To Örebro University

Per- and polyfluoroalkyl substances (PFASs) are synthetic chemicals widely used for their water- and stain-resistant properties but are increasingly concerning due to their persistence, toxicity, and mobility in the environment. With more time spent in vehicles, car interiors treated with PFAS may represent a significant human exposure pathway, particularly through dermal contact as PFAS migrate via hand sweat. This study investigated the presence of target PFAS in car interior materials and their potential mobility in human sweat. A total of 23 samples of textiles, leather, and foam were collected from six cars of four models (Volvo, Peugeot, Citroen, and Kia). PFAS were extracted in chemical extraction using sonication, cleaned by Envi-Carp Solid Phase Extraction (SPE), and analyzed using ultra-performance liquid chromatography coupled with tandem mass spectrometry UPLC-MS/MS. The chemical extraction indicated the presence of many PFAS compounds in the materials, compared with the limited migration ability in sweat extraction. Short-chain PFCA (≤ 7 carbon atoms) and PFSA (≤ 6 carbon atoms) were consistently detected compared to long-chain compounds. All ΣPFAS in the samples were below the restricted limit by REACH of 250 ng/g (Vestergren et. al., 2024). Dermal exposure was assessed by incubating five materials, a leather sample (ID EL20-003:237), three textile samples (ID EL20-003:370, EL20-003:373, and EL20-003:408), and a foam sample (ID EL20-003:373), in synthetic sweat at 37 °C for two hours, followed by SPE extraction and UPLC-MS/MS analysis. The seat belt textile (ID 373) was suggested as the highest dermal exposure risk, contributing 0.31 ng/g of sum PFAS. Reported compounds within the acceptable recovery range of 50-120% were PFBA, PFHxA, PFHpA, PFOA, PFNA, PFBS, PFPeS, PFHxS, PFHpS, PFOS, PFNS, & PFDS. Not recovered compounds were not reported and marked with NR (Not Reported), such as: PFPeA, PFDA, PFUnDA, PFDoDA, PFHxDA, 4:2 FTSA, 6:2 FTSA, 10:2 FTSA, and 12:2 FTSA. Overall, findings confirm that car interiors, particularly textiles, can act as PFAS sources, with significant potential for dermal exposure via sweat, underscoring the need for further assessment of human health risks.