Occurrence, Temporal Variation (2010-2018), Distribution, and Source Appointment of Per- and Polyfluoroalkyl Substances (PFAS) in Mollusks from the Bohai Sea, China

Per-and polyfluoroalkyl substances (PFAS) including legacy and emerging compounds have been widely detected in various environmental media and have attracted a significant amount of research and regulatory attention. Aquatic environments such as seawater are important PFAS sinks due to the strong stability and water solubility of PFAS. In this study, the occurrence, temporal variation, and source appointment of 17 legacy and 16 emerging PFAS in seven different mollusks from nine cities around the Bohai Sea, China, were investigated from 2010 to 2018. Significantly higher concentrations of legacy PFAS compared to those of emerging PFAS indicate that legacy PFAS products, including perfluorooctane sulfonic acid and perfluorooctanoic acid, are still widely used in China. However, the decreasing trend of the legacy PFAS concentrations in mollusks after 2015 indicate that these products concentrations in mollusks after 2015 indicate that these products are gradually being withdrawn from the market due to China's implementation of the Stockholm Convention. A positive matrix factorization was used to identify six primary pollution sources including electrochemical fluorination processes, domestic sewage discharge, metal plating, food packaging, the fluorochemical industry, and the fluoropolymer industry. Among these sources, the fluoropolymer industry is the largest contributor to environmental PFAS, accounting for 68% of the total pollution in this region.

Automated summary

Legacy and emerging PFAS have been widely detected in various environmental media, with significantly higher concentrations of legacy PFAS compared to emerging PFAS indicating the continued use of legacy PFAS products in China. The decreasing trend of legacy PFAS concentrations in mollusks after 2015 suggests a gradual withdrawal of these products from the market due to China's implementation of the Stockholm Convention. Positive matrix factorization identified six primary pollution sources, with the fluoropolymer industry being the largest contributor to environmental PFAS pollution in the region, accounting for 68% of the total pollution.