Biological effects related to exposure to polychlorinated biphenyl (PCB) and decabromodiphenyl ether (BDE-209) on cats.

As an animal familiar to humans, cats are considered to be sensitive to chemicals; cats may be exposed to polychlorinated biphenyls (PCBs) and decabromodiphenyl ether (BDE-209) from indoor dust, household products, and common pet food, leading to adverse endocrine effects, such as thyroid hormone dysfunction. To elucidate the general biological effects resulting from exposure of cats to PCBs and PBDEs, cats were treated with a single i.p. dose of a principal mixture of 12 PCBs and observed for a short-term period. Results revealed that the testis weight, serum albumin, and total protein of the treated group decrease statistically in comparison with those in the control group. The negative correlations suggested that the decrease in the total protein and albumin levels may be disturbed by 4'OH-CB18, 3'OH-CB28 and 3OH-CB101. Meanwhile, the serum albumin level and relative brain weight decreased significantly for cats subjected to 1-year continuous oral administration of BDE-209 in comparison to those of control cats. In addition, the subcutaneous fat as well as serum high-density lipoprotein (HDL) and triglycerides (TG) levels increased in cats treated with BDE-209 and down-regulation of stearoyl-CoA desaturase mRNA expression in the liver occurred. These results suggested that chronic BDE-209 treatment may restrain lipolysis in the liver, which is associated with lipogenesis in the subcutaneous fat. Evidence of liver and kidney cell damage was not observed as there was no significant difference in the liver enzymes, blood urea nitrogen and creatinine levels between the two groups of both experiments. To the best of our knowledge, this is the first study that provides information on the biochemical effects of organohalogen compounds in cats. Further investigations on risk assessment and other potential health effects of PCBs and PBDEs on the reproductive system, brain, and lipid metabolism in cats are required.

Estrogenic, androgenic, and glucocorticoid activities and major causative compounds in river waters from three Asian countries.

Estrogen, androgen, and glucocorticoid receptors (ER, AR, and GR) agonist activities in river water samples from Chennai and Bangalore (India), Jakarta (Indonesia), and Hanoi (Vietnam) were evaluated using a panel of chemical-activated luciferase gene expression (CALUX) assays and were detected mainly in the dissolved phase. The ER agonist activity levels were 0.011-55 ng estradiol (E2)-equivalent/l, higher than the proposed effect-based trigger (EBT) value of 0.5 ng/l in most of the samples. The AR agonist activity levels were < 2.1-110 ng dihydrotestosterone (DHT)-equivalent/l, and all levels above the limit of quantification exceeded the EBT value of 3.4 ng/l. GR agonist activities were detected in only Bangalore and Hanoi samples at dexamethasone (Dex)-equivalent levels of < 16-150 ng/l and exceeded the EBT value of 100 ng/l in only two Bangalore samples. Major compounds contributing to the ER, AR, and GR agonist activities were identified for water samples from Bangalore and Hanoi, which had substantially higher activities in all assays, by using a combination of fractionation, CALUX measurement, and non-target and target chemical analysis. The results for pooled samples showed that the major ER agonists were the endogenous estrogens E2 and estriol, and the major GR agonists were the synthetic glucocorticoids Dex and clobetasol propionate. The only AR agonist identified in major androgenic water extract fractions was DHT, but several unidentified compounds with the same molecular formulae as endogenous androgens were also found.

Antiandrogenic and Estrogenic Activity Evaluation of Oxygenated and Nitrated Polycyclic Aromatic Hydrocarbons Using Chemically Activated Luciferase Expression Assays.

