC.

Association between Organochlorine Pesticide Levels in Breast Milk and Their Effects on Female Reproduction in a Taiwanese Population

Only few studies have focused on organochlorine pesticides (OCPs) in breast milk and the related health risks for women in Taiwan. Our goal is to examine breast milk OCPs and their associations with female reproductive function (infertility, gynecological diseases, and menstruation characteristics) as well as their correlation with sociodemographic parameters (age, pre-pregnant body mass index (BMI), annual incomes, population, birth year, and parity) and dietary habit. The breast milk samples were collected in southern Taiwan (n = 68) from 2013 to 2016 and the OCP residues were analyzed using high resolution gas chromatography with low resolution mass spectrometry (HRGC/LRMS). The results show that the most abundant OCP residues in the breast milk was ΣDDT with the geometric mean ± standard deviation of 9.81 ± 7.52 ng⁻¹ lipid⁻¹ followed by ΣHCH (0.539 ± 0.557 ng⁻¹·lipid⁻¹). In the principal component analysis, cis-chlordane (cis-CHL) and γ-HCH were found to be related to participants who received medical treatment for infertility, and 4,4′-DDT was associated with those who received gynecological surgery. The logistic regression showed that the odds ratio (OR) of log γ-hexachlorocyclohexane (γ-HCH) was higher for mothers who had received medical treatment for infertility than for the normal group (OR = 25.6, p = 0.035) after adjustments for age, pre-pregnant BMI, annual income, population (i.e., native-born Taiwanese), birth year, and parity. Cow milk and beef consumption as well as menstruation characteristics such as average menstrual period (>5 days), shortest menstrual period (<3 days), and women who had taken hormonal drugs were significantly associated to several OCP residues in the breast milk. In addition, ΣHCH including β-HCH and γ-HCH was correlated with annual family income and gravidity as well as cow milk and beef consumptions. Overall, γ-HCH exhibited a probable association with the infertility diseases of Taiwanese women, and dietary habit might play an important role in the female Taiwanese exposure to OCPs.

Current status of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) exposure among mothers and their babies of Korea-CHECK cohort study

Despite the global ban, organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been a persistent and significant environmental health issue worldwide. Prenatal exposure to these persistent organic pollutants (POPs) has been identified as a major route of exposure among developing fetuses and newborn infants. Among Children's Health and Environmental Health of Korea (CHECK) cohort population, pregnant females (n=148) and their matching newborn infants (n=117) recruited from four cities of Korea in 2011 were investigated. The blood serum and cord blood serum were sampled at delivery, and measured for 19 OCPs and 19 PCBs. In addition, a questionnaire regarding demographic characteristics, and dietary habits were conducted. The most frequently detected POPs in both maternal blood and cord blood were p,p'-dichlorodiphenyl dichloroethylene (DDE) (99% detection in maternal, and 98% in cord blood serum) and PCB153 (95% in maternal, 74% in cord blood serum). The levels of dichlorodiphenyl trichloroethanes (DDTs) in both maternal (average 82.5ng/g lw) and cord blood serum (average 77.5ng/g lw) were comparable to or greater than those reported in Japan about a decade ago. Approximately two thirds of the pregnant women and newborn infants showed the p,p'-DDE concentrations exceeding the biological equivalent (BE) corresponding to 10^-6 excess cancer risk. In addition, less chlorinated PCBs were detected higher in both maternal and cord serum. Less chlorinated PCBs also showed greater transplacental ratio. Dairy consumption among the subjects was positively associated, and tea consumption was negatively associated with serum levels of several POPs. Our results show that the exposure to legacy POPs, especially DDTs, among pregnant women and newborn infants is still prevailing, thus warrants measures for exposure mitigation among these vulnerable populations.

Determinants of serum organochlorine pesticide and polychlorinated biphenyl levels in middle-aged Korean adults

The serum levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in a middle-aged Korean population and investigated associations with age, gender, body mass index (BMI), metabolic syndrome (MS), type 2 diabetes mellitus (T2DM), and dietary habits. The median concentrations of 22 OCPs and 34 PCBs in the serum samples were 483 and 216 ng g^-1 lipid, respectively. The most abundant compound was p,p'-DDE, followed by PCB 153, β-HCH, PCB 118, and PCB 180. The results of multiple linear regression and other statistical analyses revealed that serum OCP and PCB levels were higher in women and were positively correlated with age. BMI was positively associated with serum OCP and PCB levels, reflecting the influence of food intake and the preserving effect of body fat. MS and T2DM were significantly associated with serum OCP and PCB levels. The intake of animal foods had positive associations with serum OCP and PCB levels, whereas the intake of phytogenic foods showed negative associations, presumably because of contamination levels in food items and food matrices that governs absorption and excretion of OCPs and PCBs in the body. The relationship between dietary habits and serum OCP and PCB levels were different in participants with MS compared to healthy participants, suggesting MS may alter the influence of food intake on serum OCP and PCB levels.

Association between serum persistent organic pollutants and DNA methylation in Korean adults

BACKGROUND

Exposure to persistent organic pollutants (POPs) has been associated with epigenetic changes such as DNA methylation, which can influence human health. However, the association between POPs and DNA methylation by sex was not shown in previous studies.

OBJECTIVES

We investigated the association between POPs and DNA methylation in men and women using a larger population.

METHODS

A cross-sectional study was conducted using the data of 444 Koreans (253 men and 191 women). Measurements for sixteen different POPs, including six organochlorine pesticides (OCPs) and ten polychlorinated biphenyls (PCBs) were taken in serum. DNA methylation via Alu and LINE-1 in peripheral leukocytes was measured by pyrosequencing. To evaluate the association between POPs and DNA methylation, the Pearson's correlation and multiple linear regression analyses were performed.

RESULTS

Except for PCB52 and PCB101, we found significant inverse associations between p,p'-DDE, cis-Heptachlor epoxide, and PCBs and Alu assay in men after adjusting for age, BMI, smoking status, and alcohol consumption (β = -0.67 for p,p'-DDE; -0.28 for cis-Heptachlor epoxide; in the range from -0.43 to -1.60 for PCBs). In women, PCB153 and PCB180 showed statistically significant inverse association with Alu assay (β = -0.22 for PCB153; -0.22 for PCB180). Except for PCB101, p,p'-DDE and PCBs were positively associated with LINE-1 assay in women (β = 0.48 for p,p'-DDE; in the range from 0.40-0.89 for PCBs) while p,p'-DDE, PCB153, and PCB180 showed positive associations with LINE-1 assay in men (β = 0.55 for p,p'-DDE; 0.65 for PCB153; 1.02 for PCB180).

