AUTHOR=Wang Miao-Miao , Xia Zhiqiang , Jiang Jianming , Wu Haigang , Huang Hurong , Zhang Xilong , Hong Wen-Jun , Li Minjie , Guo Liang-Hong TITLE=Per- and polyfluoroalkyl substances in coastal plain water network areas: shifting management focus to sediments JOURNAL=Frontiers in Marine Science VOLUME=Volume 12 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1586800 DOI=10.3389/fmars.2025.1586800 ISSN=2296-7745 ABSTRACT=IntroductionPer- and poly-fluoroalkyl substances (PFAS) are of great concern due to harm to human and wildlife health. Local-scale studies, especially those focused on ecologically important or densely populated areas, are critical to effective management, such as prioritizing resource allocation.MethodsTo prioritize management efforts, we investigated the distribution of PFAS in a densely populated coastal plain water network area in east China, followed by health and ecological risk assessments.ResultsResults demonstrated that ∑18PFAS (212.86-406.73 ng/L) in water had non-significant seasonal and weak spatial variations. Individual congeners, not the ∑PFAS concentrations, were significantly correlated with some water quality parameters. ∑PFAS in sediments, not surface water, demonstrated a significant negative relationship with river width. The perfluoroalkyl carboxylic acids (PFCAs) dominated the PFAS (water: 84.9%; sediments: 76.9%), while sediments harbored more perfluoroalkyl sulfonic acids than surface water (PFSAs; 23.1% vs. 15.1%). Spatial variation of ∑PFAS was much more profound in sediments than surface water (CV: 83.7% vs. 14.1-46.3%). Despite a low-moderate risk to water birds (RQ: 0.069-0.16), we found neither evident ecological risks to other aquatic organisms (RQ < 0.01) nor human health risks of the water PFAS.DiscussionOur findings revealed the divergent distribution pattern of PFAS in surface water versus sediments in coastal plain water network areas, likely due to presumable well-mixed conditions caused by tidal cycles and local water level regulations. Our work suggests that management focus of PFAS pollution should be shifted to sediments to optimize resource allocation in such coastal plain water network areas.