Dichlorodiphenyltrichloroethane And Its Metabolites Research Articles

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.

Preliminary assessment of persistent organic pollutants (POPs) in tissues of Risso's dolphin (Grampus griseus) specimens stranded along the Italian coasts

Ecotoxicological and pathological research on Grampus griseus (Cuvier, 1812) (Risso's dolphins) is scarce both globally and in the Mediterranean Sea. This species has been classified as “Vulnerable” by the International Union for Conservation of Nature (IUCN) in the Mediterranean Sea.To evaluate the presence of “persistent organic pollutants” (POPs), especially organochlorine compounds (OCs), in the animals, chemical analyses were performed on tissues and organs of Risso's dolphin stranded along the Italian coasts between 1998 and 2021. Toxic contaminants such as hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) were examined in the blubber, liver, muscle, and brain of 20 animals, and data was correlated with sex, age, and stranding locations.

Highly contaminated river otters (Lontra canadensis) are effective biomonitors of environmental pollutant exposure

River otters (Lontra canadensis) are apex predators that bioaccumulate contaminants via their diet, potentially serving as biomonitors of watershed health. They reside throughout the Green-Duwamish River, WA (USA), a watershed encompassing an extreme urbanization gradient, including a US Superfund site slated for a 17-year remediation. The objectives of this study were to document baseline contaminant levels in river otters, assess otters’ utility as top trophic-level biomonitors of contaminant exposure, and evaluate the potential for health impacts on this species. We measured a suite of contaminants of concern, lipid content, nitrogen stable isotopes (δ15N), and microsatellite DNA markers in 69 otter scat samples collected from twelve sites. Landcover characteristics were used to group sampling sites into industrial (Superfund site), suburban, and rural development zones. Concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ether flame-retardants (PBDEs), dichlorodiphenyl-trichloroethane and its metabolites (DDTs), and polycyclic aromatic hydrocarbons (PAHs) increased significantly with increasing urbanization, and were best predicted by models that included development zone, suggesting that river otters are effective biomonitors, as defined in this study. Diet also played an important role, with lipid content, δ15N or both included in all best models. We recommend river otter scat be included in evaluating restoration efforts in this Superfund site, and as a potentially useful monitoring tool wherever otters are found. We also report ΣPCB and ΣPAH exposures among the highest published for wild river otters, with almost 70% of samples in the Superfund site exceeding established levels of concern.

Bioaccumulation and Biomagnification of Polychlorinated Biphenyls and Dichlorodiphenyltrichloroethane in Biota from Qilianyu Island, South China Sea.

Six biota species were collected from Qilianyu Island, South China Sea to determine the bioaccumulation and biomagnification of polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of ΣPCBs and ΣDDTs in biota from Qilianyu Island ranged from 6.88 to 519.1 ng/g lipid weight (lw) and 7.0 to 19,413 ng/g lw, respectively. Significant differences for PCBs and DDTs concentrations were found among the six biota species from Qilianyu Island. The levels of PCBs and DDTs in intermediate egret were significantly higher than the other five biota species, which can be attributed to their different feeding and living habits. Significantly negative relationships between concentrations of PCBs and DDTs and δ13C values in the six biota species confirmed that dietary source is an important factor to determine the levels of PCBs and DDTs in biota species. ΣPCBs, ΣDDTs, PCB 28/31, PCB 52, and p,p′-DDE were biomagnified in the biota species from Qilianyu Island, and native species are suitable for studying the biomagnification of the contaminants. The toxic equivalent concentrations in birds from Qilianyu Island were significantly and positively correlated with PCBs concentrations, indicating that high concentrations of non- and mono-ortho-PCB congeners may induce adverse effects on bird species.