CONCLUSIONS

We found that several POPs were associated with global DNA hypomethylation in the Alu assay for men and global DNA hypermethylation in the LINE-1 assay for women.

Organochlorine pesticide concentrations in pooled serum of people in different age groups from five Chinese cities

Organochlorine pesticides (OCPs) were determined in human serum samples pooled by donor age (≥60, 50-59, 40-49, 30-39, and 20-29y). The pooled samples were supplied by hospitals in five Chinese cities, Yitong (Jilin Province), Weifang (Shandong Province), Ganzi (Sichuan Province), Huaihua (Hunan Province), and Lingshui (Hainan Province). p,p'-Dichlorodiphenyldichloroethylene (DDE), hexachlorobenzene (HCB), β-hexachlorocyclohexane (HCH), and endosulfan I were the dominant OCPs in the serum samples. The total OCP concentrations and individual concentrations of p,p'-DDE, HCB, and β-HCH were relatively high compared with concentrations that have been found in other parts of the world. The total OCP, p,p'-DDE, and β-HCH concentrations decreased as age decreased but the HCB and endosulfan I concentrations were slightly higher in the samples from younger donors than in samples from older donors. HCB must be currently used and have new sources to people to cause this. Chinese government policies and the characteristics of the OCPs have led to OCP concentrations in serum decreasing with decreasing age. Different OCP usage patterns in different Chinese cities have led to the inhabitants of different cities having different OCP distributions in their serum.

Risk profile and health vulnerability of female workers who pick cotton by organanochlorine pesticides from southern Punjab, Pakistan

The present study was conducted to highlight the existing level of organochlorine-pesticides (OCPs) from human milk (n = 45) and blood serum (n = 40) of female workers who pick cotton in Khanewal District, southern Punjab, Pakistan. Source apportionment, congener-specific analysis, and risk surveillance of OCPs are reported from human milk and blood samples. Levels of OCPs in milk and blood serum samples ranged from 15.7 ppb to 538.3 ppb and from 16.4 ppb to 747.1 ppb, respectively, and were lower than previously published reports from other regions of the globe. Congener-specific analysis revealed that DDTs were predominant, followed by hexachlorocyclohexane, chlordane, and hexachlorobenzene. Calculated results for source apportionment analysis suggested that contamination load was a new input of DDTs as well as the historic use of lindane in the study area. Levels of OCPs in milk and blood serum were significantly (p < 0.05) correlated with age, time period of picking cotton, and number of children. Health risk revealed that female workers had risk of cancer among 1 per million; however, noncarcinogenic risks were not considerable. Environ Toxicol Chem 2017;36:1193-1201. © 2016 SETAC.

Exposure to the insecticide endosulfan induces liver morphology alterations and oxidative stress in fruit-eating bats (Artibeus lituratus)

Exposure to pesticides may increase the generation of reactive oxygen species (ROS), leading to oxidation of cell membrane lipids and proteins. Although fruit bats are potentially exposed to pesticides during their entire lifespan, the impacts of this exposure are still poorly investigated. We examined the effects of low, commercially recommended concentrations (0, 1.05 and 2.1 g/l) of an organochlorine insecticide endosulfan (EDS) formulation on oxidative responses in the liver and kidneys of Neotropical fruit bats (Artibeus lituratus), as well as possible liver morphological alterations following a 35-day oral exposure. Superoxide dismutase activity was significantly decreased upon exposure to 1.05 g/l of EDS in the liver and kidneys, catalase was decreased in the liver of 2.1 g/l EDS-exposed bats, while glutathione S-transferase was increased in the liver of 2.1 g/l EDS-exposed bats. Protein carbonyls increased following the exposure to the highest EDS dose tested. Endosulfan-induced morphological alterations in the liver included cell degeneration and cell death, with apparent cytoplasm lipid accumulation (steatosis) and pyknotic nuclei, karyolysis and deposit of collagen fibres. Our findings suggest that exposure to low concentrations of EDS induced a certain extent of oxidative damage in fruit bats, which may have led to liver morphological alterations.

Association between serum concentrations of persistent organic pollutants and smoking in Koreans: A cross-sectional study

Background

Studies on the associations between persistent organic pollutants (POPs) and smoking according to gender and smoking amount (cigarettes/day) are limited, and the results regarding the relationship between POPs and smoking are not completely consistent across studies.

Objectives

The smoking rate in Korea is one of the highest among the Organization for Economic Cooperation and Development (OECD) countries. We investigated the association between serum concentrations of POPs and cigarette smoking in Koreans by smoking status (never-smoker/ever-smoker) and smoking amount (cigarettes/day) according to gender.

Methods

Serum concentrations of 32 polychlorinated biphenyls (PCBs) and 19 organochlorine pesticides (OCPs) were measured in 401 participants (232 men and 169 women) who received health examinations during the Korean Cancer Prevention Study-II. We compared POP levels in ever-smokers and never-smokers and conducted multivariate logistic regression analyses to identify associations between POPs and smoking.

Results

Among women, the concentrations of PCB 156, PCB 167, and PCB 180 were significantly higher in ever-smokers than in never-smokers. After adjustments for age, body mass index, gamma-glutamyl transpeptidase, and alcohol intake, serum PCB 157 concentration was positively associated with male ever-smokers (OR 2.26; 95% CI, 1.01–5.04). In addition, trans-nonachlordane in OCPs as well as PCBs was significantly positively related with female ever-smokers (OR 3.21; 95% CI, 1.04–9.86). We found that subjects who smoked fewer than 15 cigarettes/day had a higher risk of having high POP concentrations than never-smokers.

Conclusions

These results indicate that smoking may be associated with human serum POPs levels.