To establish the risk of the endocrine disrupting activity of polycyclic aromatic compounds, especially oxygenated and nitrated polycyclic aromatic hydrocarbons (oxy-PAHs and nitro-PAHs, respectively), antiandrogenic and estrogenic activities were determined using chemically activated luciferase expression (CALUX) assays with human osteoblast sarcoma cells. A total of 27 compounds including 9 oxy-PAHs (polycyclic aromatic ketones and quinones) and 8 nitro-PAHs was studied. The oxy-PAHs of 7H-benz[de]anthracen-7-one (BAO), 11H-benzo[a]fluoren-11-one (B[a]FO), 11H-benzo[b]fluoren-11-one (B[b]FO), and phenanthrenequinone (PhQ) exhibited significantly the potent inhibition of AR activation. All nitro-PAHs exhibited high antiandrogenic activities (especially high for 3-nitrofluoranthene (3-NFA) and 3-nitro-7H-benz[de]anthracen-7-one (3-NBAO)), and the AR inhibition was confirmed as noncompetitive for 3-NFA, 3-NBAO, and 1,3-dinitropyrene (1,3-DNPy). Antiandrogenic activity of 3-NFA demonstrated characteristically a U-shaped dose-response curve; however, the absence of fluorescence effect on the activity was confirmed. The prominent estrogenic activity dependent on dose-response curve was confirmed for 2 oxy-PAHs (i.e., B[a]FO and B[b]FO). Elucidating the role of AR and ER on the effects of polycyclic aromatic compounds (e.g., oxy- and nitro-PAHs) to endocrine dysfunctions in mammals and aquatic organisms remains a challenge.

Microplastics in dumping site soils from six Asian countries as a source of plastic additives.

The ubiquitous distribution of microplastics (MP) is a serious environmental issue in Asian countries. In this study, 54 open-dumping site soils collected from Cambodia, India, Indonesia, Laos, the Philippines, and Vietnam were analyzed for MP. Soil samples were also divided into light (floating) and heavy (sedimentation) fractions by density separation and analyzed for plastic additives. The highest abundance of MP was found in a soil from Cambodia at 218,182 pieces/kg. The median of MP in soils ranged from 1411 pieces/kg in India to 24,000 pieces/kg in the Philippines, suggesting that dumping sites are a major source of MP into the environment. Polyethylene, polypropylene, and polyethylene terephthalate were dominant polymers in soil samples analyzed. This indicates that daily-used plastic products are main sources of MP in dumping site soils in Asian countries. The high concentrations and burdens of phthalates and an antioxidant were detected in floating fraction accounting for 40 to 60% of the total additives in soils. Previous studies on soil pollution have assumed that the organic hydrophobic chemicals analyzed are adsorbed on the surface of soil particles. However, this result indicates that approximately half of the additives in dumping site soils were derived from MP, not soil particle. Monitoring study on soil pollution should be considered the occurrence of MP in the matrices.

Polycyclic aromatic hydrocarbons in airborne particulate matter samples from Hanoi, Vietnam: Particle size distribution, aryl hydrocarbon ligand receptor activity, and implication for cancer risk assessment.

Concentrations and profiles of unsubstituted and methylated polycyclic aromatic hydrocarbons (PAHs and Me-PAHs) were analyzed in airborne particulate matter (PM) samples collected from high-traffic roads in Hanoi urban area. Levels of PAHs and Me-PAHs ranged from 210 to 660 (average 420) ng/m3 in total PM, and these pollutants were mainly associated with fine particles (PM2.5) rather than coarser ones (PM > 10 and PM10). Proportions of high-molecular-weight compounds (i.e., 5- and 6-ring) increased with decreasing particle size. Benzo[b+k]fluoranthene, indeno[1,2,3-cd]pyrene, and benzo[ghi]perylene were the most predominant compounds in the PM2.5 samples. In all the samples, Me-PAHs were less abundant than unsubstituted PAHs. The PAH-CALUX assays were applied to evaluate aryl hydrocarbon receptor (AhR) ligand activities in crude extracts and different fractions from the PM samples. Benzo[a]pyrene equivalents (BaP-EQs) derived by the PAH-CALUX assays for low polar fractions (mainly PAHs and Me-PAHs) ranged from 300 to 840 ng/m3, which were more consistent with theoretical values derived by using PAH-CALUX relative potencies (270-710 ng/m3) rather than conventional toxic equivalency factor-based values (22-69 ng/m3). Concentrations of PAHs and Me-PAHs highly correlated with bioassay-derived BaP-EQs. AhR-mediated activities of more polar compounds and interaction effects between PAH-related compounds were observed. By using PAH-CALUX BaP-EQs, the ILCR values ranged from 1.0 × 10-4 to 2.8 × 10-4 for adults and from 6.4 × 10-5 to 1.8 × 10-4 for children. Underestimation of cancer risk can be eliminated by using effect-directed method (e.g., PAH-CALUX) rather than chemical-specific approach.

