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The present study examined how climate changes may impact the concentrations of lipophilic organochlorines (OCs) in the blood of fasting High Arctic common eiders (Somateria mollissima) during incubation. Polychlorinated biphenyls (PCBs), 1-dichloro-2,2-bis (p-chlorophenyl) ethylene (p,p'-DDE), hexachlorobenzene (HCB) and four chlordane compounds (oxychlordane, trans-chlordane and trans- and cis-nonachlor) were measured in females at chick hatching (n = 223) over 11 years (2007-2017). Firstly, median HCB and p,p'-DDE concentrations increased ~75 % over the study period, whereas median chlordane concentrations doubled (except for oxychlordane). PCB concentrations, in contrast, remained stable over the study period. Secondly, both body mass and clutch size were negatively associated with OC levels, suggesting that females with high lipid metabolism redistributed more OCs from adipose tissue, and that egg production is an important elimination route for OCs. Thirdly, the direct climate effects were assessed using the mean effective temperature (ET: air temperature and wind speed) during incubation, and we hypothesized that a low ET would increase redistribution of OCs. Contrary to expectation, the ET was positively correlated to most OCs, suggesting that a warmer climate may lead to higher OCs levels, and that the impact of ET may not be direct. Finally, potential indirect impacts were examined using the Arctic Oscillation (AO) in the three preceding winters (AO winter 1 - 3 ) as a proxy for potential long-range transport of OCs, and for local spring climate conditions. In addition, we used chlorophyll a (Chla) as a measure of spring primary production. There were negative associations between AO winter 1 and HCB, trans-chlordane and trans-nonachlor, whereas oxychlordane and cis-chlordane were negatively associated with Chla. This suggests that potential indirect climate effects on eiders were manifested through the food chain and not through increased long-range transport, although these relationships were relatively weak., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Organochlorine pesticides (OCPs) in South Africa have for the most part been banned, except dichlorodiphenyltrichloroethane (DDT) which is still used as malaria vector control. The aim of this study was to determine OCP residues in the aquatic fauna of one of South Africa's most populated areas, Soweto. Risk to human health through OCP exposure via fish consumption was investigated. Clarias gariepinus was chosen as bioindicator because it is an apex predator that is in abundance, but is also a valued food source. Dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and chlordanes (CHLs) were detected in the fish tissue with the DDTs being the most prevalent at all sites. Of the three locations, Fleurhof, Orlando, and Lenasia, the latter location's fish had the highest ΣOCP load, ranging between 81 and 1190 ng/g wm. The DDTs were determined to be from historic use, whereas the CHL levels indicated more recent inputs. Although the possibility of illegal use cannot be excluded completely, the presence of OCPs outside of their allowed areas of use indicate that these compounds not only stay in the aquatic systems long term, but may be of concern in areas previously not considered high risk areas. The OCP residues in C . gariepinus from the study area pose an extremely high risk to human health when consumed, and has a cancer risk as high as 1 in 10. This potential problem should be kept in consideration when developing national health and conservation strategies. [ABSTRACT FROM AUTHOR]

The study reports fortnightly atmospheric concentrations of organochlorine pesticides concomitantly measured at an urban, “industrial” and a remote location over a twelve month period in Kuwait to examine seasonal variability and urban-rural concentration gradients. The average ± SD (and range) of the ΣOC concentrations measured throughout the study period in decreasing order were urban, 505 ± 305 (range, 33–1352) pg m − 3 , remote, 204 ± 124 (4.5–556) pg m − 3 , and “industrial” 155 ± 103 (8.8–533) pg m − 3 . The concentrations of most OCs measured in this study, except for DDT and its metabolites, were higher at urban locations relative to their concentrations at remote location, in line with the literature on POPs regarding urban conurbations being sources of industrial chemicals. The most abundant pesticides measured throughout this study were dieldrin, pentachlorobenzene, hexachlorobenzene, ΣDDTs, ΣHCHs, and oxychlordane. Hexachlorobenzene concentrations were generally higher than those of pentachlorobenzene and are both strongly negatively correlated with temperature ( p < 0.05) at all sampling locations. Mean summertime concentrations were higher for hexachlorocyclohexanes, chlordanes, dieldrin, and DDT isomers, except for pp-DDT. This may suggest that concentrations of these compounds may be driven by temperature. [ABSTRACT FROM AUTHOR]

