Sex-Specific Bioaccumulation, Maternal Transfer, and Tissue Distribution of Legacy and Emerging Per- and Polyfluoroalkyl Substances in Snakes () and the Impact of Pregnancy.

By Mei-Xia Ye, Xiao-Jun Luo, Yu Liu, Chu-Hong Zhu, Qun-Jie Feng, Yan-Hong Zeng, and Bi-Xian Mai
Environ Sci Technol
March 7, 2023
DOI: 10.1021/acs.est.2c09063

The effects of sex and pregnancy on the bioaccumulation and tissue distribution of legacy and emerging per- and polyfluoroalkyl substances (PFASs) in Chinese water snakes were investigated. The bioaccumulation factor of PFASs showed a positive correlation with their protein-water partition coefficients (log ), and steric hindrance effects were observed when the molecular volume was > 357 Å. PFAS levels in females were significantly lower than those in males. The chemical composition of pregnant females was significantly different from that of non-pregnant females and males. The maternal transfer efficiencies of perfluorooctane sulfonic acid were higher than those of other PFASs, and a positive correlation between the maternal transfer potential and log was observed for other PFASs. Tissues with high phospholipid content exhibited higher concentrations of ∑PFASs. Numerous physiological changes occurred in maternal organ systems during pregnancy, leading to the re-distribution of chemicals among different tissues. The change in tissue distribution of PFASs that are easily and not-so-easily maternally transferred was in the opposite direction. The extent of compound transfer from the liver to the egg determined tissue re-distribution during pregnancy.

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