Health risks of exposure to soil-borne dichlorodiphenyltrichloroethanes (DDTs): A preliminary probabilistic assessment and spatial visualization

Residues of dichlorodiphenyltrichloroethane and its metabolites (DDTs) in soils continue to severely threaten and endanger human health. This present study comprehensively interprets the health risks associated with exposure to soil-borne DDTs and also identifies the spatial visualization of risks at a large regional scale in Fujian, China. There was significant spatial variability of human risk across the region, while levels of health risk displayed a significant positive correlation with population density (p < 0.05). High risk levels occurred mostly in the coastal areas in northeastern Fujian, with additional hotspots in inland areas. The highest total incremental lifetime cancer risks (ILCRs) occurred in Sanming, reaching up to 9.52 × 10−5, 3.27 × 10−5, and 1.76 × 10−4 for children, teens, and adults, respectively. Further, the highest hazard index (HI) value was observed in Fuzhou, reaching up to 6.09, 3.84, and 2.37, respectively. The 95% confidence interval of data regarding ILCRs exceeded the recognized safe threshold, whereas the HI has been deemed accepted. Adults were identified as the most susceptible population in terms of cancer risks, with o,p′-DDT being the primary contributor of ILCRs. Moreover, children were showed to be the most vulnerable in terms of non-cancer risks, with p,p′-DDD being the main contributor of HI. Food ingestion appeared to be the dominant exposure pathway, for both cancer and non-cancer risks. The concentration of DDTs (Csoil) and exposure duration (ED) also greatly influenced the risk, together contributing to over 99% of the ILCRs and HI.

Estimation of dietary intake and sources of organohalogenated contaminants among infants: 24-h duplicate diet survey in Fukuoka, Japan

The widespread occurrence of persistent organic pollutants (POPs) in the environment is a matter of concern. In this study, selected organohalogenated contaminants, including dichlorodiphenyltrichloroethane and its metabolites (DDTs) polychlorinated biphenyls (PCBs), chlordanes (CHLs), hexachlorobenzene (HCB), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), tetrabromobisphenol A (TBBPA), 2,4,6-tribromophenol (TBP), were measured in complete meal sets (24-h duplicate-diet) of Japanese infants to investigate the levels, profiles, and possible sources of contamination. In total, 46 whole-day meals of infants (7–24-months old) were collected during 2017 from Fukuoka, Japan. To the best of our knowledge, this is the first report based on the duplicate-diet method for infants. The median intakes among the POP groups were highest for ΣDDTs (18 ng/day, maximum 251 ng/day), followed by ΣPCBs (17 ng/day, maximum 198 ng/day), ΣCHLs (14 ng/day, maximum 105 ng/day), HCB (11 ng/day, maximum 64 ng/day), TBP (3.5 ng/day, maximum 109 ng/day), ΣHBCDs (1.9 ng/day, maximum 70 ng/day), TBBPA (0.72 ng/day, maximum 34 ng/day), and ΣPBDEs (0.11 ng/day, maximum 4.5 ng/day). Among the PCBs, PCB-138 and PCB-153 were the most abundant congeners (27% and 23%, respectively). p,p’-DDE, the major DDT metabolite, accounted for 96% of total DDTs. Among PBDEs, BDE47 was the only detected congener (present in 4% of the samples). The dietary intake of the targeted compounds was lower than the intake via breast milk, suggesting that the exposure from baby food was limited. In the principal component analysis, chlorinated and brominated compounds were separated on principal component 1, while TBP and α-HBCD were separated on principal component 2, likely suggesting a differing emission time trend or source. PCB-153, PCB-138, trans-chlordane, cis-chlordane, and trans-nonachlor were correlated with seafood consumption (Spearman's ρ = 0.45 to 0.57, p < 0.05), while TBP was correlated with seaweed consumption (Spearman's ρ = 0.46, p < 0.05). Also, four species of commercial edible seaweed in Japan were analyzed to confirm the findings of the duplicate-diet study. The relatively high concentration of TBP (5.5 ± 6.6 ng/g wet weight) was observed in the seaweed samples, indicating that seaweed is a potential exposure source of TBP.

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.

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.

