An insight into the environmental and human health impacts of per- and polyfluoroalkyl substances (PFAS): exploring exposure pathways and their implications

Per- and polyfluoroalkyl substances (PFAS) have become a significant global environmental issue due to their widespread presence in the environment and their potential to have detrimental effects on human health. This study provides a comprehensive overview of PFAS, including the physicochemical properties of different PFAS compounds and their sources in various environments. Human biomonitoring (HBM) studies are also examined to assess the extent of exposure to and accumulation of these contaminants in human tissues and biological media. HBM of PFAS typically involves analyzing blood (serum and plasma), as well as human milk and urine. Studies have frequently detected PFAS in human serum, with varying concentrations. Serum PFOA and PFOS levels differ significantly across regions, with China reporting concentrations as high as 191 ng/mL for PFOA and 14 ng/mL for PFOS in some populations, while African countries report much lower levels, with medians of 0.12 ng/mL for PFOA and 0.53 ng/mL for PFOS. These regional disparities highlight variations in PFAS exposure and usage. Human milk is also a valuable matrix for assessing human exposure to PFAS, with studies showing that PFOA (Perfluorooctanoic Acid) and PFOS (Perfluorooctane Sulfonate) remain the two predominant PFAS in human milk. Furthermore, this review assesses the health effects of PFAS exposure on vulnerable populations, including fetuses, infants, children, and adolescents. Results identified that PFAS are environmental contributors to adverse fetal growth and birth outcomes. Exposure during pregnancy and early childhood is associated with various adverse outcomes, including Low birth weight (LBW), fetal growth restriction, and developmental problems. Some studies have also found links between exposure to PFAS and cognitive and behavioral development in children, including attention-deficit hyperactivity disorder (ADHD), lower IQ, and anxiety. While scientific evidence is not yet definitive, further research is required to determine the full extent of the health impacts of PFAS exposure during these sensitive developmental periods. Research has established a link between PFAS exposure and various health risks in children and adolescents, including ADHD, behavioral difficulties, precocious puberty, kidney disease, thyroid hormone disruption, and changes in reproductive hormone. Therefore, continuous actions should be conducted to mitigate PFAS contamination and minimize its impact on human health. This comprehensive review highlights the intricate nature of PFAS contamination and emphasizes the necessity for ongoing research to inform risk assessment, policy development, and public health interventions. The insights garnered from this review will be invaluable to researchers, policymakers, and regulatory agencies seeking to grasp the extent of PFAS contamination and its consequences for environmental sustainability and human health.