Transplacental exposure of neonates to perfluorooctanesulfonate and perfluorooctanoate: a pilot study.

OBJECTIVES: Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) can be released of perfluorinated compounds by biotic and/or metabolic decomposition. Due to their ubiquitous occurrence, persistence and bioaccumulative properties they can be found in blood of the general population all over the world. In animal studies PFOS and PFOA provoked cancer and showed developmental toxic potential besides other adverse health effects. On the basis of the comparison of maternal and umbilical cord plasma sample pairs we wanted to examine whether infants are exposed to PFOS and PFOA via their mothers' blood. METHODS: We determined PFOS and PFOA in 11 plasma samples of mothers and the 11 corresponding cord plasma samples of neonates. An analytical method based on plasma protein precipitation followed by HPLC with MS/MS-detection was employed. As internal standards we used 1,2,3,4-(13)C(4)-PFOS and 1,2-(13)C(2)-PFOA. RESULTS: We found PFOS and PFOA in every plasma sample analysed. In maternal plasma samples PFOS concentrations were consistently higher compared to those of the related cord plasma samples (median: 13.0 microg/l vs. 7.3 microg/l). In the case of PFOA we observed only minor differences between PFOA concentrations within the analysed sample pairs (median: 2.6 microg/l vs. 3.4 microg/l for maternal and cord plasma samples, respectively). DISCUSSION: For both substances a crossing of the placental barrier could be shown. For PFOS we observed a decrease from maternal to cord plasma concentrations by a factor of 0.41-0.80. To the contrary, PFOA crosses the placental barrier obviously unhindered. These findings show that neonates are exposed to PFOS and PFOA via their mothers' blood. Given the current situation that only little is known about the consequences of PFOS and PFOA exposure in the early state of development of humans and the fact that in animal studies both substances showed developmental toxic effects further research regarding human health effects is indispensable.

Occurrence of perfluorinated substances in an adult German population in southern Bavaria.

OBJECTIVES: Perfluorinated compounds (PFCs) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Because of their global occurrence in different environmental media, their persistence, and their potential to bioaccumulate in organisms they are of toxicological and public concern. METHODS: In the present study, the internal exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in 356 human plasma samples collected from an adult population in Germany in 2005 is quantified. RESULTS: We were able to detect the target analytes in all plasma samples and observed a significant correlation between the PFOS and PFOA concentrations. In female participants, the levels of PFOS and PFOA ranged between 2.5-30.7 (median: 10.9 microg/l) and 1.5-16.2 microg/l (median: 4.8 microg/l), respectively. In males we observed concentrations from 2.1 to 55.0 microg/l (median: 13.7 microg/l) for PFOS and from 0.5 to 19.1 microg/l (median: 5.7 microg/l) for PFOA. A significant correlation between both PFOS and PFOA concentrations and gender was observed. We also found increased levels of the PFCs with increasing age of the participants, but this association reached statistical significance among females only. CONCLUSIONS: Our data agree well with results of other recent studies in Europe and suggest that the current exposure of the adult German population is lower than the exposure of the US and Canadian population. The sources of human exposure are currently not well understood. Toxicological implications are restricted to animal studies and occupational investigations not adequate for quantitative risk assessment in humans. Overall, more scientific research is necessary to characterize the body burden of PFCs (especially for relevant subsets of the population) and the main sources and routes, which are responsible for human exposure and possible health implications of these compounds.