Trophic Magnification of Legacy (PCB, DDT and Hg) and Emerging Pollutants (PFAS) in the Fish Community of a Small Protected Southern Alpine Lake (Lake Mergozzo, Northern Italy)

The biomagnification of mercury, polychlorobiphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs) and perfluoroalkyl acids substances (PFASs) was evaluated in the trophic web of Lake Mergozzo, a small and deep Italian subalpine lake, which has been chosen because it is a protected environment, and discharges into the lake are mostly avoided. Carbon source and relative trophic levels were calculated by using 13C and 15N stable isotopes, respectively, and trophic magnification factors (TMFs) were derived. Zooplankton and thirteen species of fish were collected and analyzed, and the results showed the elevated level of biota contamination from both legacy and emerging pollutants, even if direct discharges were avoided. Concentrations in biota, expressed as sums of compounds, ranged from 0.4 to 60 µg kg−1 wet weight (ww) for PFASs, from 16 to 1.3 104 µg kg−1 lipid content (lw) for DDTs, from 17 to 1.5 104 µg kg−1 lw for PCBs and from 20.0 to 501 µg kg−1 ww for mercury (Hg). TMFs of this deep, cold lake, with a prevalent pelagic trophic chain, were high and clearly indicated fish biomagnification, except for PFAS. The biomagnification capability of PFAS in a fish-only food web was discussed by using the biomagnification of Hg as a benchmark for assessing their bioaccumulation potential.

Evidence for complex sources of persistent halogenated compounds in birds from the south China sea

Persistent halogenated compounds (PHCs), including dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), alternative brominated flame retardants (ABFRs), and dechlorane plus (DP), were analyzed in muscle of six bird species from the South China Sea. DDTs, with concentrations up to 19,000 ng/g lipid weight (lw), were the dominant contaminants contributing to 66–99% of PHCs in birds. Concentrations of PBDEs, ABFRs, and DP ranged from 1.1 to 130, 0.73–40, and 0.21–2.5 ng/g lw, respectively. Historically pollution of DDTs and flame retardants in surrounding Asian lands were the main sources for PHCs in birds. BDE 209 was the primary PBDE congener in all birds. 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE) and decabromodiphenyl ethane (DBDPE) were the main ABFRs. Anti-DP and p,p′-DDE were the dominating compounds of DP and DDTs, respectively. Only concentrations of BDEs 153, 203, 196, and 207, p,p′-DDE, and p,p′-DDD showed significant and positive correlations with δ15N values in samples. The resident birds, red-footed booby (Sula sula), had much lower levels of p,p′-DDE and most of PBDEs than those in migratory birds from the South China Sea. Results of stable isotope ratios of carbon suggest the highly variable food items for the five migratory bird species. The abundance of DBDPE in red-footed booby might be related with the ingestion of plastic debris, which still warrants further verification.

Geographical distribution and risk assessment of dichlorodiphenyltrichloroethane and its metabolites in Perna viridis mussels from the northern coast of the South China Sea

Mussels (Perna viridis) were collected from the northern coast of the South China Sea (NSCS) to investigate the geographical distribution and potential risk of dichlorodiphenyltrichloroethane and its metabolites (DDTs). DDTs had concentrations that ranged from 248 ng/g to 4650 ng/g lipid weight (lw), with an average of 807 ± 932 ng/ng lw. A comparison of the levels of DDTs in mussels indicated that the NSCS is still one of the most polluted areas in the world, although a decreasing trend was observed. DDT metabolites were predominant in all samples, suggesting that historical residue was the main source of DDT pollution. However, there were new inputs of DDTs which likely associated with antifouling paints. The human health risk assessment revealed that the current concentrations of DDTs in mussels might pose little health risk for the consumers.

