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.

Pharmaceuticals and personal care products (PPCPs) in surface water and fish from three Asian countries: Species-specific bioaccumulation and potential ecological risks.

In Asian developing countries, undeveloped and ineffective sewer systems are causing surface water pollution by a lot of contaminants, especially pharmaceuticals and personal care products (PPCPs). Therefore, the risks for freshwater fauna need to be assessed. The present study aimed at: i) elucidating the contamination status; ii) evaluating the bioaccumulation; and iii) assessing the potential risks of PPCP residues in surface water and freshwater fish from three Asian countries. We measured 43 PPCPs in the plasma of several fish species as well as ambient water samples collected from India (Chennai and Bengaluru), Indonesia (Jakarta and Tangerang), and Vietnam (Hanoi and Hoa Binh). In addition, the validity of the existing fish blood-water partitioning model based solely on the lipophilicity of chemicals is assessed for ionizable and readily metabolizable PPCPs. When comparing bioaccumulation factors calculated from the PPCP concentrations measured in the fish and water (BAFmeasured) with bioconcentration factors predicted from their pH-dependent octanol-water partition coefficient (BCFpredicted), close values (within an order of magnitude) were observed for 58-91 % of the detected compounds. Nevertheless, up to 110 times higher plasma BAFmeasured than the BCFpredicted were found for the antihistamine chlorpheniramine in tilapia but not in other fish species. The plasma BAFmeasured values of the compound were significantly different in the three fish species (tilapia > carp > catfish), possibly due to species-specific differences in toxicokinetics (e.g., plasma protein binding and hepatic metabolism). Results of potential risk evaluation based on the PPCP concentrations measured in the fish plasma suggested that chlorpheniramine, triclosan, haloperidol, triclocarban, diclofenac, and diphenhydramine can pose potential adverse effects on wild fish. Results of potential risk evaluation based on the PPCP concentrations measured in the surface water indicated high ecological risks of carbamazepine, sulfamethoxazole, erythromycin, and triclosan on Asian freshwater ecosystems.

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.

Sulfotransferases (SULTs), enzymatic and genetic variation in Carnivora: Limited sulfation capacity in pinnipeds.

Wild carnivorans are one of the most important species due to their high positions in the food chain. They are also highly affected by numerous environmental contaminants through bioaccumulation and biomagnification. Xenobiotic metabolism is a significant chemical defense system from xenobiotics because it degrades the activity of a wide range of chemicals, generally into less active forms, resulting in their deactivation. Sulfotransferases (SULTs) are one of the most important xenobiotic metabolic enzymes, which catalyze the sulfonation of a variety of endogenous and exogenous chemicals, such as hormones, neurotransmitters, and a wide range of xenobiotic compounds. Although SULTs are of such high importance, little research has focused on these enzymes in wild carnivorans. In this study, we clarified the genetic properties of SULTs in a wide range of mammals, focusing on carnivorans, using in silico genetic analyses. We found genetic deficiencies of SULT1E1 and SULT1D1 isoforms in all pinnipeds analyzed and nonsense mutations in SULT1Cs in several carnivorans including pinnipeds. We further investigated the enzymatic activity of SULT1E1 in vitro using liver cytosols from pinnipeds. Using a SULT1E1 probe substrate, we found highly limited estradiol sulfonation in pinnipeds, whereas other mammals had relatively high sulfation. These results suggest that pinnipeds have severely or completely absent SULT1E1 activity, which importantly catalyzes the metabolism of estrogens, drugs, and environmental toxins. This further implies a high susceptibility to a wide range of xenobiotics in these carnivorans, which are constantly exposed to environmental chemicals throughout their lifetime.

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.

Occurrence of Pharmaceutically Active Compounds and Potential Ecological Risks in Wastewater from Hospitals and Receiving Waters in Sri Lanka.

