The environmental and human health concerns for organohalogen contaminants (OHCs) extend beyond the 23 persistent organic pollutants (POPs) regulated by the Stockholm Convention. The current, intense ...industrial production and use of chemicals in China and their bioaccumulation makes Chinese wildlife highly suitable for the assessment of legacy, novel and emerging environmental pollutants. In the present study, six species of amphibians, fish and birds were sampled from paddy fields in the Yangtze River Delta (YRD) were screened for OHCs. Some extensive contamination was found, both regarding number and concentrations of the analytes, among the species assessed. High concentrations of chlorinated paraffins were found in the snake, Short-tailed mamushi (range of 200–340μgg−1lw), Peregrine falcon (8–59μgg−1lw) and Asiatic toad (97μgg−1lw). Novel contaminants and patterns were observed; octaCBs to decaCB made up 20% of the total polychlorinated biphenyls (PCBs) content in the samples and new OHCs, substituted with 5–8 chlorines, were found but are not yet structurally confirmed. In addition, Dechlorane 602 (DDC-DBF) and numerous other OHCs (DDTs, hexachlorocyclohexanes (HCHs), polybrominated diphenyl ethers (PBDEs), hexbromocyclododecane (HBCDD), chlordane, heptachlor, endosulfan and Mirex) were found in all species analyzed. These data show extensive chemical contamination of wildlife in the YRD with a suite of OHCs with both known and unknown toxicities, calling for further in-depth studies.
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•Six wildlife species of amphibians, fish and birds were sampled and screened for organohalogen contaminants (OHCs) in a paddy field in Yangtze River Delta, China.•High contaminations of chlorinated paraffins were found particularly in terrestrial species.•A novel pattern of PCBs with relatively high contribution from octa-CBs to decaCB was observed.•A new group of OHCs, with 5–8 chlorines, were found but are not yet structurally confirmed.•DDTs was the major organochlorine pesticide contaminant in wildlife; HBCDD level in wildlife was comparable to PBDEs in the present study.•The results show an extensive contamination of OHCs in wildlife in Yangtze River Delta, calling for further (eco)toxicology study and environmental monitoring.
Abstract
Fine particulate-matter is an important component of air pollution that impacts health and climate, and which delivers anthropogenic contaminants to remote global regions. The complex ...composition of organic molecules in atmospheric particulates is poorly constrained, but has important implications for understanding pollutant sources, climate-aerosol interactions, and health risks of air pollution exposure. Here, comprehensive nontarget high-resolution mass spectrometry was combined with in silico structural prediction to achieve greater molecular-level insight for fine particulate samples (
n
= 40) collected at a remote receptor site in the Maldives during January to April 2018. Spectral database matching identified 0.5% of 60,030 molecular features observed, while a conservative computational workflow enabled structural annotation of 17% of organic structures among the remaining molecular dark matter. Compared to clean air from the southern Indian Ocean, molecular structures from highly-polluted regions were dominated by organic nitrogen compounds, many with computed physicochemical properties of high toxicological and climate relevance. We conclude that combining nontarget analysis with computational mass spectrometry can advance molecular-level understanding of the sources and impacts of polluted air.
Faeces from day 1–5 of orally administered 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) in rat have been analysed for hydroxylated metabolites. Six hydroxylated tetrabrominated diphenyl ethers, as ...well as three hydroxylated tribrominated diphenyl ethers found, were structurally identified. They were 2′-hydroxy-2,4,4′-tribromodiphenyl ether, 3′-hydroxy-2,4,4′-tribromodiphenyl ether, 4′-hydroxy-2,2′,4-tribromodiphenyl ether, 6-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether, 2′-hydroxy-2,3′,4,4′-tetrabromodiphenyl ether, 3-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether, 5-hydroxy-2,2′,4,4′-tetrabromodiphenyl ether, 4′-hydroxy-2,2′,4,5′-tetrabromodiphenyl ether and 4-hydroxy-2,2′,3,4′-tetrabromodiphenyl ether. The analysis was performed using gas chromatography–mass spectrometry (GC–MS). The identification of the hydroxylated polybrominated diphenyl ether (OH-PBDE) metabolites in the rat faeces was supported by similar relative retention times (RRTs) versus 2,2′,3,4,4′,5-hexabromodiphenyl ether (BDE-138) on two columns of different polarities compared to the authentic references. The identification of the OH-PBDE metabolites was also supported by full scan electron ionisation mass spectra. Two of the identified OH-PBDE metabolites have identical structures as natural products, which previously have been isolated from marine sponges and an ascidian.
