Comprehensive Investigation on the Occurrence of Ultrashort-Chain PFASs in Foods and Their Dietary Exposure by a Total Diet Study in China

Research on ultrashort-chain per- and polyfluoroalkyl substances (PFASs) in foods is quite scarce. This study comprehensively investigates the occurrence and dietary exposure of ultrashort-chain PFASs through a China Total Diet Study. Trifluoroacetic acid (TFA), perfluoropropanoic acid (PFPrA), and trifluoromethanesulfonic acid (TFMS) were detected in foods, exhibiting distinct differences in their dietary and regional distributions, particularly in plant-origin foods. Among them, TFA was the most prevalent and contributed the most in all food samples, with concentrations ranging from 1.45 to 39.0 ng/g (wet weight). These levels were 2-fold to 3-orders of magnitude higher than those of PFPrA and TFMS and other chain-length PFASs previously found in the same samples. Data on dietary exposure assessment indicated that the estimated dietary intake (EDI) of TFA ranged from 172.7 to 660.3 ng/kg body weight/day, accounting for an average of 96.9% of the total exposure to ∑17 PFASs for the general population. Furthermore, a preliminary assessment suggests that diet played a more significant role than drinking water in human exposure to ultrashort-chain PFASs, with plant-origin foods contributing over 90% of the total dietary exposure. These findings underscore the necessity for monitoring ultrashort-chain PFASs to assess their potential health risks from dietary exposure.