The presence of pharmaceutically active compounds (PACs) in the environment and their associated hazards is a major global health concern; however, data on these compounds are scarce in developing nations. In the present study, the existence of 39 non-antimicrobial PACs and six of their metabolites in wastewater from hospitals and adjacent surface waters in Sri Lanka was investigated from 2016 to 2018. The highest amounts of the measured chemicals, including the highest concentrations of atorvastatin (14,620 ng/L) and two metabolites, mefenamic acid (12,120 ng/L) and o-desmethyl tramadol (8700 ng/L), were detected in wastewater from the largest facility. Mefenamic acid, gemfibrozil, losartan, cetirizine, carbamazepine, and phenytoin were detected in all the samples. The removal rates in wastewater treatment were 100% for zolpidem, norsertaline, quetiapine, chlorpromazine, and alprazolam. There was substantial variation in removal rates of PACs among facilities, and the overall data suggest that treatment processes in facilities were ineffective and that some PAC concentrations in the effluents were increased. The estimated risk quotients revealed that 14 PACs detected in water samples could pose low to high ecological risk to various aquatic organisms. Compounds such as ibuprofen, tramadol, and chlorpromazine detected in untreated and treated wastewater at these facilities pose a high risk to several aquatic organisms. Our study provides novel monitoring data for non-antimicrobial PAC abundance and the associated potential ecological risk related to hospitals and urban surface waters in Sri Lanka and further offers valuable information on pre-COVID-19 era PAC distribution in the country. Environ Toxicol Chem 2022;41:298-311. © 2021 SETAC.

Determination of six thyroid hormones in dog brain and liver using acidic extraction, mixed-mode cleanup, and liquid chromatography-tandem mass spectrometry.

Thyroid hormones (THs) play a critical role in the regulation of biological processes, such as growth, metabolism, and development, in various animal species. Prohormone L-thyroxine (T4) is secreted from the thyroid gland and carried to peripheral tissues. T4 is then biotransformed to several metabolites which play different roles, mainly by iodothyronine deiodinases. Determination of deiodinated TH metabolites in key organs such as liver and brain would help to understand tissue-specific TH metabolism and homeostasis. In this study, we thus developed a highly sensitive method for the determination of six THs [T4, 3,5,3'-triodo-L-thyronine (T3), 3,3',5'-triiodo-L-thyronine (rT3), 3,5-diiodo-l-thyronine (3,5-T2), 3,3'-diiodo-l-thyronine (3,3'-T2), and 3-iodo-l-thyronine (3-T1)] in the brain and liver by using stored dog samples. The analytical method consisted of ultrasonic-assisted extraction in acetone acidified with formic acid, cleanup with a EVOLUTE® EXPRESS CX cartridge (reversed-phase combined with strong cation-exchange cartridge), and quantification with liquid chromatography-tandem mass spectrometry. Acceptable accuracy (internal standard-corrected recovery: 80%-120%) and intra- and inter-day precision (coefficient of variation: <6% and <15%, respectively) (n = 3/ batch, three days) were obtained for both brain and liver samples. In addition, low method detection limits were achieved for both brain (0.013-0.12 ng g-1) and liver (0.030-0.78 ng g-1), which resulted in the quantitation of not only T4, T3, and rT3, but also 3,3'-T2 in both dog brain and liver samples. The developed method was successfully applied to the analysis of THs in the brain and liver of dogs (Canis lupus familiaris) which were exposed to polychlorinated biphenyls (PCBs). As a result, concentration ratios of rT3/T4 and 3,3'-T2/T3 in the PCB-exposed dogs were significantly higher than those in the control groups, suggesting the enhanced inner (tyrosyl)-ring deiodination (5-deiodination) by PCB exposure. The analytical method developed in the present study enables comprehensive evaluation of alterations in peripheral TH metabolism which are caused by exposure to environmental pollutants.

Nontarget Screening of Organohalogen Compounds in the Liver of Wild Birds from Osaka, Japan: Specific Accumulation of Highly Chlorinated POP Homologues in Raptors.

Nontarget screening studies have recently revealed the accumulation of typically unmonitored organohalogen compounds (OHCs) in various marine animals, but information for terrestrial food chains is still lacking. This study investigated the accumulation profiles of known and unknown OHCs in the liver of representative wild bird specimens from Osaka, Japan using nontarget analysis based on two-dimensional gas chromatography-time-of-flight mass spectrometry. A large number of unmonitored OHCs were identified, including anthropogenic contaminants and marine halogenated natural products (HNPs), and their accumulation profiles were considered to be influenced by terrestrial and brackish water-based diets. Anthropogenic OHCs were highly accumulated in terrestrial predator species (peregrine falcon, hawks, and black kite), and some unmonitored highly chlorinated contaminants reached the levels of microgram per gram lipid in the liver, i.e., C10-/C15-based chlordane related compounds (CHLs) and their epoxides, dichlorodiphenyldichloroethylene (DDE) homologues, and polychlorinated terphenyls (PCTs). In contrast, HNPs were accumulated at higher levels in piscivorous birds (gray heron and common cormorant). Considering the enrichment of the unmonitored C10-/C15-based CHLs, PCTs, and DDE homologues relative to structurally similar persistent organic pollutants (POPs) in high trophic-level species such as raptors, further studies are needed to elucidate their environmental levels, behavior in terrestrial food chains, and ecotoxicological impacts.