Polybrominated Diphenyl Ethers in Maternal Serum, Breast Milk, Umbilical Cord Serum, and House Dust in a South Korean Birth Panel of Mother-Neonate Pairs

Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants. Although many reports have indicated an association between exposure to PBDEs and developmental neurotoxicity, the relative contributions of different sources of dust PBDE congeners to the levels in various tissues of mother–baby pairs is not well understood. The aims of this study were thus to measure the quantitative relationship between the level of PBDEs in house dust and tissues of mother-neonate pairs, and to investigate the chemical sources of the PBDEs. Forty-one mother-neonate pairs were recruited and provided samples of maternal serum (n = 29), umbilical cord serum (n = 25), breast milk (n = 50), and house dust (n = 41), where PBDEs were determined with high-resolution gas chromatography coupled with high-resolution mass spectrometry. While deca- (e.g., BDE 209, detected 100%), nona- (BDE 206/207, 95.1%), octa- (BDE 183, 100%), penta- (BDE 99/153, 100%, 98%) and tetra-BDEs (BDE 47, 100%) were detected abundantly in dust, penta- (BDE 99, 76%, 92%) and tetra-BDEs (BDE 47, 84%, 98%) were detected abundantly in umbilical cord serum and breast milk, respectively; tetra-BDEs (BDE 47, 86%) were detected more often relative to other congeners in maternal serum. Spearman’s pairwise comparison showed that the levels of BDE 47 (ρ = 0.52, p < 0.001) and −99 (ρ = 0.64, p < 0.01) in umbilical cord serum were associated with BDE 209 levels in dust; BDE 47 in maternal serum also showed correlation with BDE 99 in cord serum (ρ = 0.48, p < 0.01) but there was no significant correlation between maternal BDE 47 and dust BDE 209. On the other hand, a comparison of the distribution among congeners suggested probable associations of BDE 47 in maternal serum, breast milk, and umbilical cord serum with BDE 209 in dust; and of BDE 99 in maternal and umbilical cord serum, breast milk, and dust with BDE 209 in dust. Although further studies are needed, a radar chart-based distributional comparison among congeners supported associations between BDE 47 or −99 in human tissues and BDE 209 in dust.

Organohalogenated contaminants in type 2 diabetic serum from Jeddah, Saudi Arabia

Most of the organohalogenated contaminants (OHCs) have high environmental stability and are lipophilic in nature, thus bioaccumulate through the various routes e.g., inhalation, dermal contact and food intake. Human exposure to these OHCs can induce adverse health effects. Studies on the occurrence of OHCs in human samples from Saudi Arabia are scarce. Therefore, this study aimed at providing preliminary insight on the occurrence of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated biphenyl ethers (PBDEs) in diabetic and non-diabetic donors from KSA. Serum samples were collected from type 2 diabetic patients (n = 40) and control donors (n = 20) to study the impact of OHCs on their health. For the first time we studied the difference of ƩOHCs in type 2 diabetic and control participants. The order of obtained results was ƩOCPs (35-650 ng/g lw)> ƩPCBs (15-90 ng/g lw)> ƩPBDEs (1.5-68 ng/g lw). The major contributors were p,p'-DDE (median 44 ng/g lw), PCB 153 (2.3 ng/g lw), PCB 138 (2.1 ng/g lw), BDE 153 (1.2 ng/g lw) and BDE 47 (0.85 ng/g lw). Exposure to different OHCs between male and female donors was not significantly different (p > 0.05). However, ƩPCBs and ƩOHCs were significantly higher (p < 0.05) in diabetic donors than those of control group. We computed significantly positive correlations (p < 0.05) among different OHCs and between OHCs and age factor. The current study highlights the presence of different OHCs in humans from Jeddah, KSA. This is a preliminary study based on small sample size but our results suggested that detailed studies are required to understand the sources of these pollutants and their impact on human health.

Exposure and risk assessment of the Czech population to chlorinated pesticides and polychlorinated biphenyls using archived serum samples from the period 1970 to 1990

The serum samples from the years 1970-1990 archived at the temperature of -20°C in the biobank primarily intended for serological survey performed in the CR since 1960 were pooled and analyzed for DDT, its metabolites, HCB, HCHs, and indicator PCB congeners using up-to-date GC/MS/MS methods to retrospectively assess health risks according to current health guidelines. Samples were pooled based on the decade of sampling, age, gender, and three geographical areas; in adults, one pooled samples consisted of ten and in children of twenty individual samples. Altogether 233 pooled samples were analyzed. For all organochlorine pesticides (OCPs), significant downward trends were observed in the period 1970-1990 (p<0.001). The levels of HCB exceeded the Biomonitoring Equivalent (BE) value. The hazard quotient (HQ) in Prague and Ostrava during the 1970s and 1980s was about 40 and in the 1990s it had dropped to about five. In Uherské Hradiště, the HQ in 1975 was one order of magnitude higher (about 170), and had decreased to approximately 12 by 1987. For both HCB and the DDT sum, the BE-related carcinogenic risk of actual concentrations in the past exceeded significantly the individually accepted cancer risk level of 10(-4). The levels of the main PCB congeners in the 1970s through 1990s revealed an upward time trend in all analyzed strata. The highest concentrations were found in the serum of residents from the hot-spot area Uherské Hradiště. Critical PCB sum concentration levels (700ng/g lipid for vulnerable population groups and 1800ng/g lipid for other population groups) were substantially exceeded with an increasing time trend. PCB sum had exceeded HBM II values of 7μg/L of serum since 1980 in all age strata. In conclusion, the body burden of the Czech general population relative to persistent organic pollutants (POPs) in the period 1970 through 1990 significantly exceeded currently existing health based limit values. The past exposure might adversely affect the health status of the Czech population.

Occurrence and prenatal exposure to persistent organic pollutants using meconium in Korea: Feasibility of meconium as a non-invasive human matrix

Prenatal exposure to persistent organic pollutants (POPs) is of great concern due to the vulnerability of fetus. Nineteen Polychlorinated biphenyls (PCBs), 18 organochlorine pesticides (OCPs) including DDTs, HCHs, chlordanes, and hexachlorobenzene, and 22 polybrominated diphenyl ethers (PBDEs) were measured in meconium samples from 72 newborn infants using high resolution gas chromatography/mass spectrometry. The median concentrations (on wet weight basis) of PCBs, OCPs, and PBDEs were 26.8pg/g, 66.7pg/g, and 2.32pg/g, respectively. Highly significant correlations were observed among the compounds of PCBs and OCPs, suggesting their similar sources and kinetic behaviors. BDE 47 had significant correlations with PCBs and OCPs, whereas BDE 209 was not correlated with any of the contaminants due to different exposure sources. The concentrations of p,p'-DDE, β-HCH, and trans-nonaCHL between paired maternal blood-meconium and cord blood-meconium showed significant correlations, while PCBs and PBDEs were not significantly correlated in the paired samples. Maternal age and gestational age were demographic parameters affecting POP levels in meconium. Multiple regression analysis showed that the levels of several OCPs in cord and maternal serum were contributing factors governing the levels of these contaminants in meconium. Our results indicate that meconium can be utilized as a human matrix for prenatal exposure to several OCPs.

