Identifying dermal exposure as the dominant pathway of children's exposure to flame retardants in kindergartens.

Exploration of multiple sources of brominated (BFRs) and organophosphate flame retardants (OPFRs) for children promotes the understanding of exposure pathways and health risk. 10 BFRs and 9 OPFRs were measured in skin wipes from hands, forehead, and arms of 30 children, and surface wipe samples from sills, toys, desks and floors, and indoor air samples of kindergartens from Xinxiang, China. Higher ∑9OPFRs concentrations were observed in the forehead (1840 ng/m2), followed by hand (1420 ng/m2) and arm wipes (1130 ng/m2), and the ∑8BFRs concentrations in forehead, hand and arm wipes were 116, 315 and 165 ng/m2, respectively. The total concentration of OPFRs and BFRs in floor wipes (66.1 and 24.5 ng/m2) were lower than those in toy (205 and 535 ng/m2), sill (227 and 30.1 ng/m2) and desk (84.4 and 139 ng/m2) wipes. Concentrations of FRs in forehead wipes were significantly correlated with those in gaseous air (p < 0.05), moderate correlations were found between the hand wipes and surface wipes (p = 0.054). We estimated the daily average dosages (DADs) of children exposure to FRs via multiple pathways. Compared to DADs via inhalation and hand-to-mouth transfer, dermal exposure was determined to be the predominant exposure pathway to ∑9OPFRs and ∑8BFRs.

Lifetime bioaccumulation, gender difference, tissue distribution, and parental transfer of organophosphorus plastic additives in freshwater fish.

Plastic pollution has been a growing global issue. Various plastic additives may enter the environment with plastic debris, which could also become contaminants. Lifetime bioaccumulation, gender difference, tissue distribution, and parental transfer potential of commonly applied organophosphorus plastic additives (OPPAs) were investigated in wildlife fish of the Pearl River system, China. The OPPAs were widely detected in 7 consumable fish species. Tris (2-chloropropyl) phosphate was the predominant compound, with a median concentration of 18.8 ng/g lipid weight. The total OPPA concentrations (ΣOPPAs) were higher in the livers and swimming bladders, suggesting important roles of lipophilicity on the OPPAs accumulation in the fish. Besides, the livers were more abundant in the non-chlorinated OPPAs relative to the other tissues, indicating potentially stronger metabolism of the chlorinated OPPAs in the livers. Redbelly tilapia contained obviously lower ΣOPPAs than the other species. On the other hand, proportions of the chlorinated OPPAs were obviously lower in barbel chub and Guangdong black bream. For an individual species, higher ΣOPPAs were usually detected in the female than in the male fish. Furthermore, the females contained higher proportions of the non-chlorinated OPPAs. These results suggested potentially more accumulation of the OPPAs, particularly the non-chlorinated OPPAs in the female than in the male fish. Body weight dependence of the OPPAs accumulation showed varied patterns depending on species, tissue, and compound. Species-specific characteristics affected by both ecology and organisms' physiology should be considered in combination in assessing bioaccumulation of the OPPAs. The OPPAs were slightly bioaccumulative with LogBAFs of 1.2-3.3. The OPPAs did not show obvious inclination to be partitioned to biota from sediment. Omnipresence of the OPPAs in both egg/ovary and testis of the fish suggested potential transgenerational transfer of these chemicals, which can be a serious ecological issue and warrants further research.

Distribution, sedimentary record, and persistence of microplastics in the Pearl River catchment, China.

Microplastics (MPs) in the environment have become an issue worldwide. However, data about MPs in freshwater systems are still limited so far. This study investigated sources, fate, and seasonal and spatial distribution of MPs in the main stream Pearl River and its tributaries, as well as in the Pearl River Estuary (PRE), China. MPs were widely detected in the river water, river bed sediment, and estuarine sediment, with abundances of 0.57 ±â€¯0.71 items L-1, 685 ±â€¯342 items kg-1 dry weight (dw), and 258 ±â€¯133 items kg-1 dw, respectively. Sheet, fragmental, and fibrous polyethylene, polypropylene, and ethylene-propylene copolymers were predominant, suggesting that MPs in the Pearl River catchment be mainly derived from fragmentation of discarded plastic wastes. In addition, municipal wastewater was also an important MPs source, especially for polyethylene terephthalate (PET) fibers. Polymers of higher density, such as PET and polyvinyl alcohol were relatively more abundant in the sediment than in the river water, especially in the estuarine sediment. Upward increase of the MP abundance was observed in the sedimentary core, probably indicating increasing release of plastic wastes due to growing production and uses of plastic products. On the other hand, percentage of finer MPs increased with increasing depth. The results revealed persistence and potential downward dispersion of the fine MPs. The MPs abundance was positively related with population density and gross domestic product, demonstrating impacts of human activities and economic development on the MPs contamination. Higher MPs abundance was detected in dry season than in wet season in the river water, suggesting dilution effect of precipitation. It's estimated that 15963 tons of MPs could be released annually into the PRE from the main stream Pearl River and its tributaries.

Occurrence and Species-Specific Distribution of Plastic Debris in Wild Freshwater Fish from the Pearl River Catchment, China.

Freshwater systems are an important source and vector of plastic debris found in oceans. However, plastic debris in freshwater organisms has not been well studied. The occurrence, characterization, polymer composition, and seasonal and spatial distribution of plastic debris were investigated in 9 species of wild freshwater fish from the Pearl River catchment, south China. Approximately 50% of the total fish (n = 279) belonging to 9 species were found to ingest plastic debris with an average abundance of 7.0 ± 23.8 items/individual, indicating wide plastic contamination in the Pearl River catchment. Plastic debris were predominantly transparent or white in color, fibers or fragments in shape, and polyethylene, polypropylene, ethylene-propylene copolymer (PE-PP), and polyethylene terephthalate (PET) in polymer composition. A species-specific distribution of the plastic debris was observed in terms of abundance, shape, and polymer composition. Redbelly tilapia had the highest (27.4 ± 54.0 items/individual), whereas common carp had the lowest (0.2 ± 0.4 items/individual) abundance of the plastic debris in their gastrointestinal tracts. Fibers of PET were predominant in the freshwater species except in barbel chubs, which had mostly PE-PP fragments. Omnivores and bottom-dwellers were more likely to ingest plastic debris. Seasonal variation was observed, with generally higher abundance of plastic debris in fish collected in the dry season than in the wet season. Environ Toxicol Chem 2019;38:1504-1513. © 2019 SETAC.