Polybrominated diphenyl ethers, polychlorinated biphenyls, and organochlorine pesticides in adipose tissues of Korean women

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in adipose tissue of women from Grand Tunis and their association with demographic factors and dietary habits

Dichlorodiphenyl trichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and polychloronated biphenyls (PCBs) were measured in 25 woman adipose tissues collected in 2016 from Grand Tunis, Tunisia. p,p'-DDE, p,p'-DDT, HCB and β-HCH were the dominant organochlorine pesticides (OCPs) in decreasing order in all samples. The total OCP levels varied from 79 to 343 ng g-1 lipid with a median value of 189 ng g-1 lipid and DDTs contributed approximately 88% to sum OCP. The ratio of p,p'-DDT/p,p'-DDE across all samples is below one, which suggests mainly historic exposure but may indicate some recent exposure to the banned pesticide. The median concentration of PCBs was 109 ng g-1 lipid and ranged between 27 and 204 ng g-1 lipid. PCB-153, PCB-180, PCB-138 and PCB-170 were the most abundant congeners, which contributed about 78% of the total PCBs. Spearman analysis showed that dominant organochlorine compounds (OCs) are highly positive correlated except for PCB-28/31, indicating that women from Tunis are exposed via similar routes. Inhalation exposure could be a possible pathway for the uptake of the less chlorinated congeners. We found positive and statistically significant association with subjects age for HCB (r = 0.517; p = 0.009) and PCBs (r = 0.65; p = 0.001) levels and a weak age-dependent accumulation was found for HCHs (r = 0.375; p = 0.065) and DDTs (r = 0.388; p = 0.056). The concentrations of OC subgroups were not associated with BMI, parity and residence. No association was observed between fish, red/white meat, milk and dairy products consumption and levels of HCB, HCHs and PCBs. DDTs levels were significantly correlated only with milk (p = 0.048) and milk products (p = 0.047) intake.

A Dye-Assisted Paper-Based Assay to Rapidly Differentiate the Stress of Chlorophenols and Heavy Metals on Enterococcus faecalis and Escherichia coli

Biological toxicity testing plays an essential role in identifying the possible negative effects induced by substances such as organic pollutants or heavy metals. As an alternative to conventional methods of toxicity detection, paper-based analytical device (PAD) offers advantages in terms of convenience, quick results, environmental friendliness, and cost-effectiveness. However, detecting the toxicity of both organic pollutants and heavy metals is challenging for a PAD. Here, we show the evaluation of biotoxicity testing for chlorophenols (pentachlorophenol, 2,4-dichlorophenol, and 4-chlorophenol) and heavy metals (Cu²⁺, Zn²⁺, and Pb²⁺) by a resazurin-integrated PAD. The results were achieved by observing the colourimetric response of bacteria (Enterococcus faecalis and Escherichia coli) to resazurin reduction on the PAD. The toxicity responses of E. faecalis-PAD and E. coli-PAD to chlorophenols and heavy metals can be read within 10 min and 40 min, respectively. Compared to the traditional growth inhibition experiments for toxicity measuring which takes at least 3 h, the resazurin-integrated PAD can recognize toxicity differences between studied chlorophenols and between studied heavy metals within 40 min.

Associations between polybrominated diphenyl ethers (PBDEs) levels in adipose tissues and female menstrual cycle and menstrual bleeding duration in Shantou, China

The endocrine-disrupting effects of human exposure to polybrominated diphenyl ethers (PBDEs) have been studied, but their associations with menstrual status were not clearly clarified. This study was to evaluate the associations between PBDE levels in adipose tissues and the menstrual cycle and menstrual bleeding duration alteration. A total of 298 female cases undergoing surgery were recruited from two hospitals in Shantou, China. Demographic, clinical, and pathological information were collected, and adipose tissues were obtained during mammary or abdominal surgery. Gas chromatography with mass spectrometry was used to analyze 14 PBDE congeners in the adipose samples. The associations between PBDE levels and menstrual cycle (MC) and menstrual duration (MD) were analyzed by logistic regression models, estimating odds ratios (ORs) and 95% confidence intervals (CIs). BDE-153 had the highest level in the adipose samples, followed by BDE-209, BDE-183 and BDE-47. Compared with referents, median levels of BDE-47, -71, -153, -183 were higher in women with MC > 30 days (all P < 0.05); BDE-47, -153, -183, -209 were also higher in women with MD > 5.5 days (all P < 0.05). After adjusted for age and parity, BDE-47, -71, -153, -183 were associated with prolonged MC (OR = 1.20, 1.15, 1.12, 1.11, respectively, all P < 0.05) in the logistic regression models; and BDE-47, -153, -183, -209 were associated with the prolonged MD (OR = 1.13, 1.09, 1.10, 1.11, respectively, all P < 0.05). Several individual PBDE congeners in female adipose were found associated with prolonged menstrual cycle and menstrual duration. PBDEs may influence reproductive health of women by altering menstrual status.