Internal exposure levels of typical POPs and their associations with childhood asthma in Shanghai, China

Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are common persistent organic pollutants (POPs) that may be associated with childhood asthma. The concentrations of PBDEs, PCBs and OCPs were analyzed in pooled serum samples from both asthmatic and non-asthmatic children. The differences in the internal exposure levels between the case and control groups were tested (p value <0.0012). The associations between the internal exposure concentrations of the POPs and childhood asthma were estimated based on the odds ratios (ORs) calculated using logistic regression models. There were significant differences in three PBDEs, 26 PCBs and seven OCPs between the two groups, with significantly higher levels in the cases. The multiple logistic regression models demonstrated that the internal exposure concentrations of a number of the POPs (23 PCBs, p,p'-DDE and α-HCH) were positively associated with childhood asthma. Some synergistic effects were observed when the children were co-exposed to the chemicals. BDE-209 was positively associated with asthma aggravation. This study indicates the potential relationships between the internal exposure concentrations of particular POPs and the development of childhood asthma.

Serum concentrations of PCBs and OCPs among prepubertal Korean children

Although children are more vulnerable than adults to environmental hazards, due to their physiological and behavioral characteristics, few studies have assessed their internal exposure to persistent organic pollutants (POPs). The objective of this study was to determine the serum levels of certain polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) among pre-pubertal children in Korea and examine their variation with age and gender. We analyzed a total of 51 POPs in 214 children (age range, 7-9 years), using data from the Ewha Birth and Growth Cohort Study. To examine change over time, POP concentrations were measured at both 7 and 9 years of age in a sub-cohort of 26 children. The median and interquartile range (IQR, 25th to 75th percentiles) data for the sum of PCB congeners was 26.44 ng/g lipid (18.27-37.63 ng/g lipid). The median (IQR) concentration for the sum of OCPs was 74.82 ng/g lipid (51.11-112.45 ng/g lipid). Our results showed significant increases in serum concentrations of total PCBs with age (p = 0.0001), no gender dependence of total PCBs (p = 0.38) and total OCPs (p = 0.12), and strong correlations between individual POPs. Childhood exposure to POPs was relatively low compared to other studies carried out in different countries. However, even though the use of POPs has been banned since 2001, our results indicated that children in the general population are still exposed to various POPs. Because long-term, low-level exposure to POPs in the general population remains a concern for human health, future research should examine major routes of exposure and identification of risk factors.

Levels and predictors of persistent organic pollutants in an adult population from four Spanish regions

This research aimed to assess serum concentrations of a group of persistent organic pollutants (POPs) in a sample of adults recruited in four different regions from Spain and to assess socio-demographic, dietary, and lifestyle predictors of the exposure. The study population comprised 312 healthy adults selected from among controls recruited in the MCC-Spain multicase-control study. Study variables were collected using standardized questionnaires, and pollutants were analyzed by means of gas chromatography with electron capture detection. Multivariable analyses were performed to identify predictors of log-transformed pollutant concentrations, using combined backward and forward stepwise multiple linear regression models. Detection rates ranged from 89.1% (hexachlorobenzene, HCB) to 93.6% (Polychlorinated biphenyl-153 [PCB-153]); p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) showed the highest median concentrations (1.04ng/ml), while HCB showed the lowest (0.24ng/ml). In the multivariable models, age was positively associated with HCB, p,p'-DDE, and PCB-180. BMI was associated positively with p,p'-DDE but negatively with PCB-138. Total accumulated time residing in an urban area was positively associated with PCB-153 concentrations. The women showed higher HCB and lower p,p'-DDE concentrations versus the men. Notably, POP exposure in our study population was inversely associated with the breastfeeding received by participants and with the number of pregnancies of their mothers but was not related to the participants' history of breastfeeding their children or parity. Smoking was negatively associated with HCB and PCB-153 concentrations. Consumption of fatty foods, including blue fish, was in general positively associated with POP levels. Although POP environmental levels are declining worldwide, there is a need for the continuous monitoring of human exposure in the general population. The results of the present study confirm previous findings and point to novel predictors of long-term exposure to persistent organic pollutants.

Blood levels of polychlorinated biphenlys and organochlorinated pesticides in women from Istanbul, Turkey

The human body is not a chemically uncontaminated system. Every simple action that humans undertake, such as drinking water, eating, nursing, and even breathing air, puts the system under environmental xenobiotic exposure stress. Environmental chemicals have been shown to produce unwanted effects on health and remove the right to healthy living, starting from the first encounter in utero to geriatrics, throughout the lifespan. Organochlorine pesticides (OCPs) and polychlorinated biphenyl (PCB) levels, important members of the persistent organic pollutants (POPs), have been detected before in human breast milk and also in the adipose tissue of women from different regions of Turkey; however, there was no information about the blood levels of these chemicals. This study generated the first information that evaluates OCP and PCB contamination levels in the blood of the women living in Turkey. The current study measured the blood concentrations of OCPs and PCBs in 58 healthy women (age 20-41 years; mean age 28 years) who were living in Istanbul, Turkey, in the years 2010-2012. Samples were analyzed for 29 OCPs and 18 PCB congeners using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS). PCB 153 was the predominant congener (643.2 pg/g lipid), followed by PCB 138 and PCB 180. 4,4'-DDE (24872.8 pg/g lipid) was the most common organochlorinated pesticide contaminant in studied blood samples. Results for analyzed chlorinated compounds were as follows: ∑PCB 2682 ± 3300 pg/g lipid; ∑DDT 25,938 ± 28,644 pg/g lipid; and ∑HCH 2930 ± 2222 pg/g lipid, respectively. The mean concentration of ∑WHOPCB-TEQ was 0.037 pg/g on a lipid basis. This information will be important base data during the assessment of the general health concerns of women, as well as for studies about how endocrine disruptors affect humans for forthcoming studies.

DDT and its metabolites are linked to increased risk of type 2 diabetes among Saudi adults: a cross-sectional study

Organochlorine (OC) pesticides have recently been associated with type 2 diabetes in several non-Asian general populations. As there is currently an epidemic of type 2 diabetes mellitus in Asia. The prevalence and incidence of diabetes is increasing rapidly worldwide including many Arab Gulf countries. According to a community-based national epidemiological health survey, the overall prevalence of diabetes mellitus in Saudi adults (age group of 30-50 years) is 23.7%. A recent study by Al-Daghri et al. (BMC Med 9:76, 2011) reported that the prevalence of diabetes mellitus in the Kingdom of Saudi Arabia (KSA) is 31.6%. We investigated the associations between OC pesticides and type 2 diabetes in Saudi Arabia using a simple, sensitive, rapid, and selective gas chromatography coupled with mass spectrometry (GC-MS) method that has been recently developed. A total of 280 Saudi adults (136 diabetes mellitus (DM) patients and 144 non-DM controls) were randomly selected from the Riyadh Cohort Study for inclusion. The diagnosis of diabetes was based on established diagnosis and medications taken. Blood dichlorodiphenyltrichloroethane (DDT) and its derivatives were quantified using GC-MS. Residues of DDT and its derivatives were analyzed in serum by means of gas chromatography with a mass spectrometry detector. Associations between DDT exposure and T2DM were analyzed by logistic regression. DDT and its derivatives and serum concentrations of DDT and its derivative DDE showed the strongest and most significant association to type 2 diabetes in both cross-sectional and prospective studies. Associations of DDT and its derivatives varied across different diabetes-related components of the metabolic syndrome. It positively and significantly associated with four of the five of these components especially elevated triacylglycerol, high fasting glucose, high blood pressure, and HOMA-IR but negatively and significantly with HDL. Possible biological mechanisms are discussed. This study confirms previous reports relating organochlorine pesticide (OCP) exposure to diabetes and suggests possible hormonal pathways deserving further exploration. The study will be one of the first to shed light on the associations of serum levels of total DDTs and DDT derivatives among the Saudi Arab ethnicity, and diabetes type 2 chronic noncommunicable diseases are highly prevalent.