Interspecies comparison of the residue levels and profiles of persistent organic pollutants in terrestrial top predators

Serum samples from three species of living terrestrial top predators were analysed for six groups of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and polybrominated diphenyl ethers (PBDEs). The study included three carnivore species: lion (Panthera leo), hyena (Hyena brunnea) and cheetah (Acinonyx jubatus). All samples were collected from healthy living animals between 2004 and 2005. Most of the samples (wild lions (n = 50) and hyenas (n = 11)) were collected from various locations within the Kruger National Park and Addo National Park (South Africa), while captive lions (n = 6) and cheetahs (n = 3) were collected from the Antwerp Zoo (Belgium). In general, relatively low levels of POPs were found in the studied species, varying widely within species and locations. Median concentrations of POPs were higher in captive lions (PCBs: 505 pg/mL; DDTs: 270 pg/mL; HCHs: 72 pg/mL; HCB: 34 pg/mL; CHLs: 24 pg/mL; PBDEs: 8 pg/mL) compared to wild lions (DDTs: 274 pg/mL; HCHs: 44 pg/mL; CHLs: 7.9 pg/mL; PCBs: 2.1 pg/mL; HCB: < LOQ; PBDEs: < LOQ). In the wild animals, POPs accumulated in the following order: DDTs > HCHs > CHLs > HCB > PCBs > PBDEs, while in the captive animals, the order was: PCBs > DDTs > CHLs > HCHs > HCB > PBDEs, suggesting differences in the diet of these animals. Furthermore, wild hyena contained significantly higher (p < 0.05) median levels of POPs compared to wild lions, possibly reflecting differences in metabolic capacity and/or feeding habits, together with an uneven distribution of POPs in the area where the animals lived. No previous data are available to compare for similar terrestrial top predators, such as lion, hyena and cheetah. To our knowledge, this is first study on POPs in these three species. The low POP levels found in this study were several orders of magnitude lower than those for other carnivore species, such as polar bears, grizzly bears, brown bears and wolves worldwide. The present study has revealed the need for expanding research and monitoring on occurrence, levels and disposition of POPs in the top predators of the terrestrial environment.

Persistent organic pollutants (POPs) in oriental magpie-robins from e-waste, urban, and rural sites: Site-specific biomagnification of POPs

Plenty of banned and emerging persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane and its metabolites (DDTs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), dechlorane plus (DP), and decabromodiphenyl ethane (DBDPE), were measured in oriental magpie-robins from an e-waste recycling site, an urban site (Guangzhou City), and a rural site in South China. Median concentrations of DDTs, PCBs, PBDEs, DP, and DBDPE ranged from 1,000–1,313, 800-59,368, 244-5,740, 24.1–127, and 14.7–36.0 ng/g lipid weight, respectively. Birds from the e-waste site had significantly higher concentrations of PCBs and PBDEs than those from urban and rural sites (p < 0.05), implying contamination of PCBs and PBDEs brought by e-waste recycling activities. DDTs were the predominant POPs in birds from urban and rural sites. The values of δ15N were significantly and positively correlated with concentrations of p,p′-DDE and low-halogenated chemicals in samples from the e-waste site (p < 0.05), indicating the trophic magnification of these chemicals in birds. However, concentrations of most POPs were not significantly correlated with the δ15N values in birds from urban and rural sites. PCBs and PBDEs in birds from urban and rural sites were not likely from local sources, and the biomagnification of POPs in different sites needed to be further investigated with caution.

Persistent organic pollutants are still present in surface marine sediments from the Seto Inland Sea, Japan

Although persistent organic pollutants (POPs) are currently banned or strictly controlled under the Stockholm Convention on Persistent Organic Pollutants, POPs are still distributed worldwide due to their environmental persistence, atmospheric transport, and bioaccumulation. Herein we investigated the current concentrations of POPs in the sediments from Seto Inland Sea, Japan and sought to clarify the factors currently controlling the POPs concentration of the surface sediments from Seto Inland Sea. The concentrations of hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and chlordane isomers (CHLs) in sediments from Seto Inland Sea were <0.002-1.20 ng g-1, 0.01-2.51 ng g-1, and 0.01-0.48 ng g-1, respectively. Resuspension increased the concentrations of HCHs, HCB, and DDTs in the surface sediment with the release of historically contaminated pollutants accumulated in a lower layer. We speculate that CHLs in air that were removed by atmospheric deposition affects the concentration of CHLs in surface sediments.

