BackgroundPer- and polyfluoroalkyl substances (PFASs) are highly fluorinated organic compounds that have been widely used in industry during the past few decades. The main exposure routes for PFASs are thought to be the diet, drinking water, and dust. In this study, we aimed to evaluate the relationship between perfluoroalkyl carboxylic acids (PFCAs, members of the PFAS family) and the plasma eicosapentaenoic acid-to-arachidonic acid ratio (EPA/AA), a biological indicator of seafood intake, to determine whether seafood intake may represent a means of exposure to PFASs in the Japanese population.MethodsWe performed a cross-sectional study using 131 plasma samples collected from residents of Kyoto, Japan in 2013 and held in the Kyoto University biological sample bank. The concentrations of perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluoroundecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA), EPA, and AA were quantified by gas chromatography-mass spectrometry, and multiple linear regression was used to analyze the results.ResultsIn multiple linear regression analyses with age and eGFR, PFOA showed a significant positive linear association with age (p= 0.0005); PFHpA showed a significant negative linear association with estimated glomerular filtration rate (eGFR;p= 0.0338); and PFHpA, PFOA, PFNA, PFUnDA, and PFDoDA exhibited significant positive linear associations with EPA/AA (p= 0.0358, 0.0056, 0.0242, <0.0001, and <0.0001, respectively). Because only PFHpA and PFOA were associated with smoking, their concentrations were examined again with smoking variable included and neither showed an association with smoking habit. PFOA showed a significant linear association with EPA/AA ratio (p= 0.0072), but PFHpA did not (p= 0.051).ConclusionsThe plasma concentrations of PFOA, PFNA, PFUnDA and PFDoDA significantly associated with the EPA/AA ratio in residents of Kyoto.