First nationwide exposure profile of major persistent organic pollutants among Korean adults and their determinants: Korean National Environmental Health Survey Cycle 3 (2015-2017)

Since 2009, Korea has measured the exposure levels of major environmental chemicals and heavy metals among representative adult populations through the Korean National Environmental Health Survey (KoNEHS). However, exposure to persistent organic pollutants (POPs) has never been assessed. This study reports the serum concentrations of twenty-four POPs and their influencing factors for Korean adults (n = 1295) who participated in the KoNEHS Cycle 3 (2015-2017). The POPs included seven organochlorine pesticides (OCPs), eleven polychlorinated biphenyls (PCBs), and six polybrominated diphenyl ethers (PBDEs). Among them, three OCPs (i.e., hexachlorobenzene (HCB), p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE)) and five PCBs (i.e., PCB52, PCB118, PCB138, PCB153, and PCB180) were detected in over 60% of the samples. PBDEs were not detected at a detection frequency of 60% or above. The most frequently detected POPs were p,p'-DDE (99.8%, geometric mean of 128.47 ng/g lipid), followed by PCB180 (98.8%, 8.49 ng/g lipid), PCB153 (98.8%, 13.14 ng/g lipid), HCB (96.2%, 67.08 ng/g lipid), PCB138 (95.2%, 8.84 ng/g lipid), PCB118 (89.6%, 2.66 ng/g lipid), p,p'-DDT (80.5%, 6.68 ng/g lipid), and PCB52 (71.2%, 1.57 ng/g lipid). The concentrations of most POPs were lower than or similar to concentrations reported in national-scale biomonitoring surveys. The only exception was HCB, whose concentration was up to seven-fold higher than the concentration reported by the Canadian Health Measures Survey. Excluding HCB and PCB52, most POPs showed increasing serum levels among older adults, adults with higher body mass index, adults living in coastal areas, and more frequent fish consumption. Relatively higher POP concentrations were observed in menopausal women. This study provides the first data on POP exposure levels among the representative adult population in Korea, and the results highlight the need to integrate POPs in the national biomonitoring program.

Polybrominated diphenyl ethers quinone exhibits neurotoxicity by inducing DNA damage, cell cycle arrest, apoptosis and p53-driven adaptive response in microglia BV2 cells

Polybrominated diphenyl ethers (PBDEs) are world-wide used flame retardants before they were listed as Persistent Organic Pollutants (POPs) by the Stockholm Convention. Previously, our studies indicated that a quinone type of PBDE metabolite (PBDEQ) exposure was linked with neurotoxicity via excess free radical formation and oxidative stress. However, it is current unknown the effect of PBDEQ on genetic biomacromolecules DNA and corresponding biological consequences in neurological cells. Here, by employing phosphorylated histone H2AX in Serine 139 (γ-H2AX) and comet assay in microglia BV2 cells, our data suggested PBDEQ could triggered DNA damage. Furthermore, PBDEQ exposure led to the caspase 3-dependent cell apoptosis. Moreover, PBDEQ induced G2/M-phase cell arrest in a p53-dependent manner. Notably, p53 activation coordinated cell cycle progression, alleviated DNA damage and ultimately mitigated apoptosis in BV2 cells. Finally, antioxidant N-acetyl-l-cysteine (NAC) inhibited p53 activation upon PBDEQ exposure, and then ameliorated PBDEQ-induced DNA damage, cell cycle arrest and apoptosis, which illustrated that PBDEQ-induced DNA damage and p53 activation were mediated by reactive oxygen species (ROS). Together, the current findings unveil the fundamental toxicological mechanisms of PBDEQ, which propose a potential therapeutic strategy against the adverse effect caused by PBDE exposure.

Bioaccumulation of pesticide contaminants in tissue matrices of dogs suffering from malignant canine mammary tumors in Punjab, India

The unprecedented application of pesticides in Punjab, India during green revolution has lead to an environmental crisis due to the accumulation of persistent organic and pesticide pollutants in the environment and biota of this region. The present study aimed at estimating the abundance of pesticide contaminants in three biological matrices of 36 dogs suffering from malignant canine mammary tumor (mCMT) and 6 tumor free control dogs from Punjab, India. Presence of individual and total pesticides in canine biological samples, age and bodyweight of canine patients was assessed as a potential risk factor for mCMT using logistic regression analysis. Chi-square test was employed to determine tissue-specific accumulations of individual pesticides. Spearman's correlation coefficient was estimated to determine the association between the levels of total pesticides in different tissue matrices and with age and bodyweight of mCMT cases. Gas chromatography-ECD analysis of serum, mammary tissue and adjoining mammary adipose tissue revealed fourteen different pesticides including γ-HCH, α-HCH, dieldrin, aldrin, heptachlor, butachlor, p,p-DDT, o,p-DDT, p,p-DDD, p,p-DDE, L-cyhalothrin, permethrin, fipronil, and fenitrothion. Heptachlor, γ-HCH, aldrin and p,p-DDT were more frequently detected, whereas, p,p-DDE and o,p-DDT were the least common. Differential accumulation of pesticides in tissue matrices, particularly between serum and mammary tissue/adipose tissue was observed. We could not find any association between the total pesticide concentrations among serum, mammary tissue and mammary adipose tissue in mCMT cases. We found that the odds for individual pesticide for serum, mammary tissue and adipose tissue were associated with high uncertainties; however, the total pesticide concentration in mammary tissue was near non-significantly associated with higher risk of mCMT with low uncertainty. Statistically non-significant higher odds of CMT occurrence with increase in age was noticed No association between the concentration of total pesticides in different matrices and age and bodyweight of canine subjects was found.

Exposure pathways, levels and toxicity of polybrominated diphenyl ethers in humans: A review

Polybrominated diphenyl ethers (PBDEs) are extensively used as brominated flame retardants (BFRs) in different types of materials, which have been listed as Persistent Organic Pollutants (POPs) by the Stockholm Convention in 2009 and 2017. Due to their ubiquities in the environment and toxicities, PBDEs have posed great threat to both human health and ecosystems. The aim of this review is to offer a comprehensive understanding of the exposure pathways, levels and trends and associated health risks of PBDEs in human body in a global scale. We systematically reviewed and described the scientific data of PBDE researches worldwide from 2010 to March 2020, focusing on the following three areas: (1) sources and human external exposure pathways of PBDEs; (2) PBDE levels and trends in humans; (3) human data of PBDEs toxicity. Dietary intake and dust ingestion are dominant human exposure pathways. PBDEs were widely detected in human samples, especially in human serum and human milk. Data showed that PBDEs are generally declining in human samples worldwide as a result of their phasing out. Due to the common use of PBDEs, their levels in humans from the USA were generally higher than that in other countries. High concentrations of PBDEs have been detected in humans from PBDE production regions and e-waste recycling sites. BDE-47, -153 and -99 were proved to be the primary congeners in humans. Human toxicity data demonstrated that PBDEs have extensively endocrine disruption effects, developmental effects, and carcinogenic effects among different populations.