Evaluation of organochlorine pesticide (OCP) residues in meat and edible organs, Iran.

Organochlorine pesticides (OCPs) are a more persistent and lipophilic group of insecticides. The present study aims to evaluate the residues of OCPs in meat, liver, and kidney of the cattle and sheep. A total of 54 samples were obtained from butcheries and local markets in Birjand, east of Iran. The residual contents of aldrin; dieldrin; dichlorodiphenyltrichloroethane; and its metabolites (DDTs), endosulfan isomers, endrin, hexachlorocyclohexane isomers (HCHs), heptachlor, heptachlor epoxide, chlordans, methoxychlor, and hexachlorobenzene (HCB), were analyzed in all samples. OCP residues were extracted by using the QuEChERS technique and quantified by gas chromatography-mass spectrometry (GC-MS). All of the analyzed OCPs were lower than the detection limit. The findings showed that meat and edible organs marketed in this region enjoyed a good status in terms of the residues of OCP. Monitoring of pesticide residues in meat and edible organs is necessary from the public health point of view.

The interactive effect of the season and estuary position on the concentration of persistent organic pollutants in water and sediment from the Cua Dai estuary in Vietnam.

The current study was conducted in the Cua Dai estuary, Vietnam, (1) to assess the status of persistent organic pollutants (POPs) and (2) to examine the interactive effect of season and estuary position on the concentration of the pollutants in surface water and sediment. Fifty-two water and sediment samples were taken in the dry and rainy seasons from inner- and outer-estuary positions to analyze for six POPs, including hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), heptachlor, aldrin, dieldrin, and polychlorinated biphenyl (PCBs). The averaged concentrations of the respective POPs in water samples were 0.07, 0.1, 0.01, 0.03, 0.001, and 0.2 μg L-1 and in sediment samples were 2.6, 3.1, 0.9, 0.2, 0.2, and 121 μg kg-1. Of the six POPs examined, the concentration of DDTs in sediment samples and PCBs in water samples was significantly affected by the interactive effect of the two examined factors. The concentrations of HCHs, DDTs, heptachlor, and aldrin in water samples and of HCHs in sediment samples were significantly higher in the rainy season than in the dry season. Sediment samples collected from the inner position had a significantly higher concentration of HCHs and PCBs than in the outer position. Some mechanisms possibly influenced the varying POP concentration could include (1) greater riverine discharge in the rainy season and (2) the sea dilution effect in the outer position. Therefore, the concentration of the individual examined POPs in water and sediment in the Cua Dai estuary significantly depended on either the season, estuary position, or their combination.

Global Monitoring of Persistent Organic Pollutants (POPs) Using Seabird Preen Gland Oil.

Situated at high positions on marine food webs, seabirds accumulate high concentrations of persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), and hexachlorocyclohexanes (HCHs). Our previous studies proposed the usefulness of seabirds preen gland oil as a nondestructive biomonitoring tool. The present study applied this approach to 154 adult birds of 24 species collected from 11 locations during 2005-2016 to demonstrate the utility of preen gland oil as atool for global monitoring POPs, i.e., PCBs, DDTs, and HCHs. Concentrations of the POPs were higher in the Northern Hemisphere than in the Southern Hemisphere. In particular, ∑20PCBs and∑DDTs were highly concentrated in European shags (Phalacrocorax aristotelis) and Japanese cormorants (Phalacrocorax capillatus), explainable by a diet of benthic fishes. Higher concentrations of γ-HCH were detected in species from the polar regions, possibly reflecting the recent exposure and global distillation of ∑HCHs. We examined the relationship between age and POP concentrations in preen gland oil from 20 male European shags, aged 3-16years old. Concentrations and compositions of POPs were not related to age. We also examined sex differences in the POP concentrations from 24 streaked shearwaters (Calonectris leucomelas) and did not detect a sex bias. These results underline the importance of the geographic concentration patterns and the dietary behavior as determinants species-specific POPs concentrations in preen gland oil.

