Identification and health risks of per- and polyfluoroalkyl substances (PFASs) in soils from four circular economy industrial parks in China.

Per- and polyfluoroalkyl substances (PFASs) are widely used in electronics, surface protection, and other sectors due to their unique chemical properties. Electronic waste dismantling via incineration or pyrolysis is a significant source of environmental PFASs, yet knowledge of PFAS emission features in circular economy industrial parks (CEIPs) remains limited. This study addressed this gap by investigating PFAS contamination in four representative CEIPs of China. A total of 196 soil samples were collected, and 25 PFAS compounds were quantified. PFASs were detected in all samples, with concentrations ranging from 0.082 to 23.3 ng/g dry weight (dw) and median values of 0.844-2.63 ng/g dw. Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) exhibited the highest relative abundances. As a PFOS alternative, PFBS concentration disparities may indicate regional industrial development levels related to e-waste generation. Other emerging PFASs were generally present at low concentrations, suggesting that traditional PFASs remain prevalent in dismantled e-waste, although emerging alternatives warrant future attention with the ongoing dismantling of new e-wastes. Higher PFAS concentrations were observed in adjacent farmlands, particularly downstream of rivers through CEIPs, indicating river-borne PFAS enrichment in farmland soils. Human activities in these areas also accelerate the accumulation of PFAS in the soil environment. Current levels pose no obvious health risks, although cumulative pollution from increasing e-waste dismantling requires continuous monitoring. This study enhances understanding of PFAS contamination in Chinese CEIPs and, to the best of our knowledge, for the first time, reports PFAS enrichment in adjacent farmlands, highlighting the need for strengthened agricultural soil monitoring.