Intensive weight loss and cognition: The dynamics of persistent organic pollutants in adipose tissue can explain the unexpected results from the Action for Health in Diabetes (Look AHEAD) study

OBJECTIVE

The aim of this paper is to propose a new hypothesis for the role of lipophilic chemical mixtures stored in adipose tissue in the development of dementia. Specifically, we present how the dynamics of these chemicals can explain the unexpected findings from the Action for Health in Diabetes (Look AHEAD) study, which failed to show long-term benefits of intentional weight loss on cognition, despite substantial improvements in many known risk factors for dementia. Moreover, we discuss how the role of obesity in the risk of dementia can change depending on the dynamics of these chemicals in adipose tissue.

NEW HYPOTHESIS

Human adipose tissue is widely contaminated with various neurotoxic chemicals. Typical examples are persistent organic pollutants (POPs), strong lipophilic chemicals with long half-lives. Both unintentional and intentional weight loss increases the release of POPs from adipocytes into the circulation. As POPs in the blood can easily reach the brain, the intentional weight-loss group of the Look AHEAD study may have experienced an unappreciated and long-term disadvantage on their cognition. Additionally, POPs may be involved in the link between obesity and dementia, as dysfunctional hypertrophic adipocytes enhance the release of POPs from adipocytes to the circulation through uncontrolled lipolysis. In contrast, metabolically healthy obese people may have a low risk of dementia because the safe storage of POPs in adipose tissue would decrease the amount of POPs reaching the brain.

MAJOR CHALLENGES FOR THE HYPOTHESIS

In human studies, there are practical difficulties involved with measuring POPs in the blood, including high costs and complex assays. As the serum concentrations of POPs are continuously affected by weight loss and gain, prospective studies may require serial measurements of POPs. In in-vitro and in-vivo experimental studies, how to simulate the exposure dose, duration, and mixture patterns in humans would be critical.

LINKAGE TO OTHER MAJOR THEORIES

Even though POPs are direct neurotoxins at a high dosage, low-dose POPs are mitochondrial toxins. Therefore, chronic exposure to low-dose POPs is linked to known key interrelated mechanisms in the pathogenesis of dementia, such as mitochondrial dysfunction and neuroinflammation.

Multicenter biomonitoring of polybrominated diphenyl ethers (PBDEs) in colostrum from China: Body burden profile and risk assessment

Polybrominated diphenyl ethers (PBDEs) were listed in the Stockholm Convention due to their persistent and toxic nature. In utero exposure to PBDEs might affect fetal development as it is sensitive when exposed to even low dose of xenobiotic substances during the pregnancy. In this study, a multi-centre human biomonitoring study of tri-to hexa-BDEs was conducted in three Chinese cities using 60 colostrum samples from local residents. The patterns and influencing factors, correlation with the birth outcome, and potential health risks during the breastfeeding of tri-to hexa-BDEs in the colostrum samples were assessed. The median concentration of tri-to hexa-BDEs was 9.1 (Interquartile range: 3.1-19.5) ng g^-1 lipid weight, and BDE-153 contributed 68% of the detected PBDEs. The PBDE levels were mostly associated with maternal age and drinking water sources, while correlations with other factors including weight gain, BMI, parity and the number of aborted pregnancies was not significant. The level of BDE-28 was positively correlated with the birth weight, while the BDE-99 was positively correlated with the head circumference, using multilinear regression. For the total hazard quotients, 60% of the infants have an estimated value higher than 1, showed potential chronic hazard for future development and possible adverse health effects to the babies from the exposure to PBDE congeners. Alternative food source seems to have a lower risk for neonates than the colostrum, but the advantages of breastfeeding undoubtedly outweigh the risks and potential adverse health effects caused by environmental PBDEs and other xenobiotic chemical exposure.

Mobilization of Environmental Toxicants Following Bariatric Surgery

OBJECTIVE

Persistent organic pollutants (POPs) are lipophilic environmental toxicants that accumulate in adipose tissue. Weight loss leads to mobilization and increased redistribution of these toxicants. Many are obesogens and endocrine disruptors. Increased exposure could pose long-term health risks. The study objective was to measure the changes in serum concentrations of lipophilic POPs during significant weight loss.

METHODS

This study enrolled 27 patients at a university hospital in a longitudinal, 6-month, observational study examining changes in POP blood levels after bariatric surgery. The primary outcome was the changes in the concentrations of 24 polychlorinated biphenyls (PCBs), 9 organochlorine pesticides (OCPs), 11 polybrominated diphenyl ethers, 2,2',4,4',5,5'-hexabromobiphenyl, and 4 perfluorochemicals (PFCs).

RESULTS

Older adults (those born before 1976) had baseline levels of PCBs, OCPs, and PFCs that were two- to fivefold higher than younger adults (those born after 1976). Older adults had greater increases in PCBs, OCPs, and polybrominated diphenyl ethers associated with weight loss. Conversely, younger adults had greater increases in PFCs associated with weight loss. On average, blood POP levels increased as weight loss occurred.

CONCLUSIONS

Although weight loss is considered beneficial, the release and redistribution of POPs to other lipid-rich organs such as the brain, kidneys, and liver warrant further investigation. Interventions should be considered to limit organ exposure to POPs when weight loss interventions are planned.