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.

The association between antimicrobials and the antimicrobial-resistant phenotypes and resistance genes of Escherichia coli isolated from hospital wastewaters and adjacent surface waters in Sri Lanka.

The presence of antimicrobials, antimicrobial-resistant bacteria (ARB), and the associated antimicrobial resistance genes (ARGs) in the environment is a global health concern. In this study, the concentrations of 25 antimicrobials, the resistance of Escherichia coli (E. coli) strains in response to the selection pressure imposed by 15 antimicrobials, and enrichment of 20 ARGs in E. coli isolated from hospital wastewaters and surface waters were investigated from 2016 to 2018. In hospital wastewaters, clarithromycin was detected at the highest concentration followed by sulfamethoxazole and sulfapyridine. Approximately 80% of the E. coli isolates were resistant, while 14% of the isolates exhibited intermediate resistance against the tested antimicrobial agents. Approximately 61% of the examined isolates were categorized as multidrug-resistant bacteria. The overall abundance of phenotypes that were resistant toward drugs was in the following order: ß-lactams, tetracycline, quinolones, sulfamethoxazole/trimethoprim, aminoglycosides, and chloramphenicol. The data showed that the E. coli isolates frequently harbored blaTEM, blaCTX-M, tetA, qnrS, and sul2. These results indicated that personal care products were significantly associated with the presence of several resistant phenotypes and resistance genes, implying their role in co-association with multidrug resistance. Statistical analysis also indicated a disparity specific to the site, treatment, and year in the data describing the prevalence of ARB and ARGs and their release into downstream waters. This study provides novel insights into the abundance of antimicrobial, ARB and ARGs in Sri Lanka, and could further offer invaluable information that can be integrated into global antimicrobial resistance databases.

Snakes as bimonitors of environmental pollution: A review on organic contaminants.

Monitoring data on organic pollutants published between the late 1960s and 2020 are reviewed to provide comprehensive and updated insights into their bioaccumulation characteristics, sources, and fate in snakes. Multiple organic pollutant classes including pesticides, polychlorinated biphenyls, chlorinated paraffins, dioxin-related compounds, alkanes, polycyclic aromatic hydrocarbons, flame retardants, plasticizers, etc., were detected in various aquatic and terrestrial snake species with concentrations and patterns varying between species and locations. In general, higher concentrations of organic pollutants were found in snakes collected from contaminated sites (e.g., densely populated, pesticide-treated, and waste processing areas), suggesting that snakes can serve as good biomonitors of environmental pollution caused by organic contaminants. Factors influencing concentrations and patterns of organic pollutants in snakes are discussed, providing an overview of current understanding about their accumulation, transformation, and elimination processes. Potential negative effects associated with organic pollutants in snakes and their predators are also considered. Based on such discussions, research gaps and future perspectives on the utilization of snake biomonitoring studies are addressed, heading towards an effective monitoring and assessment scheme for a variety of legacy and emerging organic pollutants in the environment.

Anthropogenic and natural organohalogen compounds in melon-headed whales (Peponocephala electra) stranded along the Japanese coastal waters: Temporal trend analysis using archived samples in the environmental specimen bank (es-BANK).