Legacy and emerging organohalogenated contaminants in wild edible aquatic organisms: Implications for bioaccumulation and human exposure

Highly industrialized and urbanized watersheds may receive various contaminants from anthropogenic activities. In this study, legacy and emerging organohalogenated contaminants (OHCs) were measured in edible wild aquatic organisms sampled from the Pearl River and Dongjiang River in a representative industrial and urban region in China. High concentrations of target contaminants were observed. The Pearl River exhibited higher concentrations of OHCs than the Dongjiang River due to high industrialization and urbanization. Agrochemical inputs remained an important source of OHCs in industrialized and urbanized watershed in China, but vigilance is needed for recent inputs of polychlorinated biphenyls (PCBs) originated from e-waste recycling activities. Bioaccumulation of dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), PCBs, polybrominated diphenyl ethers (PBDEs), and Dechlorane Plus (DP) was biological species- and compound-specific, which can be largely attributed to metabolic capability for xenobiotics. No health risk was related to the daily intake of DDTs, HCHs, and PBDEs via consumption of wild edible species investigated for local residents. However, the current exposure to PCBs through consuming fish is of potential health concern.

Dynamics of persistent organic pollutants in obese adolescents during weight loss

We have investigated the dynamics of various persistent organic pollutants (POPs) in the serum of 94 obese adolescents (34 boys and 60 girls: age range 11–19years) before (0M) and after 5months (5M) of undergoing weight loss treatment. Six groups of POPs, such as polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), chlordane compounds (CHLs), hexachlorocyclohexane isomers (HCHs), hexachlorobenzene (HCB) and polybrominated diphenyl ethers (PBDEs), were detected in all samples in the decreasing order of median levels: DDTs>PCBs>HCB>HCHs>CHLs>PBDEs. Levels and patterns of POPs between boys and girls at two time-points were similar. DDTs (0M/5M; median: 31/42ng/g lw) and PCBs (0M/5M; median: 17/28ng/g lw) were the major POPs. PCB 153 (0M/5M; 33/34% of the sum PCBs) was the most dominant PCB congener, followed by PCB 138 (0M/5M; 31/31%) and PCB 180 (0M/5M; 13/12%), respectively. The most important PBDE congeners were BDE 47 and 153, although total PBDE levels were low and ranged between 0.63 and 0.88ng/g lw. In general, levels of POPs in the obese adolescents were lower than previously reported in Belgian adolescents and adults. Due to weight loss, serum levels (except PBDEs) increased significantly thereafter combined with a body weight decrease (from 4 to 42kg). Serum concentrations increased by 1–3.5% per kilogram weight loss and 1–2.5% per BMI z-score loss for most POPs. To our knowledge, this is the first report on the dynamics of POPs in obese adolescents during weight loss. Lipid-soluble contaminants were released from adipose tissue into the blood leading to redistribution into the body. Whether the increase in the internal exposure to POPs may adversely influence health remains to be determined.

Persistent organic pollutants in red-crowned cranes (Grus japonensis) from Hokkaido, Japan

The red-crowned crane (Grus japonensis) from eastern Hokkaido is classified as a Special Natural Monument in Japan. In this study, we determined the concentrations of persistent organic pollutants (POPs) in red-crowned crane muscle tissues (n = 47). Polychlorinated biphenyls (PCBs) had the highest median concentration (240ng/g lipid weight), followed by dichlorodiphenyltrichloroethane and its metabolites (DDTs) (150ng/g lipid weight), chlordane-related compounds (CHLs) (36ng/g lipid weight), hexachlorobenzene (HCB) (16ng/g lipid weight), hexachlorocyclohexanes (HCHs) (4.4ng/g lipid weight), polybrominated diphenyl ethers (PBDEs) (1.8ng/g lipid weight), and finally, Mirex (1.5ng/g lipid weight). Additionally, a positive correlation was found among POP concentrations. No sex differences beyond body parameters were observed. Additionally, red-crowned cranes exhibited a high enantiomeric excess of (+)-alpha-HCH, with enantiomer fractions varying from 0.51 to 0.87 (average: 0.69).