Establishing a role for environmental toxicant exposure induced epigenetic remodeling in malignant transformation

Humans are exposed to a wide variety of environmental exposures throughout their lifespan. These include both naturally occurring toxins and chemical toxicants like pesticides, herbicides, and industrial chemicals, many of which have been implicated as possible contributors to human disease susceptibility [1-3]. We, and others, have hypothesized that environmental exposures may cause adaptive epigenetic changes in regenerative cell populations and developing organisms, leading to abnormal gene expression and increased disease susceptibility later in life [3]. Common epigenetic changes include changes in miRNA expression, covalent histone modifications, and methylation of DNA. Importantly, due to their heritable nature, abnormal epigenetic modifications which occur within stem cells may be particularly deleterious. Abnormal epigenetic changes in regenerative cell linages can be passed onto a large population of daughter cells and can persist for long periods of time. It is well established that an accumulation of epigenetic changes can lead to many human diseases including cancer [4-6]. Subsequently, it is imperative that we increase our understanding of how common environmental toxins and toxicants can induce epigenetic changes, particularly in stem cell populations. In this review, we will discuss how common environmental exposures in the United States and around the world may lead to epigenetic changes and discuss potential links to human disease, including cancer.

Distribution of Organohalogen and Synthetic Musk Compounds in Breast Adipose Tissue of Breast Cancer Patients in Ulster County, New York, USA

We determined the concentrations of 98 halogenated organic compounds and synthetic musks in breast fat tissues of 50 breast cancer patients (age range: 34-77 years) collected during 1996-1998 in Ulster County, New York, USA. Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated biphenyl 153 (PBB-153), polybrominated diphenyl ethers (PBDEs), and synthetic musk compounds (SMCs) were analyzed in breast fat tissues, and 46 analytes were found at a detection frequency of ≥ 65% and at concentrations in the decreasing order of OCPs > PCBs > SMCs > PBDEs > PBB-153. PCBs (median: 323 ng/g wet wt) and dichlorodiphenyltrichloroethanes (DDTs, median: 293 ng/g wet wt) were the major compounds found in breast fat tissues. Among PCB congeners, hexa- and hepta-chlorobiphenyls (60% of total PCBs) were the abundant ones. p,p'-DDE accounted for more than 99% of the total DDT concentrations. The concentrations of SMCs and PBDEs were 1-2 orders of magnitude lower than those of PCBs and DDTs. 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-r-2-benzopyran (median: 33 ng/g wet wt) was the most abundant SMC, whereas BDE-47 (median: 4.5 ng/g wet wt) was the most dominant PBDE congener present in breast tissues. A significant correlation (p < 0.05) between women's age and concentrations of DDTs, chlordanes, hexachlorobenzene and PCBs in breast tissues was found. Concentrations of PCBs, PBDEs, OCPs, and SMCs were not significantly different between malignant and benign tumor cases. This study adds baseline information on target tissue burdens of persistent organic contaminants in breast cancer patients.

The occurrence and dynamics of polychlorinated hydrocarbons in roe deer (Capreolus capreolus) in South-western Slovakia

The goal of this study was to determined polychlorinated biphenyls (PCBs) and organochlorine pesticides in the depot fat of roe deer (Capreolus capreolus) coming from south-western Slovakia. The mutual correlations of the organic pollutants were analyzed. The study included dichlorodiphenyltrichloroethane (DDT), hexachlorobenzen (HCB), alpha-hexachlorocyclohexane and beta-hexachlorocyclohexane (α + β-HCH), gamma-hexachlorocyclohexane (γ-HCH), and polychlorinated biphenyls (PCB-delor). The gas chromatograph with an electron capture detector ECD was used for analysis. The accumulations of organic pollutant in depot fat of roe deer were in following order: DDT > PCB-delor > α + β-HCH > HCB > γ-HCH. Among all pollutants, DDT was accumulated significantly in the highest level in the samples. The significantly higher content of DDT, HCB, α + β-HCH, and γ-HCH was detected in the adult animals when compared to the juveniles. Some strong positive correlations among pollutants, between HCB and DDT, α + β-HCH and HCB, α + β-HCH and HCB, between γ-HCH and other pollutants, and between PCB-delor and γ-HCH were found. Game animals are a part of human food chain and monitoring of the environment pollution by PCBs and other organic pollutants are worthy to study.

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.

Ecological and human exposure assessment to PBDEs in Adige River

The interest for environmental issues and the concern resulting from the potential exposure to contaminants were the starting point to develop methodologies in order to evaluate the consequences that those might have over both the environment and human health. Considering the feature of POPs, including PBDEs, such as bioaccumulation, biomagnification, long-range transport and adverse effects even long time after exposure, risk assessment of POPs requires specific approaches and tools. In this particular context, the MERLIN-Expo tool was used to assess the aquatic environmental exposure of Adige River to PBDEs and the accumulation of PBDEs in humans through the consumption of possible contaminated local aquatic food. The aquatic food web models provided as output of the deterministic simulation the time trend of concentrations for twenty years of BDE-47 and total PBDEs, expressed using the physico-chemical properties of BDE-47, in aquatic organisms of the food web of Adige River. For BDE-47, the highest accumulated concentrations were detected for two benthic species: Thymallus thymallus and Squalius cephalus whereas the lowest concentrations were obtained for the pelagic specie Salmo trutta marmoratus. The trend obtained for the total PBDEs, calculated using the physico-chemical properties of BDE-47, follows the one of BDE-47. For human exposure, different BDE-47 and total PBDEs concentration trends between children, adolescent, adults and elderly were observed, probably correlated with the human intake of fish products in the daily diet and the ability to metabolize these contaminants. In detail, for the adolescents, adults and elderly a continuous accumulation of the target contaminants during the simulation's years was observed, whereas for children a plateau at the end of the simulation period was perceived.

