An extensive sampling campaign was undertaken to study the levels, isomer profiles and riverine mass discharges of perfluoroalkyl acids (PFAAs) and fluorinated alternatives in 19 Chinese rivers. The levels and homologue profiles of Σ 10 PFAAs varied considerably among the 19 rivers (mean 106; median 16.3, range 8.9−1240 ng/L), indicating the influence of specific point sources. Highly branched isomer profiles of perfluorooctanoic acid (18−25% br-PFOA) in rivers with elevated concentrations (96−352 ng/L) indicate that releases during production of PFOA by electrochemical fluorination and/or its use in fluoropolymer manufacture were the dominant sources to these rivers. The fluorinated alternatives 6:2 fluorotelomer sulfonate (detection frequency 21%, < 0.1−3.1 ng/L) and chlorinated polyfluoroalkyl ether sulfonate F-53B (51%, < 0.56−78.5 ng/L) were also found in some rivers. The total Chinese riverine mass discharges of PFOA (mean 80.9; range 16.8−168 t/y) (including monitoring data from this and other studies) were in good agreement with theoretical PFOA emission estimates (17.3−203 t/y) whereas riverine mass discharges of PFOS (mean 3.6; range 1.9−5.6 t/y) could only account for a minor fraction of theoretically estimated PFOS releases (70 t/y). This study provides empirical evidence that emissions from Chinese point sources likely dominate the global emissions of several legacy PFASs (notably PFOA) and fluorinated alternatives (e.g., F-53B).

No abstract

a b s t r a c tShort chain chlorinated paraffins (SCCPs) have been of considerable concern in recent years due to their high production volumes, environmental persistency and potential for long range atmospheric transport. Vegetation can take up considerable amounts of semivolatile organic compounds from the atmosphere and can act as indicators of local contamination. Paired pine needles and bark were sampled around Beijing during winter and summertime to investigate the distribution of SCCPs in urban areas. Levels in bark samples ranged 5.79e37.5 mg/g on a lipid normalized basis (lw) with a geometric mean (GM) of 16.9 mg/g lw whereas levels were 3.03e40.8 (GM 11.8) mg/g lw for needles. Average congener group abundance profiles showed equal contribution of all four carbon groups (C 10e13 ) in wintertime whereas higher abundances of C 10 and C 11 groups were found during summer. Uptake of SCCPs occurred mainly via kinetically limited gaseous deposition and particle bound deposition in the investigated area.

Emissions of perfluoroalkyl acids (PFAAs) have increased in China over the past decade, but human exposure pathways are poorly understood. Here we analyzed 15 PFAAs in commonly consumed food items and calculated body weight normalized dietary intake rates (estimated dietary intake, EDIs) in an area with ongoing PFAA production (Hubei province; n = 121) and an urbanized coastal area (Zhejiang province; n = 106). Geographical differences in concentrations were primarily observed for perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) in animal food items and short-chain PFAAs in vegetable food items. The average EDI of ∑PFAAs for adults in Hubei (998 ng kg day) was more than 2 orders of magnitude higher than that in Zhejiang (9.03 ng kg day). In Hubei province, the average EDI of PFOS for adults (87 ng kg day) was close to or exceeded advisory guidelines used in other countries indicating health risks for the population from long-term exposure. Yet, PFOS could only account for about 10% of the EDI of ∑PFAAs in the Hubei province, which was dominated by short-chain PFAAs through consumption of vegetables. The large contribution of short-chain PFAAs to the total EDIs in manufacturing areas emphasize the need for improved exposure and hazard assessment tools of these substances.

No abstract

No abstract

A total of 26 alternative and legacy perfluoroalkyl and polyfluoroalkyl substances (PFASs) were investigated in air collected above the Bohai and Yellow Seas during a research cruise between June 28 and July 15, 2016. ∑PFAS concentrations ranged from 70 pg m −3 to 430 pg m −3 (mean 230 ± 100 pg m −3 ). Trifluoroacetic acid (TFA, mean 120 ± 80 pg m −3 ) and 8:2 fluorotelomer alcohol (8:2 FTOH, mean 34 ± 46 pg m −3 ) were the predominating compounds of ionizable PFASs (i-PFASs) and neutral PFASs (n-PFASs), respectively. The contributions of C 4 and C 6 i-PFASs were higher than those of C 8 i-PFASs. Alternative substances, such as chlorinated 6:2 polyfluoroalkyl ether sulfonic acids (Cl-6:2 PFESA, mean 1.6 ± 1.2 pg m −3 ) and diPAPs (mean 1.6 ± 1.3 pg m −3 ), were only detected on the filter. The distribution coefficient of 10:2 FTOH was higher than 8:2 FTOH, which could be explained by the length of the carbon chain. The gas phase dry deposition velocities were simulated, and the values ranged from 0.08 ± 0.12 cm s −1 to 0.85 ± 0.28 cm s −1 . For i-PFASs and diPAPs, the estimated fluxes of the particle phase were higher than those of the gas phase. For n-PFASs and TFA, the gas phase deposition played a key role. The ∑PFASs dry deposition fluxes were 11-290 ng (m 2 d) −1 (mean 72 ± 67 ng (m 2 d) −1 ). The measurement of the concentrations in the gas and particle phases simultaneously provided a more comprehensive understanding of PFAS behaviours in air.

The distribution and fate of polybrominated diphenyl ethers (PBDEs) in a riparian ecosystem nearby a wastewater treatment plant effluent were investigated. Different aqueous and terrestrial samples such as soil, sediment, plants, and invertebrates were collected and analyzed for tri-to heptabrominated PBDEs. Furthermore, the food web structure was elucidated using stable carbon and nitrogen isotopes. The highest PBDE levels were found for sediment-and soil-dwelling invertebrates, such as earthworms (Σ 13 PBDEs 144 ng/g lipid weight), Tubifex tubifex (77 ng/g lw), and scarab larvae (49 ng/g lw). Differences in congener composition profiles among the different matrices show that the environmental distribution and fate of PBDEs in ecosystems can be very complex. Among the analyzed PBDEs in this ecosystem, the tetra-brominated BDE-47 was the dominant PBDE congener and followed by the penta-brominated BDE-99. A potential trend of increasing BDE-47/99 ratio with the increase of δ 15 N was observed for species with similar energy sources (δ 13 C), indicating a higher bioaccumulation potential for BDE-47 in this ecosystem. A significant correlation was also found between PBDEs and polychlorinated biphenyls (PCBs), indicating similar sources and fate between the two compound groups in this area. The biota-soil or biotasediment accumulation factors (BSAFs) were somewhat different among the PBDE congeners and species, but were generally highest for those with log K ow values around 6.5-7.