The sources and depositional history of OCPs (organochlorine pesticides), PCBs (polychlorinated biphenyls) and PAHs (polycyclic aromatic hydrocarbons) over the last 100 years were determined in two sediment cores collected in the Amazon region. It was possible to distinguish two depositional periods along the cores. The first period occurred before extensive anthropogenic effects were registered in the sediments. During this time interval, the concentrations of all OCPs and PCBs were below the detection limits (DL), and the PAH concentrations were low and essentially constant (58.19–124.28 ng g − 1 ). The second period starts in the mid-1960s and reflects the increased human influence in the area. The concentrations of OCPs, PCBs, and PAHs increased towards the top of the cores, varying between < DL to 72.67 ng g − 1 , < DL to 0.87 ng g − 1 and 331 to 2341 ng g − 1 , respectively. In general, OCP results showed trends corresponding to the production, usage and prohibition periods of POPs in Brazil. Compounds related to wood treatment, such HCHs and chlordanes, were predominant among the OCPs, which may be associated with many sawmills located in this region. The increase in PAH concentration after the 1960s is mainly due to forest fires, caused by the implementation of large-scale cattle ranches, which burned forests to create pastures. The background PAH concentrations before the 1960s are probably related to natural diagenetic processes. [ABSTRACT FROM AUTHOR]

Urban watersheds are significantly anthropogenically-altered landscapes. Most previous studies cover relatively short periods, without addressing concentrations, loads, and yields in relation to annual climate fluctuations, and datasets on Ag, Se, PBDEs, and PCDD/Fs are rare. Intensive storm-focused sampling and continuous turbidity monitoring were employed to quantify pollution at two locations in the Guadalupe River (California, USA). At a downstream location, we determined loads of suspended sediment (SS) for 14 yrs., mercury (HgT), PCBs, and total organic carbon (TOC) (8 yrs), total methylmercury (MeHgT) (6 yrs), nutrients, and trace elements including Ag and Se (3 yrs), DDTs, chlordanes, dieldrin, and PBDEs (2 yrs), and PCDD/Fs (1 yr). At an upstream location, we determined loads of SS for 4 yrs. and HgT, MeHgT, PCBs and PCDD/Fs for 1 yr. These data were compared to previous studies, climatically adjusted, and used to critically assess the use of small datasets for estimating annual average conditions. Concentrations and yields in the Guadalupe River appear to be atypical for total phosphorus, DDTs, dieldrin, HgT, MeHgT, Cr, Ni, and possibly Se due to local conditions. Other pollutants appear to be similar to other urban systems. On average, wet season flow varied by 6.5-fold and flow-weighted mean (FWM) concentrations varied 4.4-fold, with an average 7.1-fold difference between minimum and maximum annual loads. Loads for an average runoff year for each pollutant were usually less than the best estimate of long-term average. The arithmetic average of multiple years of load data or a FWM concentration combined with mean annual flow was also usually below the best estimate of long-term average load. Mean annual loads using sampled years were also less than the best estimate of long-term average by a mean of 2.2-fold. Climatic adjustment techniques are needed for computing estimates of long-term average annual loads. [ABSTRACT FROM AUTHOR]