A role of low dose chemical mixtures in adipose tissue in carcinogenesis

The Halifax project recently hypothesized a composite carcinogenic potential of the mixture of low dose chemicals which are commonly encountered environmentally, yet which are not classified as human carcinogens. A long neglected but important fact is that adipose tissue is an important exposure source for chemical mixtures. In fact, findings from human studies based on several persistent organic pollutants in general populations with only background exposure should be interpreted from the viewpoint of chemical mixtures because serum concentrations of these chemicals can be seen as surrogates for chemical mixtures in adipose tissue. Furthermore, in conditions such as obesity with dysfunctional adipocytes or weight loss in which lipolysis is increased, the amount of the chemical mixture released from adipose tissue to circulation is increased. Thus, both obesity and weight loss can enhance the chance of chemical mixtures reaching critical organs, however paradoxical this idea may be when fat mass is the only factor considered. The complicated, interrelated dynamics of adipocytes and chemical mixtures can explain puzzling findings related to body weight among cancer patients, including the obesity paradox. The contamination of fat in human diet with chemical mixtures, occurring for reasons similar to contamination of human adipose tissue, may be a missing factor which affects the association between dietary fat intake and cancer. The presence of chemical mixtures in adipose tissue should be considered in future cancer research, including clinical trials on weight management among cancer survivors.

Organochlorine pesticides and polychlorinated biphenyls in human adipose tissue from northern Tunisia: Current extent of contamination and contributions of socio-demographic characteristics and dietary habits

The aims of the present study were to investigate the current exposure levels of persistent organochlorine compounds (OCs) in adipose tissues intraoperatively collected from 40 patients over 20 years undergoing non-cancer-related surgery residing in Northern region of Tunisia (Bizerte), which constitutes an exemplary case, and examined association between levels of contamination and both socio-demographic characteristics and dietary habits. Concentration of hexachlorobenzene (HCB), hexachlorocyclohexane isomers (α-HCH, β-HCH, γ-HCH and δ-HCH), dichlorodiphenyltrichloroethane isomers (p,p'-DDT and o,p'-DDT) and metabolites (p,p'-DDE, o,p'-DDE, p,p'-DDD and o,p'-DDD) and 12 polychlorinated biphenyls (PCBs) congeners were measured using capillary gas chromatography with electron capture detector. Overall, residue levels of OCs followed the decreasing order of DDTs > PCBs > HCB > HCHs. DDTs levels ranged from 74.49 to 1834.76ngg^-1 lipid and contributing to more than 90% to the sum of organochlorine pesticides (OCPs). p,p'-DDE was the most abundant in all samples and the p,p'-DDT/p,p'-DDE ratio (range between 1.85% and 58.45%) suggesting recent and ongoing exposure to banned commercial DDT products. PCB concentrations varied from 29.27 to 322.58ngg^-1 lipid and PCB-180, PCB-153 and PCB-138 were the dominant congeners accounting for 70% of total PCBs. We did not find significant correlations between OC exposure levels and sex, parity, habitat areas and smoking habits. In females, the adipose tissue concentrations of DDTs, HCB and PCB-118 were positively correlated with age. There was statistically significant relationship between body mass index (BMI) changes and the adipose tissue levels of HCB and HCHs. No association was found between OCPs levels and dietary factors. However, our study suggests that fish consumption may be an important contributor of PCBs adipose tissue content of PCBs in Tunisian people. The presented work is highly significant, being the first study pointing out the chronic exposure to OCs in Bizerte.

Recent strategies for removal and degradation of persistent & toxic organochlorine pesticides using nanoparticles: A review

Organochlorines (OCs) are the most hazardous class of pesticides, therefore, banned or restricted in several countries. The major sources of OCs include food industries, agriculture and sewage wastes. Their effluents discharged into the water bodies contain extremely high concentration of OCs which ultimately causes environmental concern. Because of their high persistence, toxicity and potential to bioaccumulation, their removal from wastewater is imperative. The degradation techniques are now advanced using nanomaterials of various kinds. During the last few years, nanoparticles such as TiO₂ and Fe are found to be excellent adsorbents and efficient photocatalysts for degrading more or less whole OCs as well as their toxic metabolites, which opens the opportunities for exploring various other nanoparticles as well. It is noteworthy that such methodologies are economic, fast and very efficient. In this review, the detailed information on different types of OC pesticides, their metabolites, environmental concern and present status on degradation methods using nanoparticles have been reviewed. An attempt has also been made to highlight the research gaps prevailing in the current research area.

Spatial distribution and source identification of indicator polychlorinated biphenyls in soil collected from the coastal multi-industrial city of Ulsan, South Korea for three consecutive years

The concentrations, profiles, and source-receptor relationships of seven indicator polychlorinated biphenyls (PCBs) (#28, 52, 101, 118, 138, 153, and 180) found in soil at 25 rural, urban, and industrial sites in Ulsan, South Korea were investigated. For this study, 75 soil samples were collected, 25 each in January of 2011, 2012, and 2013. Principal component analysis was used to evaluate the influence of the emission sources on the soil samples. The concentrations of total seven PCBs (Σ7 PCBs) ranged between 0.034 ng/g and 143 ng/g (mean: 5.10 ng/g, median: 0.440 ng/g), which indicated slight or moderate contamination levels, respectively, compared to those in the other countries or other cities in Korea. The concentrations of Σ7 PCBs at the industrial and urban sites were significantly higher than those at the rural sites, due to the direct influence of emission sources related to industrial activities rather than urban emission sources. Generally, the profiles of PCBs were dominated by penta- and hexa-chlorinated biphenyls at all the study sites, suggesting common sources of PCBs in Ulsan. PCB source identification indicated that leakage from transformer oils in the major industrial complexes and PCB-containing paints used in the automobile and shipbuilding industrial complexes were possibly the main sources of indicator PCBs in the study areas.