Levels and profile of several classes of organic contaminants in matched indoor dust and serum samples from occupational settings of Pakistan

Dust ingestion is an important route of human exposure to organic contaminants, especially for flame retardants (FRs) in occupational settings. Several classes of organic contaminants were analyzed in matched dust and serum samples from academics and workers in electronics and clothing stores of Faisalabad, Pakistan. The concentrations of contaminants varied in dust as follow: organophosphate FRs (∑PFRs) > novel brominated FRs (∑NBFRs) > polybrominated diphenyl ethers (∑PBDEs) > organochlorine pesticides (∑OCPs) > polychlorinated biphenyls (∑PCBs), while, in serum, concentration varied: ∑OCPs > bromophenols (∑BPs) > ∑PCBs > ∑HO-PCBs ≈ ∑PBDEs. Two NBFRs, namely 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE) and bis(2-ethylhexyl) tetrabromophthalate (TBPH), were detected in <10% of the serum samples. p,p'-DDE was the major contaminant in serum contributing to ∼75% of the total contaminant burden. Levels of Penta-BDE congeners in serum and dust were significantly correlated (r = 0.64, p < 0.01) for the academics, suggesting dust ingestion as an important determinant for their serum levels.

Occurrences of major polybrominated diphenyl ethers (PBDEs) in maternal and fetal cord blood sera in Korea

Polybrominated diphenyl ethers (PBDEs) are of growing public health concern because of their potential toxicities which range from endocrine disruption to neurodevelopment. However, information on their exposure among sensitive human populations is limited. The objectives of this study were to determine the levels of major PBDEs in blood sera of pregnant women and their matching newborn infants. For this purpose, a total of 198 maternal blood samples and 118 matching umbilical cord blood samples were collected from four regions of South Korea in 2011, and were determined for 19 PBDE congeners. Various demographic, dietary, and behavioral characteristics were asked in a questionnaire survey. Average concentration of total PBDEs in maternal blood serum was 3.34 ± 8.42 ng/g lipid weight (lw) at delivery and 3.14 ± 7.46 ng/g lw at 6 months of pregnancy, respectively. In cord blood serum, an average of 9.37 ± 12.60 ng/g lw was detected. Among the measured PBDE congeners, BDE-47, BDE-99 and BDE-153 were most dominant in both maternal and cord blood sera. Relatively higher levels of BDE-99 were detected in cord blood serum. Strong positive correlations were detected between maternal and cord blood serum samples, indicating the importance of maternal transfer. Health consequences of transplacental exposure to PBDEs among fetuses and newborn infants warrant further investigation.

Distribution and bioaccumulation of polychlorinated biphenyls and organochlorine pesticides residues in sediments and Manila clams (Ruditapes philippinarum) from along the Mid-Western coast of Korea

The distribution and bioaccumulation features of PCBs, DDTs, and HCHs were investigated in the sediments and Manila clams collected from along the Mid-Western coast of Korea. The measured concentrations of ΣPCBs, ΣDDTs and ΣHCHs were 1.08-3.5, 0.12-0.35 and 0.090-0.30 ng g(-1) dw in sediment, and 33-390, 7.4-46 and 6.3-27 ng g(-1) lipid in Manila clam, respectively. Their levels were found to be relatively lower than those of other contaminated areas and the consumption of Manila clam from these areas seems to be safe for human health according to calculated lifetime cancer risk and hazard indices. The ΣPCBs and ΣDDTs concentrations in sediments showed a significant relationship to those in clams. The significant correlation was observed between BSAF in clams and Kow for each PCB congeners and DDT metabolites. These findings support that the PCBs and DDTs levels, which are highly hydrophobic chemicals, in clam reflect the sediment pollution through bioaccumulation.

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.

Genetic variation in the CYP1A1 gene is related to circulating PCB118 levels in a population-based sample

Several of the polychlorinated biphenyls (PCBs), i.e. the dioxin-like PCBs, are known to induce the P450 enzymes CYP1A1, CYP1A2 and CYP1B1 by activating the aryl hydrocarbon receptor (Ah)-receptor. We evaluated if circulating levels of PCBs in a population sample were related to genetic variation in the genes encoding these CYPs. In the population-based Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) study (1016 subjects all aged 70), 21 SNPs in the CYP1A1, CYP1A2 and CYP1B1 genes were genotyped. Sixteen PCB congeners were analysed by high-resolution chromatography coupled to high-resolution mass spectrometry (HRGC/ HRMS). Of the investigated relationships between SNPs in the CYP1A1, CYP1A2 and CYP1B1 and six PCBs (congeners 118, 126, 156, 169, 170 and 206) that captures >80% of the variation of all PCBs measured, only the relationship between CYP1A1 rs2470893 was significantly related to PCB118 levels following strict adjustment for multiple testing (p=0.00011). However, there were several additional SNPs in the CYP1A2 and CYP1B1 that showed nominally significant associations with PCB118 levels (p-values in the 0.003-0.05 range). Further, several SNPs in the CYP1B1 gene were related to both PCB156 and PCB206 with p-values in the 0.005-0.05 range. Very few associations with p<0.05 were seen for PCB126, PCB169 or PCB170. Genetic variation in the CYP1A1 was related to circulating PCB118 levels in the general elderly population. Genetic variation in CYP1A2 and CYP1B1 might also be associated with other PCBs.

