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Brominated flame retardants (BFRs) such as tetrabromobisphenol A (TBBPA) and hexabromocyclododecanes (HBCDs) are of ecological concern due to their ubiquitous presence and adverse effects. There is a paucity of data on environmental fate of such compounds in mangrove wetlands, which are unique ecosystems in coastal intertidal areas and act as natural sinks for many pollutants. In this study, mangrove plants and sediments were collected from an urban nature reserve in South China to investigate bioaccumulation and translocation of TBBPA and HBCDs. The mean (range) concentrations of TBBPA and ΣHBCD in roots, stems and leaves were 67 (

Biomass fuels remain main energy sources in many remote rural regions, but potential health hazards from exposure to biomass combustion fumes have not been adequately assessed. Combustion of biomass fuels generates abundant polycyclic aromatic hydrocarbons (PAHs); hence residential exposure to PAHs can be used to evaluate the potential health risk to remote rural populations. The present study selected rural Tibetans to address the above-mentioned issue. Samples of indoor air and dust, human urine and local foods (Tsampa flour and buttered tea) were collected from five rural households in Langkazi County, an agricultural and pasturing region in Tibet of China in the summer season, which represented the best-case scenario as no heating was required. Residential exposure to PAHs by adults amounted to benzo[a]pyrene equivalent (BaPeq) dosages of 110–760, 1.2–50 and 0.5–23 ng d−1 for ingestion, inhalation and dermal contact, respectively. Daily intakes of naphthalene, fluorene, phenanthrene and pyrene estimated from urinary monohydroxy PAH metabolites and from diet and inhalation exposure to PAHs were comparable (3.9, 1.9, 12 and 3.3 μg d−1 versus 9.5, 2.5, 5.1 and 1.1 μg d−1), indicating the utility of external exposure in assessing daily intake of PAHs. The median incremental lifetime cancer risk was 32 × 10−6 (95% confidence interval: 0.7–73 × 10−6) for ingestion and 2.4 × 10−6 (95% confidence interval: 0.02–12 × 10−6) for inhalation and dermal contact combined, indicating moderate to slight potential cancer risk. Diet is the dominant source of health hazards for rural Tibetans, but cooking fumes also present a meaningful concern. The present study demonstrates that the pristine lifestyles of remote rural residents may be of global health concern, and merit further investigations. Keywords: Biomass fuel, Rural Tibet, Polycyclic aromatic hydrocarbons, Health risk, Life style

There is a wide concern that emerging organic pollutants (EOPs) in surface water could adversely affect human health and wildlife. However, the geographic distribution, exposure pattern and ecological risk of emerging organic pollutants are poorly understood at a global scale. This paper provides a comprehensive survey on the exposure level of EOPs in China, the US and the EU based on the published literature. The hazard level of three categories of EOPs, namely pharmaceuticals and personal care products (PPCPs), pesticides and industrial chemicals was further evaluated by adopting a novel Aquatic HazPi index that jointly accounts for the persistence, bioaccumulation, toxicity and bioactivity. Furthermore, a correlation analysis of land use with the surface water exposure status regarding the synthetic chemicals was conducted. According to the published data reported between 2010 and 2016, the concentration of pesticides in the US was higher than in the EU and China. The concentration of PPCPs in the EU was generally lower than in both the US and China, while the concentration of industrial chemicals in China was higher than in the EU and the US. Among the chemicals whose median concentration in surface water was >10 ng/L, the antiretroviral Efavirenz, the pesticide Fipronil, and octocrylene, an industrial chemical and cosmetic ingredient, were found with the highest aquatic HazPi value. Lastly, the spatial distribution and concentration of hazardous EOPs was shown to depend on local landscape and land usages. Our study provides the first broad overview on the geographic distribution, exposure pattern of hazardous EOPs in the three major economic entities: China, the US and the EU. Keywords: Chemical pollution, Risk assessment, Pesticide, Industry, Pharmaceutical and personal care products, Land use