Because of mountain cold-trapping, the soil in the Tibetan Plateau may be an important global sink of organochlorine pesticides (OCPs). However, there are limited data on OCPs in the soils of the Tibetan Plateau. In addition, the atmospheric transport and deposition mechanisms of OCPs also need to be further studied. In this study, the sampling area covered most regions of the Tibetan Plateau. The detection frequencies of ΣChlordane (sum of trans -chlordane, cis -chlordane and oxychlordane), HCB, ΣNonachlor (sum of trans - and cis -nonachlor), DDTs, ΣEndo (sum of endosulfan-I, endosulfan-II and endosulfate), aldrin, HCHs, ΣHeptachlor (sum of heptachlor and heptachlor epoxide), mirex and dieldrin were 100%, 98.3%, 96.6%, 94.8%, 89.7%, 87.9%, 62.1%, 55.2%, 32.8% and 6.9%, respectively. DDTs (with arithmetic mean values of 1050 ng kg − 1 dw) and HCHs (393 ng kg − 1 ) were the principal OCPs in cultivated soils, whereas ΣEndo (192 ng kg − 1 ) and ΣChlordane (152 ng kg − 1 ) were the principal OCPs in non-cultivated soils. Local use of DDTs, dicofol and HCHs may be an important source of OCP accumulation in the soil of the Tibetan Plateau. Aldrin and endosulfan are considered to be good indicators for studying atmospheric transport and deposition of OCPs from South Asia and Southeast Asia. Two zones with high OCP levels were found in the southeast and northwest of the Tibetan Plateau. The zones have dissimilar pollution sources of OCPs and are influenced by different factors that affect their precipitation scavenging efficiency. The amount of precipitation was the dominant factor in the southeast, whereas large differences in temperature and wind speed were the dominant factors in the northwest. [ABSTRACT FROM AUTHOR]

To assess how climate-sensitive factors may affect the exposure to organochlorines (OCs) and perfluoroalkyl substances (PFASs), we monitored concentrations in eggs of the common goldeneye (Bucephala clangula) over two decades (1999-2019) in central Norway. The goldeneye alternates between marine and freshwater habitats and is sensitive to climate variation, especially due to alterations in ice conditions which may affect feeding conditions. We assessed how biological factors such as diet (stable isotopes δ 13 C and δ 15 N), the onset of egg laying, and physical characteristics such as winter climate (North Atlantic Oscillation: NAO w ) influenced exposure. We predicted compounds to show different temporal trends depending on whether they were still in production (i.e. some PFASs) or have been banned (i.e. legacy OCs and some PFASs). Therefore, we controlled for potential temporal trends in all analyses. There were declining trends for α- and γ-hexachlorocyclohexane (HCH), oxychlordane, cis-chlordane, cis-nonachlor, p,p'-dichlorodiphenyltrichloroethane (p.p'-DDT) and less persistent polychlorinated biphenyl (PCB) congeners (e.g. PCB101). In contrast, the dominant compounds, such as p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) and persistent PCB congeners, were stable, whereas hexachlorobenzene (HCB) increased over time. Most OCs were positively related to δ 15 N, suggesting higher exposure in birds feeding at upper trophic levels. Chlordanes and HCB were positively associated with δ 13 C, indicating traces of marine input for these compounds, whereas the relationships to most PCBs were negative. Among PFASs, perfluorooctanesulfonamide (PFOSA) and perfluorohexane sulfonic acid (PFHxS) declined. Most PFASs were positively associated with δ 13 C, whereas there were no associations with δ 15 N. Egg laying date was positively associated to perfluoroheptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), suggesting that some of the PFAS load originated from the wintering locations. Although NAOw had little impact on the exposure to organohalogenated contaminants, factors sensitive to climate change, especially diet, were associated with the exposure to OHCs in goldeneyes., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Abstract: Peregrine falcon eggs were collected in South Greenland between 1986 and 2003 and analysed for 6 congeners of toxaphene and 5 chlordane-related pesticides (cis-chlordane, trans-chlordane, cis-nonachlor, trans-nonachlor and oxychlordane). Oxychlordane had the highest median concentration of 1448ng/g lipid weight (lw) or 79ng/g wet weight (ww) of all compounds. Of the toxaphene congeners, CHB-50 was the predominant congener, with a median concentration of 215ng/g lw (15.5ng/g ww). Chlordane-related concentrations were comparable with results from the USA, but lower than those from Canada and Norway. Toxaphene was considerably higher than in eggs of Norwegian peregrine falcon eggs, possibly reflecting different toxaphene usage in the areas of peregrine falcon migration. Toxaphene information in birds of prey is limited and comparisons with other species indicate differences in concentrations and organochlorine pattern. Temporal trends showed significant log-linear decreases for cis-chlordane and trans-chlordane, but no significant trends for other chlordanes or the toxaphene congeners, probably affected by the large variation between eggs, also of the same bird. Correlations between chlordanes and toxaphene in the Greenland peregrine falcon eggs might suggest similar sources of exposure. [Copyright &y& Elsevier]