Assessment of Dechlorane compounds in foodstuffs obtained from retail markets and estimates of dietary intake in Korean population

A total of 175 samples, composed of 35 different foodstuffs, were obtained from retail markets in Korea and analyzed to investigate the contamination status and dietary intake of Dechlorane compounds. The concentrations of Dechlorane Plus (DP), mirex, Dechlorane (Dec) 602 and 603 ranged from ND to 169.85 pg/g wet weight (ww), 107.30 pg/g ww, 20.81 pg/g ww, 0.41 pg/g ww, respectively, while Dechlorane (Dec) 604 was not detected in any samples. Strong correlations between anti- and syn-DP and between mirex and Dec 602 were observed. The average anti-isomer fractional abundance (fanti) was 0.78±0.11 which was larger than the technical DP value (fanti=0.75). The estimated dietary daily intake of DP, 11.2×10(3) pg/day, was one to three orders of magnitude higher than other Dechloranes. Grain was the most contributed food group to dietary daily intake of DP for Korean population.

Impacts of atmospheric chlor-alkali factory emissions in surrounding populations

Environmental exposures need to be assessed for the understanding of the health risks of general population. Organochlorine compounds (OCs) from chlor-alkali plants (CAPs) are significant for the exposomes of individuals living in locations receiving their emissions and have to be determined. The aims of the study are to identify the area of influence of past and present OC emissions from CAPs and to set quantitative body burden estimates. A CAP situated in a rural area was selected for study. The geographic distribution of the atmospheric emissions was monitored using olive tree leaves. Human biomonitoring was assessed by serum analysis from general population (n=1340). OC concentrations followed exponential decay functions with maxima in the immediate vicinity of the factory. The individuals living within 1km exhibited hexachlorobenzene (HCB), polychlorobiphenyls (PCBs) and DDT-DDE (dichlorodiphenyltrichloroethane-dichlorodiphenyldichloroethylene) concentrations that were 12, 1.3-1.9 and 3.9 times higher than in sites not influenced by the emissions from this factory. Individuals from municipalities situated 15-25km away from the CAP showed 1.5, 1.2-1.4 and 1.3 times higher serum HCB, PCB and DDT concentrations than in distant sites. The high serum concentrations of DDT and PCBs were observed even 23-31years and 9-17years after manufacture completion of these compounds, respectively. Our methodology provides a way for assessment of the influence of past and present atmospheric OCs emissions from CAPs into the exposome of individuals living in nearby areas.

Serum levels of organochlorine pesticides in the French adult population: the French National Nutrition and Health Study (ENNS), 2006-2007

BACKGROUND

Although most organochlorine (OC) pesticides were banned in France in the 1970s and 1980s, they remain a source of public concern. Because of their high persistence in the environment, they are still detected in foodstuffs, leading to continued human exposure. The purpose of this study was to assess the distribution of serum organochlorine (OC) pesticides in the French adult population and to identify the main risk factors for p,p'-dichlorodiphenyl dichlorethylene (DDE), β-hexachlorocyclohexane (β-HCH) and hexachlorobenzene (HCB).

METHOD

The selected OC pesticides (HCB, DDE, DDT, α-HCH, β-HCB and γ-HCH) were measured in serum samples collected in 2006-2007 from 386 persons (aged 18-74 years) randomly selected among the participants in the clinical and biological component of the French Nutrition and Health Survey (Etude Nationale Nutrition Santé [ENNS]), a cross-sectional survey carried out in the general population. Collected data included biological samples, socio-demographic characteristics, and data about environmental and occupational exposure factors.

RESULTS

Of the six OC pesticides investigated, the highest concentrations were observed for HCB, β-HCH and DDE. Median serum concentrations were as follows: 22.8 ng/g lipid for HCB, 0.74 and 27.0 ng/g lipid, respectively, for α- and ß-HCH, and 3.8 and 104.6 ng/g lipid, respectively, for DDT and DDE. Lindane (γ-HCH) was detected in approximately 10% of the sample. OC pesticide levels in serum in French adults were higher (except for DDT and DDE) than those observed in American, Canadian and German populations and generally lower than or in the same range as those observed in other European countries. The low serum DDT/DDE ratio in the present study (3.7%) would suggest that the concentrations observed for these two OC pesticides were mainly the result of past exposure. The most important predictors of serum DDE, HCB and β-HCH concentrations among the French adult population included individual factors (age, gender, BMI, etc.), dietary factors of animal and vegetable origin, and domestic use of pesticides (in vegetable gardens and/or fruit trees).

CONCLUSION

For the first time in France, a human biomonitoring study has shown that exposure to OC pesticides remains common in the population. French concentrations were higher (except for DDT and DDE) or were similar to those observed in other developed countries.

Occurrence and exposure assessment of polychlorinated biphenyls and organochlorine pesticides from homemade baby food in Korea

Data on the residue levels of persistent organic pollutants (POPs) in baby food samples are scarce. This is the first study to explore current contamination status and exposure assessment of organochlorines (OCs), including polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs), in baby food from Korea. In this study, the concentrations of OCs were determined in homemade baby food samples (n=100) collected from 6-, 9-, 12- and 15-month-old infant groups. The average concentrations of PCBs, dichloro-diphenyl-trichloroethanes (DDTs), hexachlorocyclohexanes (HCHs) and chlordanes (CHLs) in baby food samples were 37.5, 96.6, 26.0, and 13.2 pg/g fresh weight, respectively. The major compounds were CBs 28, 153, 52, and 33 for PCBs and p,p'-DDE, p,p'-DDT and β-HCH for OCPs. The contribution of DDTs to the total OC concentrations increased from 30% (6-month-old infants) to 67% (15-month-old infants) with increasing infant age, while the concentrations of PCBs, HCHs and CHLs gradually decreased with increasing infant age, suggesting that highest priority for risk reduction of DDTs. The estimated daily intakes (EDIs) of OCs in Korean infants from baby food consumption were lower than the thresholds proposed by the United States Environmental Protection Agency and Health Canada, implying limited potential health risks. However, considering simultaneous exposure from baby food and breast milk consumption, chlordanes and heptachlor epoxide posed potential health risks. Considering the importance of early development and the vulnerability of infants, it is essential to perform systematic monitoring and management programs of OCs in baby food for risk reduction in Korean infants.

