Distribution, partitioning behaviors, and source identification of legacy and emerging per- and polyfluorinated alkyl substances in the Pearl River Estuary, South China

Bin Tang; Can Peng; Dong-Jing Zhou; Kai-Yi Wu; Fei Tian; Hai-Gang Chen; Shi-Yi Zhang; Bo-Wen Li; Guo-Cheng Hu; Ming-Zhong Ren; Jing Zheng

doi:10.1016/j.watres.2025.124143

Distribution, partitioning behaviors, and source identification of legacy and emerging per- and polyfluorinated alkyl substances in the Pearl River Estuary, South China

Water Res. 2025 Jul 1:285:124143. doi: 10.1016/j.watres.2025.124143. Online ahead of print.

Authors

Bin Tang¹, Can Peng¹, Dong-Jing Zhou², Kai-Yi Wu², Fei Tian³, Hai-Gang Chen³, Shi-Yi Zhang², Bo-Wen Li⁴, Guo-Cheng Hu¹, Ming-Zhong Ren¹, Jing Zheng⁵

Affiliations

¹ Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China; College of Biology and Environmental Sciences, Jishou University, Jishou, 416000, Hunan, China.
² Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
³ Key Laboratory of Marine Ranching, Scientific Observing and Experimental Station of South China Sea Fishery Resources and Environment, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510300, China.
⁴ Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China. Electronic address: libowen@scies.org.
⁵ Key Laboratory of Environmental Pollution Health Risk Assessment, Research Center of Emerging Contaminants, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China. Electronic address: zhenging@scies.org.

PMID: 40614498
DOI: 10.1016/j.watres.2025.124143

Abstract

Estuaries serve as a sink for land-based pollutants like legacy per- and polyfluoroalkyl substances (PFASs), however, the environmental behaviors of emerging PFASs (ePFASs) remain largely unknown. This study investigated the occurrence, behaviors, and sources of 18 legacy PFASs and 13 ePFASs across the Pearl River Estuary (PRE). The results indicated that the total concentrations of PFASs (ΣPFASs) in seawater, suspended particulate matter (SPM), and sediment ranged from 1.20 to 25.6 ng/L, not detected (ND) to 635 ng/g dry weight (dw), and 0.93 to 6.84 ng/g dw, respectively. Perfluorooctanoate (PFOA) was the dominant chemical (25.4 %) in seawater, while sodium p-perfluorooctanoate nonenoxybenzene sulfonate (PFNOBS) for SPM (75.0 %) and sediment (37.9 %). PFASs exhibited a nearshore-to-offshore decreasing trend in seawater, while significant enrichment was observed in SPM and sediment at the river-sea junction, primarily attributed to urban/industrial discharges and the "marginal filtration effect". Partition coefficients (log K_d, log K_OC, and log K_p) exhibited strong linear correlations with carbon chain length of PFASs, indicated that long-chain PFASs were more readily adsorbed by the solid phase. SPM-mediated transport significantly enhanced long-chain PFAS distribution (log K_p =1.85-4.73), while salinity negatively influenced K_d of short-chain PFCAs (p < 0.05). Source apportionment analysis revealed the diverse sources of PFASs, including electronics, electroplating, textiles, papermaking, food packaging and emerging fluorochemical manufacturing, which aligns with PFAS releases from industrial processes and commercial products within the Pearl River Delta. Overall low ecological risk of PFASs was observed in the PRE, yet legacy PFOA and emerging substances, including 6:2 fluorotelomer sulfonic acid (6:2 FTSA), hexafluoropropylene oxide trimer acid (HFPO-TA), and PFNOBS, warrant attention due to their potential accumulation potential and associated risks. This study underscores the critical role of SPM in PFAS dynamics and provides significant insights into the partitioning behavior and sources of PFASs, particularly ePFASs, within estuarine aquatic systems.

Keywords: Ecological risk assessment; Hydrological properties; Legacy and emerging pfass; Source apportionment; Spatial variation.