What is the effect of phasing out long-chain per- and polyfluoroalkyl substances on the concentrations of perfluoroalkyl acids and their precursors in the environment? A systematic review

Abstract

Background: There is a concern that continued emissions of man-made per-and polyfluoroalkyl substances (PFASs) may cause environmental and human health effects. Now widespread in human populations and in the environment, several PFASs are also present in remote regions of the world, but the environmental transport and fate of PFASs are not well understood. Phasing out the manufacture of some types of PFASs started in 2000 and further regulatory and voluntary actions have followed. The objective of this review is to understand the effects of these actions on global scale PFAS concentrations.Methods: Searches for primary research studies reporting on temporal variations of PFAS concentrations were performed in bibliographic databases, on the internet, through stakeholder contacts and in review bibliographies. No time, document type, language or geographical constraints were applied in the searches. Relevant subjects included human and environmental samples. Two authors screened all retrieved articles. Dual screening of 10% of the articles was performed at title/abstract and full-text levels by all authors. Kappa tests were used to test consistency. Relevant articles were critically appraised by four reviewers, with double checking of 20% of the articles by a second reviewer. Meta-analysis of included temporal trends was considered but judged to not be appropriate. The trends were therefore discussed in a narrative synthesis.

Prenatal exposure to perfluoroalkyl substances modulates neonatal serum phospholipids, increasing risk of type 1 diabetes

“…The two most abundant PFAS were PFOS and PFOA, detected in all subjects. Our detected levels of PFOS and PFOA were lower than reported in previous studies 19 , most of which used samples collected before 2010, and therefore before recent, noted decreases in population blood levels of PFOS and PFOA 31 .…”

Temporal trends of suspect- and target-per/polyfluoroalkyl substances (PFAS), extractable organic fluorine (EOF) and total fluorine (TF) in pooled serum from first-time mothers in Uppsala, Sweden, 1996–2017

“…Notably, Land et al reviewed PFAS temporal trend data published up until 2015 and concluded that there was no evidence for signicant declining trends in PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA and PFTeDA in human sample at any global location. 34 In the trend study on human milk from Stockholm, PFDA and PFTriDA did not display a change-point; instead these substances increased throughout the study period, while PFUnDA showed a CP in 1984, albeit with non-signicant trends before and aer this time. As mentioned before, differences in study design and sampling frequency may contribute to discrepancies between studies.…”

Simultaneous determination of perfluoroalkyl substances and bile acids in human serum using ultra-high-performance liquid chromatography–tandem mass spectrometry

“…PFASs, on the other hand, are a group of man-made chemicals that have been widely used since the 1950s in both household and industrial products. PFASs also have long biological half-lives, and are readily detected in humans [3][4][5][6][7]. Structurally, several PFAS compounds resemble endogenous fatty acids, with fluorine substitution in place of hydrogen.…”