The present study determined recent accumulation levels of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), polychlorinated diphenyl ethers (PCDEs), methoxylated-PBDEs (MeO-PBDEs) and 2,3,3',4,4',5,5'-heptachloro-1'-methyl-1,2'-bipyrrole (Q1) in the blubber of melon-headed whales (Peponocephala electra) stranded along the Japanese coastal waters in 2015 and examined temporal trends of these organohalogen compound (OHC) levels by analyzing blubber samples of this species archived in the environmental specimen bank which were collected in 1982, 2001, 2002, 2006, 2010 and 2011. The median concentrations in melon-headed whales stranded recently were in the order of DDTs ≈ PCBs > HBCDDs > Q1 > CHLs > MeO-PBDEs > PBDEs > HCB > HCHs > PCDEs, indicating that considerable amounts of HBCDDs, in addition to DDTs and PCBs, have been transported to tropical and subtropical waters of the open ocean and pelagic whale species might be exposed to relatively high levels of these OHCs. Temporal trend analyses of OHC levels in the blubber of melon-headed whales revealed significant decrease for anthropogenic OCs such as DDTs, PCBs, HCB, HCHs and PCDEs, and significant increase for CHLs, PBDEs, HBCDDs, MeO-PBDEs and Q1 since 1982. Besides, the analyses from 2001 to 2015 showed no decreasing trends (unchanged) for some PCB congeners, p,p'-DDE, cis- and trans-nonachlors, Q1, BDE-47, -100 and -154, and significantly increasing trends for α-HBCDD and 6MeO-BDE47, suggesting their chronic exposure for this pelagic whale species.

Contamination of habu (Protobothrops flavoviridis) in Okinawa, Japan by persistent organochlorine chemicals.

Persistent organochlorine chemicals (OCs), including chlordane compounds (CHLs), DDTs, PCBs, and chlorinated dioxins and related compounds (DRCs), were examined in the adipose tissue and liver from 33 specimens of habu (Protobothrops flavoviridis), a species of venomous pit viper endemic to the Japanese Southwest Islands. The median concentrations of CHLs, DDTs, and PCBs in adipose tissue of 22 habus collected from an urban area were 4400 ng g-1 lipid weight (lw), 610 ng g-1 lw, and 1600 ng g-1 lw, respectively. Their DDT and PCB concentrations were higher in comparison with the specimens from a rural area. Liver of 10 specimens from the urban area were subjected to DRCs analysis, and PCDDs, PCDFs, and DL-PCBs were detected with median values of 1300, 350, and 150,000 pg g-1 lw, respectively. Among PCDD/F congeners, octa-CDD was detected at the highest concentrations in seven liver samples, but considerable concentrations of penta- and hexa-CDD/Fs were found in two samples. Relatively higher concentrations of PCB, DDTs, and PCDD/Fs were found in habus collected within 1 km of the boundary of military facilities, suggesting that OCs from some unknown sources of these OCs inside and/or around some of the facilities accumulated in habus.

Rapid analysis of 65 pharmaceuticals and 7 personal care products in plasma and whole-body tissue samples of fish using acidic extraction, zirconia-coated silica cleanup, and liquid chromatography-tandem mass spectrometry.

The presence of pharmaceuticals and personal care products (PPCPs) in aquatic systems has raised concern about their potential adverse effects on aquatic organisms. Considering the fact that the physiological/biological effects of PPCPs are triggered when their concentrations in the organism exceeds the respective threshold values, it is important to understand the bioconcentration and toxicokinetics of PPCPs in aquatic organisms. In the present study, we developed a convenient analytical method for the determination of 65 pharmaceuticals and 7 personal care products (log Kow = 0.14-6.04) in plasma and whole-body tissues of fish. The analytical method consists of ultrasound-assisted extraction in methanol/acetonitrile (1:1, v/v,) acidified with acetic acid-ammonium acetate buffer (pH 4), cleanup on a HybridSPE®-Phospholipid cartridge (zirconia-coated silica cartridge), and quantification with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Acceptable accuracy (internal standard-corrected recovery: 70%-120%) and intra- and inter-day precision (coefficient of variation: <15%) were obtained for both plasma and whole-body tissue samples. In addition, low method detection limits were achieved for both plasma (0.0077 to 0.93 ng mL-1) and whole-body tissue (0.022 to 4.3 ng g - 1 wet weight), although the developed method is simple and fast - a batch of 24 samples can be prepared within 6 h, excluding the time for measurement with LC-MS/MS. The developed method was successfully applied to the analysis of PPCPs in plasma and whole-body tissue samples of fish collected in a treated wastewater-dominated stream, for a comprehensive evaluation of their bioconcentration properties. The analytical method developed in the present study is sufficiently accurate, sensitive, and rapid, and thus highly useful for the comprehensive evaluation of PPCP residues in fish and would aid in future exposome and risk assessment.

Mother to Fetus Transfer of Hydroxylated Polychlorinated Biphenyl Congeners (OH-PCBs) in the Japanese Macaque (Macaca fuscata): Extrapolation of Exposure Scenarios to Humans.

