Chapter 3B: Biomarkers of Exposure: Perfluoroalkyl Compounds

Perfluorinated compounds (PFCs) are used in a multitude of industrial applications and consumer products. Owing to their physical–chemical properties they have become global environmental pollutants, and can be detected currently in practically all environmental media and biota, including humans. Although many PFCs show a variety of toxic effects in animal studies, epidemiological studies have so far not revealed any clear associations between human exposure to PFCs and health outcomes. Possible exposure pathways for the general population are outdoor and indoor air and particulates, diet, drinking water and direct contact with PFC-treated consumer products. Diet, particularly seafood, and the indoor environment seem to be the dominant exposure sources. External exposure assessment is complicated by the fact that intake of metabolizable precursors of PFCs will also contribute to the final body burden of persistent PFCs in humans. Human biomonitoring of PFCs results in an integrated measure of exposure to all kinds of PFCs from different sources and pathways. Human serum concentrations of PFCs have been recognized as the most suitable biomarker of exposure. In the general population, PFOS is the predominant PFC observed in human blood, with mean concentrations <40 ng/mL. Several studies have documented pre- and postnatal exposure. Following the phase-out and emission control of some PFCs, a clear decline in the serum concentrations from around the year 2000 has been reported in several studies.