Altered hepatic cytochrome P450 expression in cats after chronic exposure to decabromodiphenyl ether (BDE-209).

The knowledge of cytochrome P450 (CYP) expression involved in chemical exposure are necessary in clinical applications for the medication and prediction of adverse effects. The aim of this study was to evaluate the mRNA expression of CYP1-CYP3 families in cats exposed to BDE-209 for one year. All selected CYP isoforms showed no significant difference in mRNA expressions between control and exposure groups, however, CYP3A12 and CYP3A131 revealed tend to be two times higher in the exposure group compared to control group. The present results indicate that the chronic exposure of BDE209 could not alter CYP expression in the liver of cats. This result considered caused by the deficiency of CYP2B subfamily which is major metabolism enzyme of polybrominated diphenyl ethers (PBDEs) in cat.

Soil and sediment contamination by unsubstituted and methylated polycyclic aromatic hydrocarbons in an informal e-waste recycling area, northern Vietnam: Occurrence, source apportionment, and risk assessment.

Improper processing activities of e-waste are potential sources of polycylic aromatic hydrocarbons (PAHs) and their derivatives, however, information about the environmental occurrence and adverse impacts of these toxic substances is still limited for informal e-waste recycling areas in Vietnam and Southeast Asia. In this study, unsubstituted and methylated PAHs were determined in surface soil and river sediment samples collected from a rural village with informal e-waste recycling activities in northern Vietnam. Total levels of PAHs and MePAHs decreased in the order: workshop soil (median 2900; range 870-42,000 ng g-1) > open burning soil (2400; 840-4200 ng g-1) > paddy field soil (1200; range 530-6700 ng g-1) > river sediment samples (750; 370-2500 ng g-1). About 60% of the soil samples examined in this study were heavily contaminated with PAHs. Fingerprint profiles of PAHs and MePAHs in the soil and sediment samples indicated that these pollutants were mainly released from pyrogenic sources rather than petrogenic sources. The emissions of PAHs and MePAHs in this area were probably attributed to uncontrolled burning of e-waste and agricultural by-products, domestic coal and biomass combustion, and traffic activities. Carcinogenicity and mutagenicity of PAHs in the e-waste workshop soils were significantly higher than those of the field soils; however, the incremental lifetime cancer risk of PAH-contaminated soils in this study ranged from 5.5 × 10-9 to 4.6 × 10-6, implying acceptable levels of human health risk. Meanwhile, concentrations of some compounds such as phenanthrene, anthracene, fluoranthene, benz[a]anthracene, and benzo[a]pyrene in several soil samples exceeded the maximum permissible concentrations, indicating the risk of ecotoxicological effects.

Targeted metabolome analysis of the dog brain exposed to PCBs suggests inhibition of oxidative phosphorylation by hydroxylated PCBs.

