Perfluorinated alkyl substances in Spanish adults: Geographical distribution and determinants of exposure

Per- and polyfluoroalkyl substances (PFAS) are widely found in humans and the environment. Their persistence, bioaccumulation and toxicity make them a source of increasing public health concern. In this study, we analyzed the concentrations and geographical distribution of six PFAS in the serum of 755 Spanish adults aged 18-65. The geometric mean concentrations (and P95 values) for PFOS (perfluoroctane sulfonate), PFOA (perfluorooctanoic acid), PFHxS (perfluorohexane sulfonate), PFNA (perfluorononanoic acid) and PFDA (perfluorodecanoic acid) were 7.67 (19.3), 1.99 (5.48), 0.91 (2.84), 0.96 (2.44) and 0.42 (0.99) μg/L, respectively. N-Methylperfluorooctane sulfonamide (N-MeFOSAA) was detected in only 3.3% of samples. Residents in northeast (Catalonia) and northwest of Spain (Galicia) were found to have the highest serum values, whereas residents in the Canary Islands had the lowest values for almost all PFAS. Men presented higher levels than women, and we confirm that lactation (breastfeeding) contributes to a reduced body burden for all PFAS in women. Our data provide new information on exposure to PFAS in a national cross section sample of Spanish adults, thus providing a proxy for reference values for the Spanish population and forming the base for following temporal trends in the future.Thanks P. Pärt for the critical reading and constructive comments and to J.P Arrebola for his contribution to the data analysis and maps. This work was funded as part of a research agreement between the Spanish Ministry of Agriculture and Fisheries, Food and the environment and the Institute of Health Carlos III (Project N_ SEG 1251/07, 1210/10 and 1321/15). The authors would like to thank M. A. Lucena and the volunteers of BIOAMBIENT.ES and healthcare staff from the Societies for Prevention of IBERMUTUAMUR, MUTUALIA, MC-PREVENCIÓN, MUGATRA, UNIMAT PREVENCIÓN, and PREVIMAC