Occurrence, partitioning behavior and risk assessments of per- and polyfluoroalkyl substances in water, sediment and biota from the Dongshan Bay, China.

Twenty-five per- and polyfluoroalkyl substances (PFASs) were analyzed in water, sediment and biota from the Dongshan Bay (DSB) to study their seasonal variations, composition profiles, potential pollution sources, partitioning behavior and risk assessments. The total concentrations of PFASs (∑PFASs) in water ranged from 3.2 to 6.5 ng L−1 (mean 4.0 ng L−1) during the dry season, and 0.11–4.5 ng L−1 (mean 1.3 ng L−1) during the wet season. Perfluoro-butane sulfonic acid (PFBS), perfluoro-butanoic acid (PFBA) and perfluoro-octanoic acid (PFOA) were dominated and frequently detected in water. ∑PFASs in sediment were 0.15–0.37 ng g−1 dw (mean 0.24 ng g−1 dw) with the long-chain PFASs perfluoro-octane sulfonic acid (PFOS) dominating. High concentrations of PFASs in land-based drainage outlets (2.0–384.6 ng L−1 in water) and Zhangjiang estuary indicated that land-based discharges and the river discharge were the main sources. High concentration (366.1 ng L−1) and proportion (94%) of PFBA on one drainage outlet agreed with the trend that PFBA was as an alternative to long-chain PFASs. ∑PFASs in biota ranged from 0.11 to 0.40 ng g−1 ww, and only long-chain PFASs were detected. The partition coefficients (log K d) of PFASs between water and sediment ranged from 1.13 to 2.90, increased with carbon chain length, implied long-chain PFASs are more likely to adsorb to sediment. Results of ecological and health risk assessments indicated that PFASs had no significant risk for the aquatic organisms and local residents. • Short-chain PFASs as alternatives increase in the environment. • Drainage outlets and the river discharge contributed PFASs to the DSB. • Log K d of PFASs increased with the increasing of carbon chain length. [ABSTRACT FROM AUTHOR]