Abstract: In blubber of ringed seals (Phoca hispida) from Ulukhaktok, NT, residues of DDT, other organochlorine pesticides, and PCBs declined between 1972 and 2010. The rate of decline varied: concentrations of the DDT-group began to fall after 1981, whereas those of PCBs fell rapidly between 1972 and 1981, and then slowed. Concentrations of cis- and trans-chlordane and of HCB in both sexes, and of cis-nonachlor in males, declined slowly between 1978 and 2010; those of other organochlorine pesticides remained steady. Exponential half-lives of p,p′-DDT and p,p′-DDE in female seals are about 9 and 36y (corresponding to initial declines of 7.8% and 1.9% per year, respectively) and those of PCB congeners from about 20 to 60y (declines of 3.2% to <1.5% per year); the more refractory residues may be detectable for centuries to come. Exploratory PCA of PCB congener distribution identified temporal changes apparently not related to molecular structure. [Copyright &y& Elsevier]

Abstract: Sampling of bed sediment for contamination characterization is often limited by the heterogeneity in sediment properties and distribution. In this study, we explored the use of hydroacoustic measurements to characterize sediment properties and guide sediment sampling in a small lake contaminated by organochlorine pesticides (OCPs) and PCBs. A dual frequency hydroacoustic survey was conducted to characterize sediment properties, distribution, and thickness in McGrath Lake, near Ventura, CA. Based upon these results, sediment core samples were collected from 15 sites on the lake, and sectioned into 20cm intervals for sediment characterization and analysis of OCPs and PCBs. Very high concentrations of total DDT and total chlordane were found in the sediments, with mean values of 919 and 34.9ngg−1, respectively. Concentrations of OCPs were highest at 60–80cm depth near the inflow at the north end of the lake. Total PCB concentrations were much lower (mean concentration of 4.5ngg−1). Using the hydroacoustic and chemical data, it was estimated that nearly 30,000m3 of DDT- and chlordane-contaminated sediment (above effects range median values) was present in the uppermost 1.2m of sediment in the lake. A hydroacoustic survey can be a valuable tool used to delineate sediment distribution in a lake, identify areas with deeper organic sediment where hydrophobic contaminants would likely be found, and guide sampling. Sampling and chemical analyses are nonetheless needed to quantify contaminant levels in bottom sediments. When combined with hydroacoustic measurements, this approach can reasonably estimate the distributions and volumes of contaminated sediment important in the development of remediation strategies. [Copyright &y& Elsevier]

Abstract: The aim of this work was to determine the concentrations of organochlorine pesticides (OCPs) and polycyclic aromatic hydrocarbons (PAHs) in topsoils (n=17) at two sampling depths in Southeastern Romania, including industrial (Galati iron and steel plant) and agricultural sites in Galati and Braila counties, as well as nature reserves such as Lower Prut Meadow (Galati County) and Bugeac Lake (Constanta County), and to compare them with national guidelines and values reported for other regions. The total detectable OCP concentrations vary in the ranges 58–1662ngg−1 dry weight (dw) for 0–5cm depth and 6–12,644ngg−1 dw for 5–20cm depth. Of these, the concentrations of HCHs, DDTs, and heptachlor varied in the ranges 6–6818ngg−1, 27–5826ngg−1, and 108–873ngg−1 dw, respectively, the highest values being registered near a cultivated area, located in the proximity of Siret River and Galati town, probably due to extensive use of pesticides in the past. Chlordane was detected only at one industrial site in Galati (53ngg−1 dw), while the levels of aldrin, dieldrin, endrin and mirex were below the detection limits in all the locations and for both depths. The total PAH concentrations for 5–20cm depth range from 9ngg−1 (Lower Prut Meadow) to 25,352ngg−1 dw (cattle farm), being lower than those reported for the upper 5cm layer. The PAH distribution pattern in this study is in agreement with that previously obtained for surface soils from Lower Prut Meadow (prevalence of 3‐ring PAHs), industrial area and farmland (prevalence of 4‐ and 5‐ring PAHs), their sources being industrial activity, traffic and agricultural waste burning. Carcinogenic PAHs contribute 44.8–56.4% for 5–20cm and 43.7–55.8% for 0–5cm depth to total PAHs. In some locations the HCH, DDT and PAH amounts exceed the legal values. [Copyright &y& Elsevier]

