Temporal Trends in Exposure to C4-C8 Perfluoroalkyl Substances among U.S. Adults

摘要

Aim: Polyfluoroalkyl and perfluoroalkyl substances (PFASs) may persist in people and the environment. Since early 2000s, manufacturing practices of some PFASs, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA), have changed, and shorter alkyl-chain PFASs are increasingly used in commerce. Because short-chain PFASs have been detected in tap and surface water, interest exists in evaluating human exposure to these chemicals. Unlike PFOA and PFOS, short-chain PFASs have relatively short elimination half-lives and likely eliminate in urine. Methods: In 2001, 2009, 2012, and 2015, we collected 431 spot urine samples anonymously from convenience groups of demographically diverse adults in the Southeastern United States. We assessed exposure to C4-C8 PFASs from the urinary concentrations of PFASs quantified by mass spectrometry; limits of detection (LODs) were at or below 0.1 ng/mL for all PFASs. Results: We did not detect perfluorobutane sulfonate, perfluorohexane sulfonate, or PFOA. By contrast, we detected perfluorobutanoic acid (PFBuA), perfluoropentanoic acid (PFPeA), and perfluorohexanoic acid (PFHxA) in samples collected in 2015. PFBuA was most frequently detected (>50%) with 90th percentile concentration at 0.35 ng/mL; detection frequency and 90th percentile concentrations for the other compounds were 28%, 0.14 ng/mL (PFPeA) and 5%,