Levels and Profiles of Polybrominated Diphenyl Ethers in Breast Milk During Different Nursing Durations

Eight PBDE congeners, BDE-28, 47, 99, 100, 153, 154, 183 and 209, were measured using gas chromatography coupled to mass spectrometry. The concentrations of Σ8PBDEs ranged from 0.04 to 19.93 ng g(-1) lipid weight (lw), with median and mean value of 1.21 and 2.72 ng g(-1) lw. PBDE congeners were detected in approximately 90 % of samples with BDE-209 as the dominant one. No significant correlations were found between the mothers' age, body mass index and PBDEs concentrations. We estimated the infant's dietary intake of the studied PBDEs via human milk during different nursing durations, and found that babies younger than 1 month might take a relatively higher body burden of PBDEs. The median levels of Σ8PBDEs were 0.74, 2.80, 2.43 and 0.90 ng g(-1) lw in colostrum, milk sampled at 1, 3 and 6 months after birth, respectively. High consumption of animal-origin food after birth may lead to the elevated ΣPBDEs concentrations in breast milk. A rational nutrition deployment is essential for postpartum mother.

Characterizing distributions, composition profiles, sources and potential health risk of polybrominated diphenyl ethers (PBDEs) in the coastal sediments from East China Sea

Sediment samples (n = 20) were collected from Yangtze River Estuary (YRE) and the adjacent East China Sea (ECS) inner shelf to explore spatial and temporal distributions, environmental fate, sources and potential health risk of polybrominated diphenyl ethers (PBDEs). Concentrations of BDE-209 and total 7 PBDEs (without BDE-209; ∑7PBDEs) ranged from 62.3 to 1758 pg g(-1) and from 36.9 to 233.6 pg g(-1) dry weight, respectively; both of the highest values occurred near the city of Wenzhou. Concentrations of BDE-209 and ∑7PBDEs both indicated a decreasing trend from inshore areas toward outer shelf. Significantly positive linear correlations were only observed between logBDE-183 concentrations and TOC/grain size (r(2) = 0.6734 and 0.5977 for TOC and grain size, respectively) as well as BDE-209 and TOC/grain size (r(2) = 0.4137 and 0.5332 for TOC and grain size, respectively) in the north of 28(°)N, indicating that YR had significant influence on the distribution of higher brominated congeners only in the north part. Depth profiles of PBDEs in a sediment core P01 (n = 1, m = 11) collected from YRE showed that the input of BDE-209 gradually increased from 1930 to 2010, while the levels of ∑7PBDEs peaked in 1986 and obviously decreased in recent years. Partial Least-Squares Regression (PLSR) revealed that PBDEs in the coastal ECS were mainly from direct discharge of local anthropogenic activities (80.7%), followed by surface runoff of contaminated soils (15.1%), microbial degradation after sedimentation (2.6%) and photodegradation during atmospheric transportation (1.6%). The cancer risk of human exposure to BDE-209 at the 95% confidence level was 3.09 × 10(-7), 1.67 × 10(-7) and 8.86 × 10(-7) for children, teens and adults, respectively, significantly lower than the threshold level (10(-6)). Hazard index (HI) calculated for non-cancer risk was also far less than 1 for the three groups, suggesting no non-cancer risk.

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.

Association between prenatal exposure to polybrominated diphenyl ethers and young children's neurodevelopment in China

The use of polybrominated diphenyl ethers (PBDEs) has been dramatically increasing over the last two decades in China. Animal studies suggest that prenatal exposure to PBDEs may result in neurodevelopmental deficits. Two hundred thirty-two participating mothers were recruited from a prospective birth cohort in rural northern China between September 2010 and February 2012. We analyzed 232 cord blood specimens for selected PBDE congeners and examined their association with children's developmental quotients (DQs) at 12 (n=192) and 24 (n=149) months of age based on the Gesell Developmental Schedules (motor, adaptive, language, and social domains). There were no substantial differences by demographic characteristics among the three time points: baseline, 12 and 24 months of age. Median cord blood levels of PBDE congeners 47, 99, 100, and 153 were 3.71, 6.70, 2.63, and 2.19 ng/g lipid, respectively. At 12 months of age, neither the individual nor total (the sum of BDEs 47, 99, 100, and 153) congener levels were associated with any of the four domain DQs. However, at 24 months of age, a 10-fold increase in BDE-99 levels was associated with a 2.16-point decrease [95% confidence interval (CI): -4.52, -0.20] in language domain DQs and a 10-fold increase in BDE-47 levels was associated with a 1.89-point decrease (95% CI: -3.75, -0.03) in social domain DQs. Prenatal exposure to PBDEs was associated with lower DQs in young children. The results contribute to the growing evidence that PBDEs could act as developmental neurotoxicants,and the findings have implications for children's environmental health in China.

