Emissions of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in China fell dramatically between 2016 and 2021, according to a new study that provides the first consecutive, high-resolution multimedia inventory of these persistent organic pollutants across the Chinese mainland. The research, published in Environmental Science and Ecotechnology, shows PFOS emissions dropped by about 89% and PFOA emissions by more than 99%, but also identifies persistent localized hotspots that overlap with dense populations, particularly in the Bohai Rim, Yangtze River Delta (YRD) and Pearl River Delta (PRD).
The study, conducted by researchers from Peking University, Shanghai Jiao Tong University and Southern University of Science and Technology, developed a bottom-up inventory at 0.1° × 0.1° resolution, tracking releases to air, water and soil from five PFOS and four PFOA source categories. The findings attribute the sharp declines to regulatory restrictions and technological transitions in fluoropolymer manufacturing, metal plating, aqueous film-forming foams (AFFFs) and sulfuramid pesticides. The work is detailed in a paper available at 10.1016/j.ese.2026.100785.
While the overall reduction is significant, the inventory reveals a structural shift in emission sources. In 2016, PFOS emissions were dominated by use-related releases, and PFOA emissions were overwhelmingly production-related. By 2021, AFFFs dominated residual PFOS emissions and nearly all residual PFOA emissions, concentrating releases at industrial and firefighting sites rather than dispersed agricultural and industrial uses. Water remained the principal receiving medium for both compounds.
The persistence of hotspots in the YRD and PRD, where residual sources coincide with dense populations, raises concerns about potential human exposure. PFOS and PFOA can accumulate in the human body and have been linked to immunotoxicity, endocrine disruption, developmental effects and certain cancers. A population-weighted emission index identified these two deltas as priority areas for monitoring and control. The authors recommend prioritizing monitoring of PFOS sources linked to metal plating and firefighting, and PFOA hotspots near fluoropolymer facilities.
The inventory offers spatially and temporally resolved source terms for multimedia fate modeling, exposure assessment and policy evaluation, providing a quantitative basis for hotspot mitigation. The authors also call for facility-level mass-balance measurements and China-specific process-level emission factors to improve future inventories, and for expanding compound coverage to replacement PFAS as nationally consistent activity data become available. Such work could help assess the health benefits of source-control strategies and inform future regulatory priorities.
The study’s findings are particularly relevant for environmental regulators and industries in China’s eastern and southeastern industrial zones, where legacy C8 PFAS emissions are now increasingly concentrated. As the country continues to phase out these chemicals under the Stockholm Convention, the research underscores the need for targeted control measures at remaining hotspots to protect public health. For more information about the journal and its scope, visit Environmental Science and Ecotechnology.