The application of the recently discovered oxofluoride solid solution (CoxNi1−x)3Sb4O6F6 as a catalyst for water oxidation is demonstrated. The phase exhibits a cubic arrangement of the active metal ...that forms oxo bridges to the metalloid with possible catalytic participation. The Co3Sb4O6F6 compound proved to be capable of catalyzing 2H2O→O2+4H++4e− at 0.33 V electrochemical and ≤0.39 V chemical overpotential with a TOF of 4.4⋅10−3, whereas Ni3Sb4O6F6 needs a higher overpotential. Relatively large crystal cubes (0.3–0.5 mm) are easily synthesized and readily handled as they demonstrate both chemical resistance to wear after repeated in situ tests under experimental conditions, and have a mechanical hardness of 270 V0.1 using Vickers indentation. The combined properties of this compound offer a potential technical advantage for incorporation to a catalytic interface in future sustainable fuel production.
The Co3Sb4O6F6 compound (see figure; Co blue, O red, Sb yellow, F green) of the oxofluoride solid solution (CoxNi1−x)3Sb4O6F6 is proved to be capable of catalyzing the water oxidation reaction with a TOF of 4.4×10−3. Relatively large crystal cubes (0.3–0.5 mm) were easily synthesized and readily handled, and they demonstrated chemical resistance to wear.
Environmental and human exposures to brominated flame retardants (BFR) have been of emerging concern since some BFR are persistent and bioaccumulative compounds. Among those, polybrominated diphenyl ...ethers (PBDE) have frequently been reported in low to high ng/g concentrations in human blood around the world while hexabromocyclododecane (HBCDD) only occasionally has been reported and then in the low ppb concentrations in human blood. The present study concerns PBDE congener and HBCDD concentrations in human milk from Stockholm from 1980 to 2004. HBCDD concentrations has increased four to five times since 1980 until 2002 but seems to have stabilized at this concentration in the last years (2003/04). Similarly, BDE-153 has continued to increase at least to 2001, after which it has stabilized in the mother's milk. Other PBDE congeners with four to five bromine substituents peaked 5 years earlier (1995) and are all decreasing. DecaBDE (BDE-209) is not a suitable biomarker for time trend studies according to the present results, showing no changes over time. This is likely due to its short apparent half-life in humans and poor transfer from blood to milk.
Bioaccumulation of persistent organic compounds can eventually lead to concentrations in wildlife and humans that are deleterious to health. The present paper documents the identification, ...quantification, and synthesis of a novel compound, 2,2‘-dimethoxy-3,3‘,5,5‘-tetrabromobiphenyl (2,2‘-diMeO-BB80), present in the marine mammals Striped dolphin (Stenella coeruleoalba), Bottlenose dolphin (Tursiops truncatus), Minke whale (Balaenoptera acutorostrata), and Baird's beaked whale (Berardius bairdii) caught in the Pacific Ocean. Identification was based on comparison of the relative retention times of the compound on two gas chromatographic columns of different polarities to those of an authentic standard. Furthermore, this identification was also supported by comparison of the full scan mass spectrometric data collected employing electron ionization (EI), positive ion chemical ionization (PICI), and electron capture negative ionization (ECNI). The concentrations of 2,2‘-diMeO-BB80 in the samples ranged from 12 to 800 ng/g lipid, making this consistently one of the most abundant compounds among those analyzed, including polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCDD), and methoxylated PBDEs. The known occurrence of 3,3‘,5,5‘-tetrabromo-2,2‘-biphenyldiol (2,2‘-diOH-BB80) in the marine environment as a natural product suggests that its methylated derivative, 2,2‘-diMeO-BB80, is also of natural origin. To obtain the necessary authentic standards, synthesis was performed of 2,2‘-diMeO-BB80 and the known natural product 2‘,6-dimethoxy-2,3‘,4,5‘-tetrabromodiphenyl ether (2‘,6-diMeO-BDE68).