Human exposure to PBDE and critical evaluation of health hazards

Polybrominated diphenyl ethers (PBDEs) are used in large quantities as flame-retardant additives in a number of commercial products. Biomonitoring data show that, in recent years, PBDE concentrations have increased rapidly in the bodies of wildlife and humans. Usually, PBDE levels in North America have been reported to be higher than those in Europe and Asia. Moreover, body burden of PBDEs is three- to ninefold higher in infants and toddlers than in adults, showing these last two age groups the highest levels of these compounds, due to exposure via maternal milk and through dust. Tetra-, Penta-, and Hexa-BDEs are the isomers most commonly found in humans. Based on studies on experimental animals, the toxicological endpoints of exposure to PBDEs are likely to be thyroid homeostasis disruption, neurodevelopmental deficits, reproductive changes, and even cancer. Experimental studies in animals and epidemiological observations in humans suggest that PBDEs may be developmental neurotoxicants. Pre- and/or postnatal exposure to PBDEs may cause long-lasting behavioral abnormalities, particularly on motor activity and cognition. This paper is focused on reviewing the current status of PBDEs in the environment, as well as the critical adverse health effects based on the recent studies on the toxic effects of PBDEs.

Polybrominated diphenyl ethers (PBDEs) in the indoor dust in China: levels, spatial distribution and human exposure

Indoor environment is an important source of human exposure to several toxicants, such as brominated flame retardants. Indoor dust samples were collected in winter season in 2010, which covered 23 provinces across China, for the analysis of polybrominated diphenyl ethers (PBDEs). Concentrations of PBDEs (Σ14PBDEs) ranged from 8.92 to 37,500 ng/g, with the mean of 3520 ng/g. BDE-209 was the most dominate congener, followed by BDE-183, BDE-47 and BDE-99. PBDE concentrations and the longitude were significantly correlated (p<0.05), which was consistent with the status of social-economic development and human activities. The results of exposure to PBDEs through dust ingestion and dermal absorption indicated that the toddlers had the highest exposure dose, with the median value of 6.0 ng/kg-bw/day. According to the hazard quotients, health risk of PBDEs via dust ingestion in China is currently acceptable. Monte Carlo simulation was implemented to quantify the uncertainty and sensitivity of exposure models for determining the most influential variables. The results suggested that more specific and accurate parameters should be used for dust ingestion and dermal absorption exposure models in future.

PCB-153 shows different dynamics of mobilisation from differentiated rat adipocytes during lipolysis in comparison with PCB-28 and PCB-118

Background

Polychlorinated biphenyls (PCBs) are persistent organic pollutants. Due to their lipophilic character, they are preferentially stored within the adipose tissue. During the mobilisation of lipids, PCBs might be released from adipocytes into the bloodstream. However, the mechanisms associated with the release of PCBs have been poorly studied. Several in vivo studies followed their dynamics of release but the complexity of the in vivo situation, which is characterised by a large range of pollutants, does not allow understanding precisely the behaviour of individual congeners. The present in vitro experiment studied the impact of (i) the number and position of chlorine atoms of PCBs on their release from adipocytes and (ii) the presence of other PCB congeners on the mobilisation rate of such molecules.

Methodology/Principal Findings

Differentiated rat adipocytes were used to compare the behaviour of PCB-28, -118 and -153. Cells were contaminated with the three congeners, alone or in cocktail, and a lipolysis was then induced with isoproterenol during 12 hours. Our data indicate that the three congeners were efficiently released from adipocytes and accumulated in the medium during the lipolysis. Interestingly, for a same level of cell lipids, PCB-153, a hexa-CB with two chlorine atoms in ortho-position, was mobilised slower than PCB-28, a tri-CB, and PCB-118, a penta-CB, which are both characterised by one chlorine atom in ortho-position. It suggests an impact of the chemical properties of pollutants on their mobilisation during periods of negative energy balance. Moreover, the mobilisation of PCB congeners, taken individually, did not seem to be influenced by the presence of other congeners within adipocytes.

Conclusion/Significance

These results not only highlight the obvious mobilisation of PCBs from adipocytes during lipolysis, in parallel to lipids, but also demonstrate that the structure of congeners defines their rate of release from adipocytes.

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.

Organochlorine pesticide level differences among female inhabitants from Veracruz, Puebla and Tabasco, Mexico

Organochlorine pesticides have been used in Mexico in malaria control programs and against ectoparasites. The objective of this study was to compare the levels of organochlorine pesticides: HCB, α-β-γ-HCH, pp'-DDE, op'-DDT and pp'-DDT in adipose tissue of female inhabitants from three Mexican states: Veracruz, Puebla and Tabasco. Data analyses indicated higher β-HCH levels in Puebla inhabitants. When comparing the mean values of the pp'-DDE concentrations among the three states, no statistically significant differences were noted. A trend of increasing concentrations of op'-DDT from Veracruz to Puebla and Tabasco was observed. Significantly higher pp'-DDT concentrations in Veracruz as compared to Puebla and Tabasco were determined. Using factorial analysis of three age categories (>30, 31-50, <51) organochlorine pesticide concentrations increases with age of participants, indicating time of exposure as a principal factor of organochlorine pesticides accumulation in adipose tissue.

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.

Simultaneous determination of polybrominated diphenyl ethers and polychlorinated biphenyls by gas chromatography-tandem mass spectrometry in human serum and plasma

Sensitive and reliable methods for simultaneous determination of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in limited volumes of human serum or plasma need to be further documented especially when they accumulate at low levels that are still capable of disrupting endocrine and immune functions, and affecting neurodevelopment and reproduction. The objective of this study was to develop and validate a sensitive and quantitative method that simultaneously quantifies PBDEs and PCBs in 0.5 ml of human serum or plasma. We optimized a solid-phase extraction (SPE) method and used silica particle purification for the extraction of PBDEs and PCBs. Two multiple reactions monitoring (MRM) transitions were optimized for each congener. The sum of the transitions was used for quantification, and their abundance ratios were used for identification. The combined method optimization techniques resulted in limits of detection from 3 to 145 pg/ml for 10 PBDEs and 1-12 pg/ml for 15 PCBs. Method was solidly validated by analyzing serum fortified with a certified PBDE and PCB standard mixture from the National Institute of Standards and Technology (NIST). The accuracy was 88-118% and day-to-day precision was within 19%. The method was successfully applied to quantify native concentrations of PBDE and PCB in commercially available human serum. The sensitivity and selectivity of the GC/EI-MS/MS analysis enables it to be the method of choice for investigations of exposures to PBDE and PCB congeners, especially when sample volume is limited.

