Fate and compositional profiles of perfluoroalkyl substances (PFASs) in multimedia environments

Abstract

Introduction: Perfluoroalkyl substances (PFASs), such as perfluoroalkyl sulfonates (PFSAs) and perfluorocarboxylic acids (PFCAs), are synthetic chemicals with oil and water repellency and thermal resistance properties. The compositional profile and the distribution of PFASs differ greatly among environmental matrices compared other POPs. The PFAS concentration in air is related to population density. High PFAS concentration in urban area is due to the traffic and the influence of product manufacturing plants. Wastewater treatment plants (WWTPs) are known to release PFASs directly to the aquatic environment due to the potential decomposition of precursors during wastewater treatment and the incomplete removal of PFASs from influent wastewater. The PFASs with long perfluoroalkyl chain are strongly bonded to sediments with high organic carbon content. The PFASs absorbed by biota are not easily degraded or excreted, resulting in bioaccumulation and bioamplification in the food chain. This study investigated PFASs in multimedia environments to confirm the effects of emission and release sources of PFASs and to elucidate their spatial distribution in a Korean river. Materials and Methods: The major sampling site is Hyung-san River located in Gyeongbuk, Korea. Sample types include air, surface water, influent and effluent of wastewater treatment plants, soil, sediment, sludge, plants, and fish. All samples were transported to the laboratory in ice packs at 4 °C and stored at -20 °C until analyses. All samples, spiked with 5 ng of the internal standard, were extracted using the SPE method. The recovery standard mixture was added to the samples and analyzed with an API 2000 triple quadrupole mass spectrometer (Applied Biosystems/MDS Sciex, Foster City, CA). Results and Discussion: The highest PFAS levels in air and surface water are detected near an industrial complex of Hyung-san River. In soil and sediment, high PFAS levels are detected in urban areas and near WWTPs. Perfluorobutane sulfonate (PFBS) is primarily detected in water, influent and effluent, whereas long chain perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS) are dominant in dust, soil, sediment, and sludge. Additionally, while PFBS and neutral PFASs are found in air, PFCAs are detected in plant and fish. The results indicate that PFCAs may be influenced by plant respiration, translocation, and bioaccumulation. The specific distribution patterns of PFASs in each environmental matrix illustrate the influences of surrounding environments, contaminant sources, and different physicochemical characteristics of each congener. This is the first study in which 6 neutral and 13 ionic PFASs were investigated simultaneously from nine different matrices. We suggest that this study would serve as a good model study for future environmental assessments and distribution of PFASs.