Canis lupus familiaris (domestic dog) possess a high capacity to metabolize higher-chlorinated polychlorinated biphenyls (PCBs) to thyroid hormone (TH)-like hydroxylated PCB metabolites (OH-PCBs). As a result, the brain could be at high risk of toxicity caused by OH-PCBs. To evaluate the effect of OH-PCBs on dog brain, we analyzed OH-PCB levels in the brain and the metabolome of the frontal cortex following exposure to a mixture of PCBs (CB18, 28, 70, 77, 99, 101, 118, 138, 153, 180, 187, and 202). 4-OH-CB202 and 4-OH-CB107 were major OH-PCBs in the brain of PCB-exposed dogs. These OH-PCBs were associated with metabolites involved in urea cycle, proline-related compounds, and purine, pyrimidine, glutathione, and amino-acid metabolism in dog brain. Moreover, adenosine triphosphate levels in the PCBs exposure group were significantly lower than in the control group. These results suggest that OH-PCB exposure is associated with a disruption in TH homeostasis, generation of reactive oxygen species, and/or disruption of oxidative phosphorylation (OXPHOS) in brain cells. Among them, OXPHOS disturbance could be associated with both disruptions in cellular amino-acid metabolism and urea cycle. Therefore, an OXPHOS activity assay was performed to evaluate the disruption of OXPHOS by OH-PCBs. The results indicated that 4-OH-CB107 inhibits the function of Complexes III, IV, and V of the electron transport chain, suggesting that 4-OH-CB107 inhibit these complexes in OXPHOS. The neurotoxic effects of PCB exposure may be mediated through mitochondrial toxicity of OH-PCBs in the brain.

Evaluation of a data-processing method for target and non-target screening using comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry for environmental samples.

We evaluated the possibility of semi-automatic target and non-target screening by comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry (GC×GC-HRToFMS) by using estuarine sediment samples. Two-way screening consisting of compound-based (target screening) and data-based (non-target screening) analyses was performed by using two original software programs, including mass-spectral deconvolution software based on non-negative matrix factorization, the NIST Mass Spectral Library, and an in-house accurate mass spectral library with a retention index (RI) for the 1st column. Target screening detected 47 organohalogen compounds, including polychlorinated biphenyls, polybrominated diphenyl ethers and organochlorine pesticides, in the sediment sample. Among about 54,000 peaks detected in the non-target screening, 53.6% showed match factors (MF) of ≥ 700 in an automatic mass spectral library search using the peak-top mass spectra. Both mass error of molecular ions and RI error were calculated automatically for the first-hit compounds in the library search; 0.03% of peaks passed all criteria, namely MF ≥ 700, mass error ≤±â€¯20 ppm, RI error ≤ ±â€¯20, and intensity of molecular ion ≥ 10,000. Two compounds-a phosphorus flame retardant and a brominated phenol-were tentatively identified in the non-target screening process. The advantages of semi-automatic GC×GC-HRToFMS data processing with the two original software programs is its simplicity, high reproducibility, and shortened time for processing a large volume data. The results suggest that an In-source HiRes search-i.e. library matching using accurate mass spectra-is useful and could be applied for non-target screening using high-resolution MS in the future.

Seasonal variation of atmospheric organochlorine pesticides and polybrominated diphenyl ethers in Parangipettai, Tamil Nadu, India: Implication for atmospheric transport.

Past studies have reported several persistent organic pollutants (POPs) in different environmental matrices from a tropical coastal site, Parangipettai (PI), located along the bank of the Vellar River in Tamil Nadu, south India. Hence to fill the data gap after the strict ban on several POPs, high volume air sampling was conducted in PI to study the variability of atmospheric organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) during summer, pre-monsoon and monsoon seasons. Emission source regions were tracked by using five days back trajectory analysis. Range of air concentrations in pg/m3 were: dichlorodiphenyltrichloroethane (DDT), 13 - 1976; hexachlorocyclohexane (HCH), 260-1135, hexachlorocyclobenzene (HCB), 52-135, chlordanes, 36-135 and endosulfans, 66-1013. Six PBDE congeners ranged between 25 and 155 pg/m3 with the highest concentration in summer followed by pre-monsoon and monsoon. Atmospheric DDT and HCH in PI have drastically reduced from the past report thereby showing the strict ban on agricultural use of these compounds. During monsoon, fresh source of o,p'-DDT, trans-chlordane and α-endosulfan was evident. Higher level of endosulphan sulfate in PI seems to be likely affected by the air mass, originating from a neighbouring state Kerela, where endosulfan has been extensively used for cashew plantations. Similarly in summer, the day recorded with the highest level of PBDEs, the sample was concurrently impacted by air parcel comprised of two major clusters, 1 (25%) and 2 (49%) that traversed through the metropolitan cities like Bangalore and Chennai. Dominance of BDE-99 over BDE-47 in PI is in line with the PBDE profile reported from Chennai city during similar time frame. Average concentration of tetra and penta BDE congeners in summer samples were nearly 2-3 folds higher than pre-monsoon or monsoon. Given the fact that strong localised sources for heavier BDE congeners are lacking in PI, regional atmospheric transport from the strong emission source regions in Chennai might have impacted PBDE concentration in PI.

