Occurrence of bisphenols, parabens and per- and polyfluoroalkyl substances in surface water of a highly urbanized river system: Temporal-spatial distribution and risk prioritization.

Abstract

Bisphenols (BPs), parabens (PBs), and per- and polyfluoroalkyl substances (PFASs) are emerging endocrine-disrupting compounds (EDCs) with potential ecological and health risks. Their co-occurrence, spatiotemporal distribution, and ecological risks in highly urbanized rivers remain largely unclear. In this study, 24 target EDCs, including 7 BPs, 5 PBs, and 12 PFASs, were investigated in the Shenzhen River, a typical highly urbanized cross-border river in southern China. The median concentrations of Σ7BPs, Σ5PBs, and Σ12PFASs were 33.50, 1.10, and 43.68 ng/L in the dry season, increasing to 38.25, 4.85, and 83.45 ng/L in the wet season. Σ5PBs showed significant seasonal increases, likely due to increased use of personal care products, while BPs and PFASs exhibited distinct compositional variations without significant changes in total concentrations, suggesting seasonal redistribution of individual compounds. Higher EDC concentrations occurred in midstream and downstream areas, potentially associated with sewage treatment plant discharges, industrial activities, and cross-border logistics, while upstream sites showed lower background levels. Positive Matrix Factorization (PMF) analysis indicated that traditional plastic manufacturing, personal care product use, and emerging industrial emissions were likely the main contributing sources. Ecological risk assessment based on the risk quotient (RQ) revealed that only PFOS posed high ecological risks, while other target compounds showed negligible risks. PFOS, BPA, BPS, BPAP, PFBS, and PFDS were identified as the priority compounds requiring regulatory attention via the ToxPi framework. These results provided a scientific basis for the targeted control of high-risk EDCs and water quality management in highly urbanized river systems.