The observed high-level burdens of organohalogens among the residents of the Faroe Islands, needs to be explained. Long-finned pilot whale (
Globicephala melas) blubber and meat are known sources of ...environmental exposure. The present study focus on the organohalogen contamination of the fulmar (
Fulmarus glacialis). The compounds quantified in fulmar muscle, fat, and egg are PCBs, DDTs, hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). The dominating pollutants are the 4,4′-DDT metabolite 4,4′-DDE and the two PCB congeners, CB-153 and CB-180, which are present in geometric mean concentrations of 7100, 4700 and 2500
ng/g lipid weight (l.w.), respectively, in adult fulmar muscle. 4,4′-DDT and HCB concentrations are approximately 250
ng/g
l.w., each. Concentrations in the eggs are about 50% of the fulmar muscle levels, due to differences in lipid amounts, 4% in muscle and 10% in the eggs, the exposure contribution on a fresh weight basis is almost the same. As a result, both the egg and the adult fulmar muscle may lead to a significant exposure risk, if consumed by humans.
BDE-153, the most abundant PBDE congener in fulmar muscle, with a geometric mean concentration of 6.5
ng/g
l.w., is much lower than the individual PCB congeners and 4,4′-DDE concentrations. In the adult fulmar muscle, the relative PBDE congener pattern is different from that previously observed in biota, with BDE-153 and BDE-154 as the dominating congeners, rather than BDE-47. In contrast, BDE-47 is the most abundant congener in juvenile muscle and subcutaneous fat. The ∑PBDE concentrations are almost the same in egg, muscle (adult and juvenile) and subcutaneous fat (juvenile). For the polybrominated biphenyl (BB-153) the concentrations are considerably higher in the adult bird and egg than in the juvenile bird; this is also seen for the PCB and 4,4′-DDE concentrations.
PCB concentrations found in fulmar egg and muscle are in the same range as seen in the pilot whale, i.e. 590–5700
ng/g
l.w. for CB-153. Hence humans are also exposed to PCBs at a reasonable degree via intake of fulmar and/or fulmar egg and not only via pilot whale blubber.
Chlorinated paraffins (CPs) are high-production volume industrial chemicals consisting of n-alkanes (with 10 to 30 carbon atoms in the chain) with chlorine content from 30 to 70% of weight. In ...Europe, the use of short chain chlorinated paraffins (SCCPs) has been restricted by the Stockholm Convention on POPs due to their PBT (persistent, bioaccumulative and toxic) properties. Medium (MCCPs) and long chain (LCCPs) chlorinated paraffins are used as substitution products. In this work we studied the partitioning behavior of five different CP technical mixtures from the established categories (2 SCCPs, 1 MCCP, 1 LCCP and 1 CP technical mixture covering all categories) using passive dosing, by determining the partitioning coefficient of CP technical mixtures between silicone and water (K silicone‑water) as well as between organic matter and water (K oc‑water). We show that both silicone-water and organic carbon–water partition coefficients overlap between different categories of CP technical mixtures. These results indicate that in-use MCCPs and LCCPs may be equally or more bioaccumulative than restricted SCCPs. For the tested mixtures, both chlorine content and carbon chain length showed a significant correlation with both K silicone‑water and K oc‑water.
While young children are rarely included in biomonitoring studies, they are presumed to be at greater risk of ingesting environmental contaminantsparticularly those that accumulate in foods or shed ...from consumer products. The widely used fire retardants polybrominated diphenyl ethers (PBDEs) are ubiquitous contaminants in the indoor environment and are widely detected at higher levels in Americans than in individuals from other countries. However, there are only three studies of PBDEs in U.S. children. We hypothesized that PBDEs are present in higher concentrations in young children than their mothers. PBDEs were assessed in blood samples collected concurrently from 20 mothers and their children, ages 1.5 to 4 years. The chemical analyses were performed by GC/MS applying selected ion monitoring. The samples were analyzed for 20 PBDE congeners; 11 were detected. ΣPBDEs for children were typically 2.8 times higher than for mothers, with median child:mother ratios varying from 2 to 4 for individual congeners. In 19 of 20 families studied, children had higher ΣPBDE concentrations than their mothers with significant (p < 0.01) concentration differences for five of the PBDE congeners. Decabromodiphenyl ether (BDE-209) was quantitated in 13 children and 9 mothers. Other studies indicate PBDEs are not elevated at birth, suggesting that early life is an intense period of PBDE intake. Children’s increased hand-to-mouth activity, dietary preferences, and exposures from breast milk may result in greater ingestion of PBDEs than adults. These findings suggest that measurements from adults likely do not reflect exposures to young children despite sharing homes and similar diets.
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