Lead in duplicate diet samples from an academic community.

Lead is a naturally occurring element that with the advent of the industrial era became a serious environmental and public health issue. Leaded gasoline, lead based paints, use of lead in plumbing and water pipes, ceramics with lead-containing glazes and tobacco smoke are potential sources of lead exposure for humans. Despite these multiple sources, food is still considered the most important one for the general non-smoking population. Hence, in the present study, the dietary intake of lead was determined in duplicate diet samples provided by 30 participants working or studying at University of Aveiro, Portugal. Pb was detected in all the analysed samples with values ranging between 0.009 and 0.10mgkg-1 ww which correspond to estimated daily intakes between 0.22 and 3.5µgkg-bw-1day-1. Risk estimations disclose that at least 3.3% and 26.7% of the participants might suffer cardiovascular and nephrotoxic effects, respectively.

[Relationship between Arsenic (+3 Oxidation State) Methyltransferase Genetic Polymorphisms and Methylation Capacity of Inorganic Arsenic].

Arsenic metabolism affects the susceptibility of humans to arsenic toxicity; therefore, clarification of the factors associated with individual variations in arsenic metabolism is an important task. Genetic polymorphisms such as single nucleotide polymorphisms (SNPs) in arsenic (+3 oxidation state) methyltransferase (AS3MT), which can methylate arsenic compounds using S-adenosyl-l-methionine (AdoMet), have been reported to modify arsenic methylation. In this review, we summarize studies conducted by us in Vietnam and by others on the association of AS3MT genetic polymorphisms with arsenic metabolism as well as human health effects. Most of the SNPs in AS3MT showed inconsistent results in terms of genotype-dependent differences in arsenic metabolism among the studies. However, AS3MT 12390 (rs3740393) and 14458 (rs11191439) were consistently related to arsenic methylation regardless of the study population: AS3MT 12390 (rs3740393) affected the second step of methylation of arsenic, whereas 14458 (rs11191439) affected the first methylation step.

Spatial and temporal variation of PCBs and organochlorine pesticides in the Antarctic minke whales, Balaenoptera bonaerensis, in the period 1987-2005.

Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and chlordane compounds (CHLs) were determined in the blubber of males (20-25 years old) of Antarctic minke whales, Balaenoptera bonaerensis, from the International Whaling Commission (IWC) management Areas IV (70°-130°E) and V (130°E-170°W), south 60°S. The ranges of concentrations (ng g(-1) lipid wt.) for each compound were, PCBs: 7.7-89; DDTs: 29-340; HCHs: 0.20-4.3; HCB: 75-430; CHLs: 10-120, which were much lower than those in common minke whales, Balaenoptera acutorostrata, from the northern hemisphere. The levels of PCBs, HCHs, HCB and CHLs in Area IV were significantly higher than those in Area V, while the levels of DDTs in both areas were similar. For comparing the fate among four pesticides in the Antarctic Ocean avoiding the effect of variance due to food intake, the ratios of the pesticides to PCBs, which has an extremely high chemical stability and environmental persistence, were examined. The HCHs/PCBs ratio decreased by a factor of about 20 in a span of 16 years in both Areas IV and V, while temporal trends of DDTs/PCBs, HCB/PCBs and CHLs/PCBs ratios were not observed. These results indicate that PCBs, DDTs, HCB and CHLs levels did not vary or slightly decreased in Areas IV and V during the study period. However HCHs levels clearly decreased. Spatial differences seems to be related to differences in food intake among whales, and temporal differences seems to be related to the length stay of OCs in the Antarctic Ocean.

