Human exposure to PFAS and organofluorine compounds in northern Norway between 1986 and 2015: a fluorine mass-balance study in pooled human serum samples

• Main Authors: Cioni, Lara, Plassmann, Merle, Benskin, Jonathan, Coêlho, Ana Carolina, Nøst, Therese, Rylander, Charlotta, Nikiforov, Vladimir, Sandanger, Torkjel, Herzke, Dorte
• Format: Conference Object
• Language: unknown
• Published: 2022
• Subjects: Norway; Tromsø; Orleans; Northern Norway
• Online Access: https://zenodo.org/record/7234375; https://doi.org/10.5281/zenodo.7234375

Presentation at Dioxin 42nd International Symposium on Halogenated Persistent Organic Pollutants, New Orleans (October 2022) Abstract: Per- and polyfluoroalkyl substances (PFAS) are a class of over 4700 synthetic chemicals used in numerous industrial and consumer product applications1. The widespread use of PFAS has led to human and wildlife exposure globally. Despite their discovery in the environment nearly 2 decades ago, current analytical methods only monitor ~1 % of known PFAS, raising concerns that human PFAS exposure may be underestimated2. In this study, serum samples from the Tromsø study were pooled and analyzed for total fluorine (TF), extractable organic fluorine (EOF), total oxidizable precursors (TOP) and selected legacy PFAS. The aim was to evaluate concentrations of organofluorine compounds in blood collected between 1986 and 2015 in northern Norway estimating TF, EOF, portion of unidentified EOF and contribution of oxidizable precursors. Serum from the Tromsø study was collected in 1986, 2007 and 2015 from men and women living in Tromsø, Norway. For the present work, these samples were pooled based on sampling year, sex, age and type 2-diabetes diagnosis. The pooled samples (46 pools, 8-15 individuals in each pool) were analyzed for TF, EOF, TOP and selected legacy PFAS. TF and EOF measurements were performed using combustion ion chromatography directly on 100 μl of pooled serum and on 450 μl acetonitrile extracts (225 μl of serum), respectively, using previously validated methods3. For the TOP assay, 150 μl of serum was extracted with acetonitrile and oxidized using an optimized protocol for human serum4. Compound-specific PFAS analyses were performed on 50 μl of the EOF extracts and on the TOP assay extracts before and after oxidation. Differences between the sampling years as well as the influence of sex and mean age on the different fluorine fractions were assessed using multiple linear regression. TF (<25-1330 ng F/ml, mean: 126 ng F/ml in 1986, 79 ng F/ml in 2007, 73 ng F/ml in 2015) ...