Human Risks of Perfluorinated Chemicals (PFCs): a Review of the Literature

Abstract

Perfluorinated compounds (PFCs) are a family of chemicals used widely as surfactants, anti-staining products, impregnation agents and fire fighting foams. The wide possible uses for these compounds are due to their unique water- and oil repellent properties. Notable PFCs, like perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and others have been found in the (mainly aquatic) environment as well as animals and humans. Several studies have investigated the effects of these chemicals, mainly PFOS and PFOA, since the first observation in human serum. The literature available on PFC exposure and potential harmful effects in humans will be discussed. PFC exposure occurs through different routes. Indoor and outdoor air has been found to be contaminated with some degree of PFCs, from which inhalation is a form of exposure. Inhalation of contaminated house dust has been mentioned as a source of exposure as well. Most abundant route of exposure was found to be dietary, mainly through directly contaminated fish or food contaminated by PFCs through migration from the packaging. Ingestion of house dust by toddlers contributes to total exposure as well. Furthermore, occupational exposure may occur in PFC factories as well as occupations using PFC products, like ski-wax. Occupational levels of PFC exposure have been found to be several orders of magnitude higher than general population levels. Many effects have been found to be associated with PFC exposure, mainly PFOS and PFOA, for the most part investigated in rodents. Only few effects have been observed at exposure levels comparable to the general population. Immunotoxic effects were found in relevant concentrations in rodents, causing a reduction in immune response. Epidemiological effects in the general population include reprotoxic effects, like reduced sperm count, and a recent study observed a positive correlation between PFC levels in serum and Attention Deficit Hyperactive Disorder (ADHD) in children. Higher perceived adverse effects, like carcinogenicity and neurotoxicity, have been observed in rodents, but in higher concentrations and these have not been found in the general population or the occupationally exposed. In conclusion, epidemiological data provides the most convincing evidence of adverse effects due to PFC exposure. More toxic effects found in rodents increase the potential risk of these compounds in humans as well. Further investigation of PFOS and PFOA, but also other PFCs less abundant in humans, is needed to completely assess the risks of PFCs for humans. It is evident that the unrest caused by these compounds is substantiated, and deserves more attention.