Contamination of polychlorinated biphenyls and organochlorine pesticides in breast milk in Korea: time-course variation, influencing factors, and exposure assessment

Breast milk is a noninvasive specimen to assess maternal and infant exposure to polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). In this study, 206 breast milk samples were collected from 87 participants during lactation, at <7, 15, 30, or 90 days postpartum in four cities in Korea. The total concentrations of PCBs (ΣPCB) and OCPs (ΣOCP) ranged from <LOQ to 84.0 (median: 12.1) ng g(-1) lipid weight and from <LOQ to 559 (median: 144) ng g(-1) lipid weight, respectively. The residue levels of these contaminants measured in our study were relatively lower than those reported for European, African and Asian populations. Within a month postpartum typically after day seven the levels of ΣPCB and ΣOCP significantly increased. Some OCP compounds were correlated with maternal age, BMI, parity, and delivery mode. Certain types of dietary habits such as seafood and noodle consumption were significantly associated with ΣPCB and ΣOCP. The estimated daily intakes (EDIs) of ΣPCB and ΣOCP were 45.2-127 ng kg(-1) bw day(-1) and 625-1259 ng kg(-1) bw day(-1) during lactation, respectively, which are lower than the threshold values proposed by the US EPA and Health Canada. The exposure of Korean infants to chlordanes via breast milk had a potential health risk which deserves further investigation.

Polybrominated diphenyl ethers (PBDEs) in breast milk of Korea in 2011: current contamination, time course variation, influencing factors and health risks

Breast milk is a valuable biological specimen to assess maternal and infant exposure to polybrominated diphenyl ethers (PBDEs). In this study, 208 breast milk samples were collected from 89 participants during lactation period, at <7, 15, 30, and 90 days postpartum, in four cities in Korea, and were determined for 19 PBDE congeners. The total PBDE concentrations (ΣPBDE) ranged from 0.23 to 68.4 (mean: 2.73) ng/g lipid weight, and were within the ranges reported for European and Asian countries. Within a month of lactation after delivery, no significant changes were found in the PBDE concentrations. The predominance of BDE 153 rather than BDE 47 was found in the most samples that BDE 153 was detected, and was likely to be associated with stepwise debromination of BDE 209. No associations were found between PBDE concentrations in breast milk and demographic parameters, except for ΣPBDE with maternal age and delivery mode. Certain types of diet such as corn, seafood and nut correlated significantly with PBDE levels in breast milk. The estimated daily intakes of ΣPBDE for breast-feeding infants were lower than the guidelines proposed by the US EPA, indicating limited health risk from PBDEs through breast feeding.

Organohalogenated contaminants (OHCs) in human serum of mothers and children from Pakistan with urban and rural residential settings

This study aimed to provide first data on the concentrations of different classes of organohalogenated contaminants (OHCs) in human serum from Pakistan, an area with limited information on environmental pollution. Serum samples (N=85) were collected from mothers (N=34; age ranged 23-51 years), their children (N=34; age 3-10 years) and general group (N=17; age 13-65 years) with rural and urban residential settings. The concentrations of studied OHCs in serum decreased as follows: organochlorinated pesticides (OCPs)>polychlorinated biphenyls (PCBs)>polybrominated diphenyl ethers (PBDEs). Novel brominated flame retardants (NBFRs) were not detected, except for 1,2-bis(2,4,6-tribromophenoxy)-ethane (BTBPE)<0.2-8 ng/g lipid weight (lw). Low levels of HO-PCBs (<0.2-20 ng/g lw) were detected, while HO-PBDEs were <0.2 ng/g lw. ∑PCBs (2-105 ng/g lw) together with ∑PBDEs (0.2-6.7 ng/g lw) contributed ~5% of the total OHCs body burden. The concentration(s) of major contributors (>80%) of OCPs ranged from <1-3645 ng/g lw for 1,1'-bis-(4-chlorophenyl)-2,2-dichloroethene (p,p'-DDE), <1-445 ng/g lw for β-hexachlorocyclohexane (β-HCH) and from 5 to 200 ng/g lw for pentachlorophenol (PCP). p,p'-DDE, the major OHC, was significantly higher (p<0.05) in rural children than in all other groups. In serum of rural children, the major OHCs were significantly higher (p<0.05) than the mothers. The current study indicates continuous exposure to humans with already regulated OHCs and highlights the need for further monitoring of these OHCs in the region.

Human exposure to p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in urban and semi-rural areas in southeast Spain: a gender perspective

p,p'-Dichlorodiphenyldichloroethylene (p,p'-DDE) is the main metabolite of pesticide dichlorodiphenyltrichloroethane and a marker of past exposure to this organochlorine pesticide. p,p'-DDE is considered a persistent organic pollutant with potential adverse effects on human health. The aims of the present study were to assess p,p'-DDE levels in serum and adipose tissue from a cohort of adults in southern Spain and to explore the predictors of exposure from a gender perspective. Chemical analyses were performed using gas chromatography-coupled mass spectrometry in tandem mode. The study population (n=387) was intraoperatively recruited in two areas of Granada Province (southern Spain), and data on potential predictors of these concentrations were gathered by questionnaire. The statistical analysis was performed by means of multivariable linear regression models. All participants showed detectable concentrations of p,p'-DDE in both serum and adipose tissue, with median concentrations of 175.7 and 93.0 ng/g lipid, respectively (p<0.001), and the two measurements showed positive correlations. Women showed higher concentrations than men (115.8 and 66.2 ng/g lipid, respectively, p<0.001). Concentrations in both matrices were positively associated with fatty food consumption, as well as with age and BMI, the latter only in adipose tissue. The multivariate model showed that, among women, adipose tissue concentrations were approximately 40% higher in those residing in the semi-rural area and 2-fold higher in those whose mothers had participated in agricultural activities during the pregnancy. In this study population, gender and place of residence play a key role in human exposure to p,p'-DDE and can be used to identify subjects at special risk of long-term exposure.

Exposure to priority organochlorine contaminants in the Italian general population. Part 1. Eight priority organochlorinated pesticides in blood serum

Despite extensive use of organochlorinated pesticides (OCPs) such as dichlorodiphenyltrichloroethane (DDT) in Italy in the 1940s to 1970s, especially for public health control of malaria mosquitoes, information on their exposure levels among the general population is limited. These OCPs can be a source of health risk to human. A total of 137 blood samples were collected from residents of the general population of three Italian towns, Novafeltria, Pavia and Milan, to determine the levels of eight OCPs in blood serum. The concentrations of beta-hexachlorocyclohexane, hexachlorobenzene (HCB), 1,1-dichloro-2-( o-chlorophenyl)-2-( p-chlorophenyl)ethylene, 1,1-dichloro-2,2-bis( p-chlorophenyl)-ethylene ( p, p' -DDE), 1,1-dichloro-2-( o-chlorophenyl)-2-( p-chlorophenyl)ethane, 1,1-dichloro-2,2-bis (4-chlorophenyl)ethane, 1,1,1-trichloro-2-( o-chlorophenyl)-2-( p-chlorophenyl)-ethane and 1,1,1-trichloro-2,2-bis( p-chlorophenyl) ethane were measured by gas chromatography–mass spectrometry. Variations in serum concentrations of OCPs with respect to place of residence, gender, age and body mass index (BMI) were evaluated by non-parametric tests. p, p' -DDE and HCB were the most abundant and major contributors of total OCP concentration. Their levels differed significantly between the three towns with a trend Milan > Novafeltria > Pavia (  p < 0.0001). Females had significantly higher concentrations of HCB and p, p'-DDE than males in the overall population sample. HCB concentrations were significantly higher in females than in males of Milan ( p = 0.029). We observed positive correlations of p, p'-DDE and HCB with age in Novafeltria subjects ( r = 0.468, p = 0.004). Total OCP concentrations differed significantly across BMI categories ( p = 0.018) in overall population. We have demonstrated a clear pattern of the main OCPs in a fairly large population. Generally, our study provides information on OCPs exposure among the Italian general population and provides indications for further investigations.

