Perfluorooctanoic Acid and Its Short-Chain Substitutes Induce Cytotoxic and Prooxidative Changes in Human Peripheral Blood Mononuclear Cells: A Comparative Study.

Perfluorooctanoic acid (PFOA) and its short-chain substitutes, perfluorohexanoic acid (PFHxA) and perfluorobutanoic acid (PFBA), are persistent environmental pollutants associated with widespread human exposure through occupational and environmental routes. The aim of this was to investigate the effects of PFOA, PFHxA, and PFBA on the intracellular level of adenosine-5'-triphosphate (ATP) in human peripheral blood mononuclear cells (PBMCs) and their viability, size, and granularity. Moreover, oxidative and nitrosative stress was assessed based on the levels of reactive oxygen species (ROS), reactive nitrogen species (RNS), and highly reactive oxygen species (hROS, mainly hydroxyl radical). Finally, oxidative damage to protein and lipids in PBMCs was measured. The cells were incubated for 1 h and 24 h at concentrations correlated to human occupational and environmental exposure (0.001-200 µg/mL) to the substances. Our findings indicate that PFOA and its short-chain analogs cause different effects in human PBMCs. PFOA induced statistically significant alterations almost in all studied parameters, substantially decreasing cell viability and ATP level and altering the size and granularity of tested cells; in contrast, PFHxA and PFBA induced significant changes only at some studied parameters. PFOA also induced a notable increase in intracellular ROS and RNS levels, which suggest that both oxidative stress and nitrosative stress influence its cytotoxic potential. Interestingly, the shortest-chain compound, PFBA, induced changes that were not observed for PFHxA. This suggests that the length of the chain determines the triggering of certain alterations in PBMCs. Importantly, the changes were noted at concentrations corresponding to those associated with occupational exposure. These findings contribute to our understanding of the immunotoxicity of PFOA and its substitutes, indicating the potential health risks associated with chronic exposure, particularly in populations with occupational exposure or high environmental PFOA burdens.