Perfluorooctane sulfonate (PFOS) is an industrial chemical that has been used as a surfactant and surface protector for more than fifty years. It has during the last decade emerged as an environmental contaminant due to its widespread presence in humans and wildlife and its persistant, bioaccumulative and toxic properties. PFOS is developmentally toxic and late in utero exposure in rodents affects neonatal survival and growth. Observed symptoms suggest impaired pulmonary function, but the cause of the mortality has not been clarified. The purpose of this study was to determine the perinatal tissue distribution of S35-labelled PFOS in mice using whole-body autoradiography (WBA) combined with liquid scintillation counting (LSC). Pregnant C57Bl/6 mice were dosed orally on gestation day (GD) 16 and sampled on GD18, GD20 and postnatal day (PND) 1 (dams + pups). The results from the WBA and the LSC were unequivocal. In dams, PFOS accumulated primarily in the liver, but also the lungs contained levels higher than the blood. PFOS was readily transferred to the fetus. At GD18 general PFOS levels were higher in the fetus than in the blood of the corresponding dam with accumulation in the liver. At GD20, general PFOS levels remained higher in the fetus than in the dam, with substantial accumulation also in the lung. The accumulation in the lung persisted at PND1. Our results show that the fetus is exposed to higher levels of PFOS than the dam and point towards the lung being the main perinatal target organ of PFOS.
2009. S147- p.