Quantitative analysis of organochlorine pesticides in human serum using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry

Persistent organochlorine pesticides (OCPs) are well known to accumulate in environment and to instigate disruptions in endocrine system. In the present study, 18 kinds of OCPs were bio-monitored from 1904 adult serums. Analysis was performed with headspace gas chromatography (HS-GC) which has the advantage to require small volume of serum (1mL) without complex pretreatment and (13)C isotope labeled internal standard mix was used for quantitation. As a result, eleven out of 18 OCPs, including hexachlorobenzene (HCB) and dichlorodiphenyltrichloroethane metabolites (DDTs) were detected. HCB was the most frequently detected OCP (8.0%) with an average concentration of 1.74ngg(-1) lipid (2.10ngg(-1) lipid-99.80ngg(-1) lipid). p,p'-Dichlorodiphenyldichloroethylene (p,p'-DDE) had the highest average concentration of 21.65ngg(-1) lipid (12.80ngg(-1) lipid-2270ngg(-1) lipid) and was detected from 7.5% of serum samples. The average concentration of ∑DDT metabolites was 32.04ngg(-1) lipid (6.61ngg(-1) lipid-2800ngg(-1) lipid) with detection frequency of 9.0%. Results interpreted with respect to age groups showed increase in ∑OCPs and ∑DDTs concentrations as age increases, except for the 20. Results interpreted with respect to gender, in general, illustrated higher detected concentration of OCPs in male serums than in female serums; however, the result trend was reversed in age group of the sixties. The above results will be applicable to health impact assessment of Koreans in relation to environmental contaminations.

Assessing exposure to polybrominated diphenyl ethers (PBDEs) for workers in the vicinity of a large recycling facility

Increased levels of polybrominated diphenyl ethers (PBDEs) can occur particularly in dust and soil surrounding facilities that recycle products containing PBDEs. This may be the source of increased exposure for nearby workers and residents. To investigate, we measured PBDE levels in soil, office dust and blood of workers at the closest workplace (i.e. within 100m) to a large automotive shredding and metal recycling facility in Brisbane, Australia. The workplace investigated in this study was independent of the automotive shredding facility and was one of approximately 50 businesses of varying types within a relatively large commercial/industrial area surrounding the recycling facility. Concentrations of PBDEs in soils were at least an order of magnitude greater than background levels in the area. Congener profiles were dominated by larger molecular weight congeners; in particular BDE-209. This reflected the profile in outdoor air samples previously collected at this site. Biomonitoring data from blood serum indicated no differential exposure for workers near the recycling facility compared to a reference group of office workers, also in Brisbane. Unlike air, indoor dust and soil sample profiles, serum samples from both worker groups were dominated by congeners BDE-47, BDE-153, BDE-99, BDE-100 and BDE-183 and was similar to the profile previously reported in the general Australian population. Estimated exposures for workers near the industrial point source suggested indoor workers had significantly higher exposure than outdoor workers due to their exposure to indoor dust rather than soil. However, no relationship was observed between blood PBDE levels and different roles and activity patterns of workers on-site. These comparisons of PBDE levels in serum provide additional insight into the inter-individual variability within Australia. Results also indicate congener patterns in the workplace environment did not match blood profiles of workers. This was attributed to the relatively high background exposures for the general Australian population via dietary intake and the home environment.

Concentration-dependent half-lives of polychlorinated biphenyl in sera from an occupational cohort

Polychlorinated biphenyls (PCBs) are carcinogenic. Estimating PCB half-life in the body based on levels in sera from exposed workers is complicated by the fact that occupational exposure to PCBs was to commercial PCB products (such as Aroclors 1242 and 1254) comprised of varying mixtures of PCB congeners. Half-lives were estimated using sera donated by 191 capacitor manufacturing plant workers in 1976 during PCB use (1946-1977), and post-exposure (1979, 1983, and 1988). Our aims were to: (1) determine the role of covariates such as gender on the half-life estimates, and (2) compare our results with other published half-life estimates based on exposed workers. All serum PCB levels were adjusted for PCB background levels. A linear spline model with a single knot was used to estimate two separate linear equations for the first two serum draws (Equation A) and the latter two (Equation B). Equation A gave half-life estimates of 1.74 years and 6.01 years for Aroclor 1242 and Aroclor 1254, respectively. Estimates were 21.83 years for Aroclor 1242 and 133.33 years for Aroclor 1254 using Equation B. High initial body burden was associated with rapid PCB elimination in workers at or shortly after the time they were occupationally exposed and slowed down considerably when the dose reached background PCB levels. These concentration-dependent half-life estimates had a transition point of 138.57 and 34.78 ppb for Aroclor 1242 and 1254, respectively. This result will help in understanding the toxicological and epidemiological impact of exposure to PCBs in humans.

Organochlorine compounds in bovine milk from the state of Mato Grosso do Sul-Brazil

Organochlorines are highly hydrophobic, synthetic organic pollutants that accumulate in the environment and in food webs. The primary route of human exposure to organochlorines is through food-mainly fat-rich food of animal origin such as meat, fish, and dairy products. Here we determined the presence and concentration of organochlorine residues in pasteurized milk from Mato Grosso do Sul, Brazil, to monitor consumer exposure to these contaminants. Organochlorine pesticides in milk samples were analyzed using solid phase extraction in octadecyl silica-prepacked columns and identified by gas chromatography using an electron capture detector. Of the 100 composite samples analyzed, more than 90% contained residues of organochlorine pesticides: aldrin was present in 44% of the samples, followed by ∑DDT (36%), mirex (34%), endosulfan (32%), chlordane (17%), dicofol (14%), heptachlor (11%) and dieldrin (11%). Compared to the values established by law, the concentration of the compounds in some samples was above the reference values. Given the importance that milk and its products have in the human diet, it is essential to know whether the levels of pesticide residues are kept well below the recommended levels to minimize the risk to human health.