Aryl hydrocarbon receptor mediated activities in road dust from a metropolitan area, Hanoi-Vietnam: contribution of polycyclic aromatic hydrocarbons (PAHs) and human risk assessment.

Dioxin-Responsive Chemical-Activated LUciferase gene eXpression assay (DR-CALUX) was applied to assess the total toxic activity of the mixture of PAHs and related compounds as well as dioxin-related compounds in road dust from urban areas of Hanoi, Vietnam. Road dust from Hanoi contained significantly higher DR-CALUX activities (3 to 39, mean 20 ng CALUX-TEQ/g dw) than those from a rural site (2 to 13, mean 5 ng CALUX-TEQ/g dw). The total concentrations of 24 major PAHs (Σ24PAHs) in urban road dust (0.1 to 5.5, mean 2.5 µg/g dw) were also 6 times higher than those in rural road dust (0.08 to 1.5, mean 0.4 µg/g dw). Diagnostic ratios of PAHs indicated vehicular engine combustion as the major PAH emission source in both sites. PAHs accounted for 0.8 to 60% (mean 10%) and 2 to 76% (mean 20%) of the measured CALUX-TEQs in road dust for Hanoi the rural site, respectively. Benzo[b]-/benzo[k]fluoranthenes were the major TEQ contributors among PAHs, whereas DRCs contributed <0.1% to CALUX-TEQs for both rural and urban sites. These results suggest TEQ contribution of other aryl hydrocarbon receptor agonists in road dust. Significant PAH concentrations in urban dust indicated high mutagenic and carcinogenic potencies. Estimated results of incremental life time cancer risk (ILCR) indicated that Vietnamese populations, especially those in urban areas such as Hanoi, are potentially exposed to high cancer risk via both dust ingestion and dermal contact. This is the first study on the exposure risk of AhR agonists, including PAHs and DRCs, in urban road dust from a developing country using a combined bio-chemical analytical approach.

Simultaneous detection of multiple hydroxylated polychlorinated biphenyls from a complex tissue matrix using gas chromatography/isotope dilution mass spectrometry.

In this study, we developed a comprehensive, highly sensitive, and robust method for determining 53 congeners of three to eight chlorinated OH-PCBs in liver and brain samples by using isotope dilution gas chromatography (GC) coupled with electron capture negative ionization mass spectrometry (ECNI-MS). These results were compared with those from GC coupled with electron ionization high-resolution mass spectrometry (EI-HRMS). Clean-up procedures for analysis of OH-PCBs homologs in liver and brain samples involve a pretreatment step consisting of acetonitrile partition and 5% hydrated silica-gel chromatography before derivatization. Recovery rates of tri- and tetra-chlorinated OH-PCBs in the acetonitrile partition method followed by the 5% hydrated silica-gel column (82% and 91%) were higher than conventional sulfuric acid treatment (2.0% and 3.5%). The method detection limits of OH-PCBs for each matrix obtained by GC/ECNI-MS and GC/EI-HRMS were 0.58-2.6 pg g(-1) and 0.36-1.6 pg g(-1) wet wt, respectively. Recovery rates of OH-PCB congeners in spike tests using sample matrices (10 and 50 pg) were 64.7-117% (CV: 4.7-14%) and 70.4-120% (CV: 2.3-12%), respectively. This analytical method may enable the simultaneous detection of various OH-PCBs from complex tissue matrices. Furthermore, this method allows more comprehensive assessment of the biological effects of OH-PCB exposure on critical organs.