Poly- and perfluoroalkyl substances (PFASs) are important environmental contaminants globally and in the early 2000s they were shown to be ubiquitous contaminants in Arctic wildlife. Previous reviews by Butt et al. and Letcher et al. have covered studies on levels and trends of PFASs in the Arctic that were available to 2009. The purpose of this review is to focus on more recent work, generally published between 2009 and 2018, with emphasis on PFASs of emerging concern such as perfluoroalkyl carboxylates (PFCAs) and short-chain perfluoroalkyl sulfonates (PFSAs) and their precursors. Atmospheric measurements over the period 2006–2014 have shown that fluorotelomer alcohols (FTOHs) as well as perfluorobutanoic acid (PFBA) and perfluoroctanoic acid (PFOA) are the most prominent PFASs in the arctic atmosphere, all with increasing concentrations at Alert although PFOA concentrations declined at the Zeppelin Station (Svalbard). Results from ice cores show generally increasing deposition of PFCAs on the Devon Ice cap in the Canadian arctic while declining fluxes were found in a glacier on Svalbard. An extensive dataset exists for long-term trends of long-chain PFCAs that have been reported in Arctic biota with some datasets including archived samples from the 1970s and 1980s. Trends in PFCAs over time vary among the same species across the North American Arctic, East and West Greenland, and Svalbard. Most long term time series show a decline from higher concentrations in the early 2000s. However there have been recent (post 2010) increasing trends of PFCAs in ringed seals in the Canadian Arctic, East Greenland polar bears and in arctic foxes in Svalbard. Annual biological sampling is helping to determine these relatively short term changes. Rising levels of some PFCAs have been explained by continued emissions of long-chain PFCAs and/or their precursors and inflows to the Arctic Ocean, especially from the North Atlantic. While the effectiveness of biological sampling for temporal trends in long-chain PFCAs and PFSAs has been demonstrated, this does not apply to the C4–C8–PFCAs, perfluorobutane sulfonamide (FBSA), or perfluorobutane sulfonate (PFBS) which are generally present at low concentrations in biota. In addition to air sampling, sampling abiotic media such as glacial cores, and annual sampling of lake waters and seawater would appear to be the best approaches for investigating trends in the less bioaccumulative PFASs. Keywords: Perfluoroalkyl substances, PFASs, Perfluoroalkyl carboxylates, Perfluoroalkyl sulfonates, Perfluorobutanoic acid, Perfluorooctanoic acid, Air, Seawater, Ice caps, Biota, Contaminants, Long-range transport, Review

Since the last Arctic Monitoring and Assessment Programme (AMAP) effort to review biological effects of the exposure to organohalogen compounds (OHCs) in Arctic biota, there has been a considerable number of new Arctic effect studies. Here, we provide an update on the state of the knowledge of OHC, and also include mercury, exposure and/or associated effects in key Arctic marine and terrestrial mammal and bird species as well as in fish by reviewing the literature published since the last AMAP assessment in 2010. We aimed at updating the knowledge of how single but also combined health effects are or can be associated to the exposure to single compounds or mixtures of OHCs. We also focussed on assessing both potential individual as well as population health impacts using population-specific exposure data post 2000. We have identified quantifiable effects on vitamin metabolism, immune functioning, thyroid and steroid hormone balances, oxidative stress, tissue pathology, and reproduction. As with the previous assessment, a wealth of documentation is available for biological effects in marine mammals and seabirds, and sentinel species such as the sledge dog and Arctic fox, but information for terrestrial vertebrates and fish remain scarce. While hormones and vitamins are thoroughly studied, oxidative stress, immunotoxic and reproductive effects need further investigation. Depending on the species and population, some OHCs and mercury tissue contaminant burdens post 2000 were observed to be high enough to exceed putative risk threshold levels that have been previously estimated for non-target species or populations outside the Arctic. In this assessment, we made use of risk quotient calculations to summarize the cumulative effects of different OHC classes and mercury for which critical body burdens can be estimated for wildlife across the Arctic. As our ultimate goal is to better predict or estimate the effects of OHCs and mercury in Arctic wildlife at the individual, population and ecosystem level, there remain numerous knowledge gaps on the biological effects of exposure in Arctic biota. These knowledge gaps include the establishment of concentration thresholds for individual compounds as well as for realistic cocktail mixtures that in fact indicate biologically relevant, and not statistically determined, health effects for specific species and subpopulations. Finally, we provide future perspectives on understanding Arctic wildlife health using new in vivo, in vitro, and in silico techniques, and provide case studies on multiple stressors to show that future assessments would benefit from significant efforts to integrate human health, wildlife ecology and retrospective and forecasting aspects into assessing the biological effects of OHC and mercury exposure in Arctic wildlife and fish. © 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Despite the global prevalence of both mercury (Hg) contamination and anthropogenic eutrophication, relatively little is known about the behavior of Hg in eutrophic and hypereutrophic systems or the effects of lake trophic status on Hg uptake and trophodynamics. In the current study we explore Hg trophodynamics at 8 tropical East African study sites ranging from mesotrophic to hypereutrophic, in order to assess the influence of lake trophic status on Hg uptake and biomagnification. Comprehensive water, plankton and fish samples were collected for analysis of total mercury (THg) and stable carbon and nitrogen isotopic ratios. We found evidence that uptake of THg into phytoplankton tended to be lower in higher productivity systems. THg concentrations in fish were generally low, and THg trophic magnification factors (TMFs; representing the average increase in contaminant concentrations from one trophic level to the next) ranged from 1.9 to 5.6. Furthermore TMFs were significantly lower in hypereutrophic lakes than in meso- and eutrophic lakes, and were negatively related to chlorophyll a concentrations both across our study lakes, and across African lakes for which literature data were available. These observations suggest that THg concentrations were strongly influenced by trophic status, with year-round high phytoplankton and fish growth rates reducing the potential for high THg in fish in these productive tropical lakes.