Abstract: Persistent organic pollutants have been associated with disease susceptibility and decreased immunity in marine mammals. Concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), chlordanes (CHLDs), and hexachlorocyclohexane isomers (HCHs) were evaluated in terms of stage of development and likely exposure routes (in utero, suckling, fasting) in the blubber of 202 stranded and wild-caught, primarily young of the year (n=177), harbor seals (Phoca vitulina) in the central California coast. This is the first report of HCH concentrations in the blubber of California seals. Lipid normalized concentrations ranged from 200 to 330,000ng/g for sum PCBs, 320–1,500,000ng/g for sum DDTs, 23–63,000ng/g for sum PBDEs, 29–29,000ng/g for sum CHLDs, and 2–780ng/g for sum HCHs. The highest concentrations were observed in harbor seal pups that suckled in the wild and then lost mass during the post-weaning fast. Among the pups sampled in the wild and those released from rehabilitation, there were no differences in mass, blubber depth, or percent lipid although contaminant concentrations were significantly higher in the pups which nursed in the wild. When geographic differences were evaluated in a subset of newborn animals collected near their birth locations, the ratio of sum DDTs to sum PCBs was significantly greater in samples from an area with agricultural inputs (Monterey), than one with industrial inputs (San Francisco Bay). A principal components analysis distinguished between seals from San Francisco Bay and Monterey Bay based on specific PCB and PBDE congeners and DDT metabolites. These data illustrate the important influence of life stage, nutritional status, and location on blubber contaminant levels, and thus the need to consider these factors when interpreting single sample measurements in marine mammals. [Copyright &y& Elsevier]

Abstract: In the European North Sea, harbour porpoises are top predators with relatively long life spans and a limited capacity for metabolic biotransformation of contaminants compared to some other marine mammal species. As such, they are exposed to a mixture of persistent pollutants, such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), DDT and metabolites (DDXs), hexachlorobenzene (HCB) and chlordanes (CHLs) that bioaccumulate in their tissues. We report here on the levels of persistent organic pollutants and of the naturally-produced methoxylated PBDEs (MeO-PBDEs) in blubber, liver and kidney of harbour porpoise neonates (n=3), calves (n=15), juveniles (n=6) and adults (n=4) of the southern North Sea. Concentrations of almost all contaminant classes decrease slightly in all age groups over the period 1990–2008. For some classes (e.g. PCBs and DDXs) however, levels seem to increase little in harbour porpoise calves. In all animals, blubber had the highest concentrations, followed by liver and kidney, whereas liver and kidney were the preferred tissues for several compounds, such as octa- and deca-PCBs. Our data suggest that harbour porpoises calves are exposed to higher or comparable concentrations of POPs and of MeO-PBDEs and somewhat different patterns of selected POPs than adults, potentially placing them, and the entire population, at a disproportionate risk for exposure-related health effects. [Copyright &y& Elsevier]

