A review of the occurrence and distribution of Per- and polyfluoroalkyl substances (PFAS) in human organs and fetal tissues

This review synthesizes current evidence on PFAS concentrations across human organs and tissues, excluding blood matrices. Literature search was conducted using PubMed, Web of Science, and Scopus. The earliest reported study on the topic measured PFOS, PFOSA, PFOA, and PFHxS levels in human liver and serum, showing mean liver concentrations of 18.8 ng/g and a liver-to-serum ratio of 1.3:1 for PFOS. Subsequent research extended these findings to other organs, with measurements in pooled samples indicating organ-specific accumulation patterns. PFOS was predominant in liver, kidney, and lung, while PFOA was more prominent in bone. Pathological conditions, such as liver disease, have shown to influence PFAS distribution, with diseased tissues exhibiting altered accumulation patterns. On the other hand, the occurrence of PFAS in fetal and placental tissues demonstrated that these compounds cross the placenta, although fetal exposure levels were significantly lower than maternal levels. Tissue-specific accumulation has been reported, with liver and lung showing higher concentrations compared to other fetal tissues. Associations between PFAS levels in the placenta and birth outcomes indicated potential sex-specific effects, including reduced birth weight in male infants exposed to higher PFOS levels. This review highlights important differences in the detection frequencies and concentrations of PFAS across organs and the specific studies. These variations are attributed to differences in analytical methods, sample characteristics, and exposure sources. The findings underscore the need for standardized methodologies and further research to better understand PFAS distribution in human tissues and their potential health impacts, particularly during critical developmental stages.