Similarities in the endocrine-disrupting potencies of indoor dust and flame retardants by using human osteosarcoma (U2OS) cell-based reporter gene assays.

Indoor dust is a sink for many kinds of pollutants, including flame retardants (FRs), plasticizers, and their contaminants and degradation products. These pollutants can be migrated to indoor dust from household items such as televisions and computers. To reveal high-priority end points of and contaminant candidates in indoor dust, using CALUX reporter gene assays based on human osteosarcoma (U2OS) cell lines, we evaluated and characterized the endocrine-disrupting potencies of crude extracts of indoor dust collected from Japan (n = 8), the United States (n = 21), Vietnam (n = 10), the Philippines (n = 17), and Indonesia (n = 10) and for 23 selected FRs. The CALUX reporter gene assays used were specific for compounds interacting with the human androgen receptor (AR), estrogen receptor α (ERα), progesterone receptor (PR), glucocorticoid receptor (GR), and peroxisome proliferator-activated receptor γ2 (PPARγ2). Indoor dust extracts were agonistic to ERα, GR, and PPARγ2 and antagonistic against AR, PR, GR, and PPARγ2. In comparison, a majority of FRs was agonistic to ERα and PPARγ2 only, and some FRs demonstrated receptor-specific antagonism against all tested nuclear receptors. Hierarchical clustering clearly indicated that agonism of ERα and antagonism of AR and PR were common, frequently detected end points for indoor dust and tested FRs. Given our previous results regarding the concentrations of FRs in indoor dust and in light of our current results, candidate contributors to these effects include not only internationally controlled brominated FRs but also alternatives such as some phosphorus-containing FRs. In the context of indoor pollution, high-frequency effects of FRs such as agonism of ERα and antagonism of AR and PR are candidate high-priority end points for further investigation.

Identification of major dioxin-like compounds and androgen receptor antagonist in acid-treated tissue extracts of high trophic-level animals.

We evaluated the applicability of combining in vitro bioassays with instrument analyses to identify potential endocrine disrupting pollutants in sulfuric acid-treated extracts of liver and/or blubber of high trophic-level animals. Dioxin-like and androgen receptor (AR) antagonistic activities were observed in Baikal seals, common cormorants, raccoon dogs, and finless porpoises by using a panel of rat and human cell-based chemical-activated luciferase gene expression (CALUX) reporter gene bioassays. On the other hand, no activity was detected in estrogen receptor α (ERα)-, glucocorticoid receptor (GR)-, progesterone receptor (PR)-, and peroxisome proliferator-activated receptor γ2 (PPARγ2)-CALUX assays with the sample amount applied. All individual samples (n = 66) showed dioxin-like activity, with values ranging from 21 to 5500 pg CALUX-2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (TEQ)/g-lipid. Because dioxins are expected to be strong contributors to CALUX-TEQs, the median theoretical contribution of dioxins calculated from the result of chemical analysis to the experimental CALUX-TEQs was estimated to explain up to 130% for all the tested samples (n = 54). Baikal seal extracts (n = 31), but not other extracts, induced AR antagonistic activities that were 8-150 µg CALUX-flutamide equivalent (FluEQ)/g-lipid. p,p'-DDE was identified as an important causative compound for the activity, and its median theoretical contribution to the experimental CALUX-FluEQs was 59% for the tested Baikal seal tissues (n = 25). Our results demonstrate that combining in vitro CALUX assays with instrument analysis is useful for identifying persistent organic pollutant-like compounds in the tissue of wild animals on the basis of in vitro endocrine disruption toxicity.

Exposure, metabolism, and health effects of arsenic in residents from arsenic-contaminated groundwater areas of Vietnam and Cambodia: a review.

