Organofluorine Mass Balance Analysis of Whole Blood Samples in Relation to Gender and Age

Abstract

Studies have highlighted the increasing fraction of unidentified organofluorine (UOF) compounds in human blood, whose health effects are not known. In this study, 130 whole blood samples from the Swedish general population were analyzed for extractable organofluorine (EOF) and selected per-and polyfluoroalkyl substances (PFAS). Organofluorine mass balance analysis revealed that 60% (0−99%) of the EOF in female samples could not be explained by the 63 monitored PFAS; in males, 41% (0−93%) of the EOF was of unidentified origin. Significant differences between both age groups and gender were seen, with the highest fraction of UOF in young females (70% UOF, aged 18−44), which is contrary to what has been reported in the literature for commonly monitored compounds (e.g., perfluorooctane sulfonic acid, PFOS). Increasing the number of monitored PFAS did not lead to a large decrease of the UOF fraction; the seven highest PFAS (C8−C11 PFCAs, C6−C8 PFSAs) accounted for 98% of sum 63 PFAS. The high fraction of UOF in human samples is of concern, as the chemical species of these organofluorine compounds remain unknown and thus their potential health risks cannot be assessed.

Widening the Lens on PFASs: Direct Human Exposure to Perfluoroalkyl Acid Precursors (pre-PFAAs)

“…Progress in this area will greatly improve understanding of the importance of human exposure to pre-PFAAs and will contribute to closing the mass balance on organofluorine in human blood. Total organic fluorine measurements indicate the likely presence of unknown PFASs in human blood from the general population, , but only a handful of novel PFASs have been identified in human serum. ,− The presence of unidentified pre-PFAAs, including intermediate transformation products, has been raised as a potential contributor to the unknown PFAS fraction in serum from the general population …”

Comprehensive Exposure Studies of Per- and Polyfluoroalkyl Substances in the General Population: Target, Nontarget Screening, and Toxicity Prediction

“…7,8 Target and extractable organic fluorine screening indicate that legacy PFASs contribute to a small proportion of total fluorine in humans, and a large number of novel PFASs are unknown. 9 At present, only a few toxicology studies have found that some perfluorinated alternatives may persist longer in humans, causing greater toxicity and potential health risks. 10,11 Therefore, novel PFASs may pose a potential hazard to human health.…”

“…Hydrosubstituted PFCAs (H-PFCAs). Six peaks (m/z 344.98−594.96) were identified as H-PFCAs (C = 7,8,9,10,11,12). The molecular formula error was between −2.83 and 0.65 ppm, and the RT increased with the number of carbon atoms.…”

A pilot study on extractable organofluorine and per- and polyfluoroalkyl substances (PFAS) in water from drinking water treatment plants around Taihu Lake, China: what is missed by target PFAS analysis?

“…Recent studies have identied EOF and different classes of emerging PFAS in various environmental media. [23][24][25][26][27][28][29] These techniques, however, were mostly applied to wastewater or biota samples. Studies focusing on drinking water are limited.…”