Distribution of persistent organic pollutants in two different fat compartments from obese individuals

There are only few studies defining persistent organic pollutant (POP) concentrations in various fat compartments from living obese individuals. The present study has therefore determined the concentrations of various classes of organohalogenated compounds, such as dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in visceral fat (VF: n=52) and subcutaneous abdominal fat (SF: n=52) samples collected in 2010-2012 from obese individuals in Belgium. Organohalogen compounds were detected in all fat samples in the decreasing order of their concentrations: PCBs>DDTs>HCHs>CHLs>HCB>HBCDs>PBDEs, suggesting that Belgians have been widely exposed to these contaminants. The levels and the patterns of POP distribution in VF and SF tissue depots were not significantly different. Concentrations of PCBs (VF/SF; median: 285/275ng/g lw) and DDTs (VF/SF; median: 150/155ng/g lw) were the major POPs in all fat samples. Concerning PCBs, PCB 153 (VF/SF: 27/26%) was the most dominant congener, followed by PCB 180 (VF/SF: 17/18%), PCB 138 (VF/SF: 15/14.5%) and PCB 170 (VF/SF: 8.1/8.4%) to the sum PCBs, respectively. Levels of HBCDs (VF/SF; median: 4.0/3.7ng/g lw) and PBDEs (VF/SF; median: 2.6/2.7ng/g lw) were 1-2 orders of magnitude lower than those of PCBs and DDTs. Among PBDEs, BDE 153 (VF/SF: 31/34%) was the dominant congener, followed by BDE 47 (VF/SF: 26/23%), BDE 154 (VF/SF: 16/16%), BDE 100 (VF/SF: 10/11%) and BDE 99 (VF/SF: 9/9%). To our knowledge, this is the first report on HBCD concentrations in Belgian human fat tissues. Total PBDE and HBCD levels in human fat samples could not be correlated with age. In agreement with the literature, a significant correlation (p<0.05) between age and the concentration of PCBs (r=0.828), DDTs (r=0.640), HCHs (r=0.666), CHLs (r=0.534) and HCB (r=0.754), was observed in the present study. Levels of DDTs, HCHs, HCB and CHLs were also significantly correlated to each other, suggesting that they share similar exposure routes. Correlation with computed tomography (CT) scan data revealed that VF and VF/SF ratios are positive for most of the POPs, such as PCBs, PBDEs, p,p'DDE, CHLs, β-HCH, and HCB. To our knowledge, this study is the first to assess the relationship between POP levels in adipose tissue and markers of abdominal adiposity, determined by CT.

Distribution of polybrominated diphenyl ethers in Japanese autopsy tissue and body fluid samples

Brominated flame retardants are components of many plastics and are used in products such as cars, textiles, televisions, and personal computers. Human exposure to polybrominated diphenyl ether (PBDE) flame retardants has increased exponentially during the last three decades. Our objective was to measure the body burden and distribution of PBDEs and to determine the concentrations of the predominant PBDE congeners in samples of liver, bile, adipose tissue, and blood obtained from Japanese autopsy cases. Tissues and body fluids obtained from 20 autopsy cases were analyzed. The levels of 25 PBDE congeners, ranging from tri- to hexa-BDEs, were assessed. The geometric means of the sum of the concentrations of PBDE congeners having detection frequencies >50 % (ΣPBDE) in the blood, liver, bile, and adipose tissue were 2.4, 2.6, 1.4, and 4.3 ng/g lipid, respectively. The most abundant congeners were BDE-47 and BDE-153, followed by BDE-100, BDE-99, and BDE-28+33. These concentrations of PBDE congeners were similar to other reports of human exposure in Japan but were notably lower than concentrations than those reported in the USA. Significant positive correlations were observed between the concentrations of predominant congeners and ΣPBDE among the samples analyzed. The ΣPBDE concentration was highest in the adipose tissue, but PBDEs were distributed widely among the tissues and body fluids analyzed. The PBDE levels observed in the present study are similar to those reported in previous studies in Japan and significantly lower than those reported in the USA.

The occurrence and dynamics of polychlorinated hydrocarbons in brown hare (Lepus europaeus) in south-western Slovakia

This study aimed at obtaining the data on the occurrence, levels and correlations of organic pollutants present in game animals (n = 75, Brown hare, Lepus europaeus Pall.) in the region of south-western Slovakia. The analyses performed included dichlorodiphenyltrichloroethane (DDT), hexachlorobenzen (HCB), alpha- and beta hexachlorocyclohexane (α+β-HCH), gamma-hexachlorocyclohexane (γ-HCH), and polychlorinated biphenyls (PCB-delor, commercial mixture of PCB congeners). A gas chromatograph with an electron capture detector was used for the analysis. PCB-delor and DDT were accumulated significantly in the highest level (0.105 ± 0.059 mg/kg; 0.070 mg/kg) in depot fat in brown hares; however maximum permissible limits for the observed pollutants were not exceeded. Significantly higher concentrations of DDT, HCB, γ-HCH, and PCB-delor were found in adult animals when compared with juvenile hares. Gender and season had no effect on the accumulation of observed pollutants. Moderately positive correlation was found between PCB-delor and DDT (r = 0.59). Monitoring of environmental pollution with polychlorinated hydrocarbons is important with regard to public health, as game animals constitute an important part of food chain also for humans.