Unregulated Active and Closed Textile Mills Represent a Significant Vector of PFAS Contamination into Coastal Rivers

Despite concerns over the ubiquity of per- and polyfluoroalkyl substances (PFAS), little is known about the diversity of their sources to surface waters and their seasonal dynamics. Frequent use of PFAS in textiles means that both active and closed textile mills require evaluation as PFAS sources. We deployed passive samplers at seven sites in an urban river and estuary adjacent to textile mills in Southern Rhode Island (USA) over 12 months. We estimated monthly mass flows (g month–1) of perfluorohexanoic acid (45 ± 56) and perfluorooctanoic acid (30 ± 45) from the upstream river influenced by an active mill. Average mass flows were 73–155% higher downstream, where historical textile waste lagoons contributed long-chain perfluoroalkyl acids. Mass flows of perfluorononanoic acid increased from 7.5 to 21 g month–1 between the upstream and downstream portions of the rivers. Distinct grouping of the two main PFAS sources, active textile mills and historical waste lagoons, was identified using principal component analysis. Neither suspect screening nor extractable organofluorine analysis revealed that measurable PFASs were missing beyond the targeted compounds. This research demonstrates that both closed and active textile mills are important ongoing PFAS sources to freshwater and marine regions and should be further evaluated as a source category.