In this review, we summarize the current knowledge on exposure, metabolism, and health effects of arsenic (As) in residents from As-contaminated groundwater areas of Vietnam and Cambodia based on our findings from 2000 and other studies. The health effects of As in humans include severe gastrointestinal disorders, hepatic and renal failure, cardiovascular disturbances, skin pigmentation, hyperkeratosis, and cancers in the lung, bladder, liver, kidney, and skin. Arsenic contamination in groundwater is widely present at Vietnam and Cambodia and the highest As levels are frequently found in groundwater from Cambodia. Sand filter system can reduce As concentration in raw groundwater. The results of hair and urine analyses indicate that residents from these As-contaminated areas are exposed to As. In general, sex, age, body mass index, and As exposure level are significantly associated with As metabolism. Genetic polymorphisms in arsenic (+III) methyltransferase and glutathione-S-transferase isoforms may be influenced As metabolism and accumulation in a Vietnamese population. It is suggested oxidative DNA damage is caused by exposure to As in groundwater from residents in Cambodia. An epidemiologic study on an association of As exposure with human health effects is required in these areas.

Selected organochlorine pesticides in the atmosphere of major Indian cities: levels, regional versus local variations, and sources.

India has extensive production and usage of organochlorine pesticides (OCPs) for agriculture and vector control. Despite this, few data are available on the levels and distribution of OCPs in the urban atmosphere of India. Passive and active air sampling was therefore conducted between Dec 2006 and March 2007 in 7 metropolitan cities: New Delhi, Kolkata, Mumbai, Chennai, Bangalore, Goa, and Agra. Concentrations (pg·m(-3)) were as follows: HCHs 890-17000 (mean: 5400 ± 4110); DDTs 250-6110 (1470 ± 1010); chlordanes 290-5260 (1530 ± 790); endosulfans 240-4650 (1040 ± 610); and hexachlorobenzene 120-2890 (790 ± 510). HCHs observed in India appear to be the highest reported across the globe. Chlordanes and endosulfans are lower than levels reported from southern China. Passive sampling enabled within- and between-city variations to be assessed. As expected, paired-sample t-test analysis revealed higher regional than local variation. Comparisons with the limited data available from studies conducted in 1989 suggest general declines of HCHs and DDTs for most regions. γ-HCH dominated the HCH signal, reflecting widespread use of Lindane in India, although the isomeric composition in Kolkata suggests potential technical HCH use. High o,p'-/p,p'-DDT ratios in northern India indicate recent DDT usage. High HCB levels in the industrial areas of New Delhi and Kolkata indicate ongoing sources. Correlation between trans- and cis-chlordane implies ongoing usage. Endosulfan sulfate generally dominated the endosulfan signal, but high values of α/ß-endosulfan at Chennai, Mumbai and Goa suggest ongoing usage. Backward trajectories were computed using the NOAA HYSPLIT model to trace the air mass history. Result shows local/regional sources of OCPs within India.

Kinetic differences of legacy organochlorine pesticides and polychlorinated biphenyls in Vietnamese human breast milk.

The present study investigated the current contamination status and evaluated several kinetic-related features of organochlorine pesticides (OCPs) and PCBs in human breast milk collected from northern Vietnam. The variation in the levels of these contaminants was found to be strongly associated with total lactation time and dietary habits. OCPs exhibited the characteristics of steadily declining compounds: the overall levels of DDTs and HCHs in the population decreased with a half-time of only 5years and it can be suggested that OCPs depurated relatively fast with breastfeeding (5% per month). PCBs were slower in both regards, with a temporal decrease half-time of 12years and a suggested depuration rate via breastfeeding of 2.5% per month, indicating that the exposure level was still high relative to the human body burden. It was found that the PCB exposure levels of infant from breastfeeding exceeded the reference dose, and this situation may continue for the next two or three decades. Knowledge of these kinetic-related characteristics not only is useful for risk assessment and prediction of future trends of legacy contaminants but also may provide insight regarding similar kinetic processes of emerging persistent pollutants.