Abstract: Background: Persistent organic pollutants (POPs) are lipophilic chemicals that bioaccumulate. Most of them were resticted or banned in the 1970s and 1980s to protect human health and the environment. The main source for humans is dietary intake of dairy products, meat and fish. Little data exist on changes of the concentration of POPs in the Swedish population over time. Objective: To study if the concentrations of polychlorinated biphenyls (PCBs), DDE, hexachlorobenzene (HCB) and chlordanes have changed in the Swedish population during 1993–2007, and certain factors that may influence the concentrations. Methods: During 1993–2007 samples from 537 controls in different human cancer studies were collected and analysed. Background information such as body mass index, breast-feeding and parity was assessed by questionaires. Wilcoxon rank-sum test was used to analyse the explanatory factors specimen (blood or adipose tissue), gender, BMI, total breast-feeding and parity in relation to POPs. Time trends for POPs were analysed using linear regression analysis, adjusted for specimen, gender, BMI and age. Results: The concentration decreased for all POPs during 1993−2007. The annual change was statistically significant for the sum of PCBs −7.2%, HCB −8.8%, DDE −13.5% and the sum of chlordanes −10.3%. BMI and age were determinants of the concentrations. Cumulative breast-feeding >8months gave statistically significantly lower concentrations for the sum of PCBs, DDE and the sum of chlordanes. Parity with >2 children yielded statistically significantly lower sum of PCBs. Conclusions: All the studied POPs decreased during the time period, probably due to restrictions of their use. [ABSTRACT FROM AUTHOR]

Abstract: Year-round bulk air deposition samples were collected at 15 sites in the Pearl River Delta (PRD) on a bimonthly basis from Dec 2003 to Nov 2004, and the particle-phase deposition of BDE-209, PAHs, DDTs and chlordane was measured. The annual deposition fluxes of BDE-209, total PAHs (15 compounds), total DDT (sum of p,p′-DDE, p,p′-DDD, p,p′-DDT, and o,p′-DDT ), and chlordane (sum of trans-chlordane and cis-chlordane) varied from 32.6 to 1970μgm−2 yr−1, 22 to 290μgm−2 yr−1, 0.8 to 11μgm−2 yr−1, and 0.25 to 1.9μgm−2 yr−1, respectively. Spatial variations were higher in the centre of the PRD and lower at the coastal sites for all compounds. The seasonal variations of deposition were found to be compound-dependent, influenced by a number of factors, such as the timing of source input, temperature, and precipitation etc. In particular, source input time affected the deposition fluxes of BDE-209 and high-weight PAHs, while temperature-dependent gas–particle partitioning was a key factor for DDT and light-weight PAH deposition. During the whole sampling period, the atmospheric deposition of BDE-209, ΣPAHs, ΣDDTs, and chlordane onto Hong Kong reached about 93, 86, 2.1 and 2.1kgyr−1, respectively, and onto the PRD reached about 13,400, 2950, 82, and 63kgyr−1. By comparing the calculated total air deposition with the burden in the soils, the half residual time of BDE-209 in soils was estimated to be 3years. [Copyright &y& Elsevier]

Abstract: Spatial, temporal, and sediment-type trends in enantiomer signatures were evaluated for cis- and trans-chlordane (CC, TC) in archived core, suspended, and surficial-sediment samples from six lake, reservoir, and river sites across the United States. The enantiomer fractions (EFs) measured in these samples are in good agreement with those reported for sediment, soil, and air samples in previous studies. The chlordane EFs were generally close to the racemic value of 0.5, with CC values ranging from 0.493 to 0.527 (usually >0.5) and TC values from 0.463 to 0.53 (usually <0.5). EF changes with core depth were detected for TC and CC in some cores, with the most non-racemic values near the top of the core. Surficial and suspended sediments generally have EF values similar to the top core layers but are often more non-racemic, indicating that enantioselective degradation is occurring before soils are eroded and deposited into bottom sediments. We hypothesize that rapid losses (desorption or degradation) from suspended sediments of the more bioavailable chlordane fraction during transport and initial deposition could explain the apparent shift to more racemic EF values in surficial and top core sediments. Near racemic CC and TC in the core profiles suggest minimal alteration of chlordane from biotic degradation, unless it is via non-enantioselective processes. EF values for the heptachlor degradate, heptachlor epoxide (HEPX), determined in surficial sediments from one location only were always non-racemic (EF≈0.66), were indicative of substantial biotic processing, and followed reported EF trends. [Copyright &y& Elsevier]