Prenatal hydroxylated polychlorinated biphenyls (OH-PCBs) exposure may disrupt fetal brain development during the critical period of thyroid hormone (TH) action. However, there are limited studies on the OH-PCB transfer to the fetal brain, particularly in primates. In this study, we selected the Japanese macaque (Macaca fuscata) as a model animal for the fetal transfer of OH-PCBs in humans and revealed OH-PCB concentrations and their relationships in maternal and fetal blood, liver, and brain. l-thyroxine (T4)-like OH-PCBs including 4OH-CB187, a major congener in humans, were found in high proportions in the blood, liver, brain, and placenta of pregnant Japanese macaques. OH-PCBs were detected in the fetal brain and liver in the first trimester, indicating their transfer to the brain in the early pregnancy stage. 4OH-CB187 and 4OH-CB202 were the major congeners found in fetal brain, indicating that these T4-like OH-PCBs are transported from maternal blood to the fetal brain via the placenta. These results indicate that further studies are needed on the effects of OH-PCBs on the developing fetal brain.

Coastal biomonitoring survey on persistent organic pollutants using oysters (Saccostrea mordax) from Okinawa, Japan: Geographical distribution and polystyrene foam as a potential source of hexabromocyclododecanes.

The present study determined contamination levels of POPs, such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs), in oysters (Saccostrea mordax) collected throughout the seacoast of Okinawa, Japan and their geographic distribution. PCBs, DDTs, CHLs, PBDEs and HBCDs were detected in almost all the oyster samples analyzed and higher concentrations of PCBs, DDTs and CHLs were found in oysters from southwestern populated areas. On the other hand, HBCDs in oysters showed similar levels throughout Okinawa and the highest concentration in a northern rural site with less human and industrial activities, although oyster concentrations of PBDEs were relatively lower. When POPs in expanded polystyrene (EPS) buoys and polystyrene foam debris floated and drifted on coastal seawater were analyzed, extremely high concentrations of HBCDs were detected in some of these EPS buoys and polystyrene foam debris but other POPs were below the limit of detection in all the samples. To evaluate the specific exposure route of HBCDs for oysters, we further analyzed HBCD diastereomers, and PCB congeners by way of comparison, in seawater and sediment samples collected at an urban site and a rural site and estimated their biota (oyster)-sediment accumulation factors (BSAF) and bioaccumulation factors (BAF). Interestingly, the highest log BAF values were found for α-HBCD despite its lower log Kow than those of γ-HBCD and PCB congeners, although log BSAF values for HBCDs were lower than those for PCBs. Considering that α-HBCD was detected in a few polystyrene foam samples as the predominant diastereomer, oysters inhabiting the coastal region of Okinawa might be frequently exposed to micronized polystyrene foam particles containing HBCDs.

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.

Nontarget and Target Screening of Organohalogen Compounds in Mussels and Sediment from Hiroshima Bay, Japan: Occurrence of Novel Bioaccumulative Substances.

Recent screening surveys have shown the presence of unknown halogenated compounds in the marine environment at comparable levels to persistent organic pollutants (POPs). However, their exposure levels and profiles in marine organisms and bioaccumulative potentials remain unclear. The present study performed nontarget/target screening of organohalogen compounds (OHCs) in mussel and sediment samples collected from Hiroshima Bay, Japan, in 2012 and 2018 by using integrated analyses of two-dimensional gas chromatography-high resolution time-of-flight mass spectrometry (GC×GC-HRToFMS) and magnetic sector GC-HRMS. Nontarget analysis by GC×GC-HRToFMS revealed the detection of approximately 60 OHCs including unknown mixed halogenated compounds (UHC-Br3-5Cl) with molecular formulae of C9H6Br3ClO, C9H5Br4ClO, and C9H4Br5ClO in the mussel. Interestingly, UHC-Br3-5Cl concentrations in the mussel samples, which were semi-quantified by GC-HRMS, were comparable to or higher than those of POPs at all the locations surveyed, and their geographical distribution patterns differed from those of other OHCs. These results suggest that UHC-Br3-5Cl are ubiquitous in coastal waters of Hiroshima Bay and derived from a specific source(s). The biota-sediment accumulation factors (BSAFs) of UHC-Br3-5Cl, estimated for a paired sample set of mussel (ng/g lw) and sediment (ng/g TOC), were 1 order of magnitude higher than those for POPs with similar log Kow values, indicating their high bioaccumulative potential.

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.