Abstract: The level of polychlorinated biphenyls (PCB) and persistent organochlorinated pesticides (OC) in home-produced eggs was investigated in Belgium. The concentration of dichlorodiphenytrichloroethane (DDT) is above the norm for 17% of the eggs collected during the spring on 58 different locations. For PCB, aldrin, dieldrin, and chlordane, 3–5% of the samples are above the norm too. These levels are surprisingly high for compounds banned for about 30 years. Higher concentrations in home-produced eggs are expected compared to battery eggs because of contact with the environment and especially the soil. For ten selected locations, the concentration in soils, excreta and feed was measured, but no simple correlation between egg and feed or soil level could be established. Hexachlorohexane, endosulfan, endrin, methoxychlor and nitrofen were not detected in any sample. [Copyright &y& Elsevier]

Blubber samples were analyzed for anthropogenic and natural persistent organohalogens in nine killer whales (Orcinus orca) stranded on the northern coast of Japan in 2005. Anthropogenic organohalogens were dominated by DDTs (40–240 µg/g lipid weight (lw)), PCBs (19–68 µg/g lw), and chlordanes (trans-nonachlor, 15–80 µg/g lw). Polybrominated diphenyl ethers (PBDEs) were detected at a range of 0.22–0.64 µg/g lw (BDE-47, 42–74% of ΣPBDE). For natural organohalogens, mixed halogenated dimethylbipyrroles (Br4Cl2-DBP, 6.4–26 µg/g lw), heptachlorinated methylbipyrrole (Cl7-MBP, 0.5–1.9 µg/g lw), two methoxylated tetrabromodiphenyl ethers (6-MeO-BDE47, 0.11–0.58 µg/g lw; 2''-MeO-BDE68, 0.02–0.06 µg/g lw), and dimethoxylated tetrabromobiphenyl (2,2''-diMeO-BB80, 0.06–0.20 µg/g lw) were present. These concentrations in the blubber were higher in calves than in lactating females, indicating that large quantities of the persistent organohalogens transferred from the mother to the calf through lactation. The mother-to-calf transfer ratios of PCBs and PBDEs were significantly decreased with increasing number of halogen substituents, suggesting that higher halogenated congeners are less transferable. [Copyright &y& Elsevier]

Abstract: Human exposure to indoor dust enriched with endocrine-disrupting chemicals released from numerous indoor sources has been a focus of increasing concern. Longer residence times and elevated contaminant concentrations in the indoor environment may increase chances of exposure to these contaminants by 1000-fold compared to outdoor exposure. To investigate the occurrence of semi-volatile endocrine-disrupting chemicals, including PBDEs (polybrominated diphenyl ethers), PCBs (polychlorinated biphenyls), phthalates, pyrethroids, DDT (dichlorodiphenyltrichloroethane) and its metabolites, and chlordanes, indoor dust samples were collected from household vacuum cleaner bags provided by 10 apartments and 1 community hall in Davis, California, USA. Chemical analyses show that all indoor dust samples are highly contaminated by target analytes measured in the present study. Di-(2-ethylhexyl)phthalate was the most abundant (104–7630 µg/g) in all samples and higher than other target analytes by 2 to 6 orders of magnitude. PBDEs were also found at high concentrations (1780–25,200 ng/g). Although the use of PCBs has been banned or restricted for decades, some samples had PCBs at levels that are considered to be concerns for human health, indicating that the potential risk posed by PCBs still remains high in the indoor environment, probably due to a lack of dissipation processes and continuous release from the sources. Although the use of some PBDEs is being phased out in some parts of the U.S., this trend may apply to PBDEs as well. We can anticipate that exposure to PBDEs will continue as long as the general public keeps using existing household items such as sofas, mattresses, and carpets that contain PBDEs. This study provides additional information that indoor dust is highly contaminated by persistent and endocrine-disrupting chemicals. [Copyright &y& Elsevier]