Retrospective monitoring of perfluorocarboxylates and perfluorosulfonates in human plasma archived by the German Environmental Specimen Bank.

Due to the increased awareness of the ubiquitous contamination of all environmental compartments and of human beings with perfluoroalkyl substances (PFAS), voluntary withdrawals and shifts in products and manufacturing technologies, as well as in regulatory measures, have been made. To investigate whether these activities are reflected in the human exposure to PFASS, we examined human blood archived by the German Environmental Specimen Bank. Plasma samples (n=258, age range 20-29 years) covering the observation period 1982-2010 were analyzed for eleven perfluoroalkylcarboxylates (C4-C14) and five perfluoroalkylsulfonates (C4-C10) by HPLC-MS-MS. We detected perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorohexanesulfonate (PFHxS) most often of all PFASs. Following a sharp increase from 1982 to 1986, median PFOS concentrations remained in the range of 20-24ng/mL until the end of the 1990s. Between 2001 and 2010, PFOS concentrations decreased steadily to 4ng/mL in plasma. Except for a similar strong increase from 1982 to 1986, we observed PFOA concentrations fluctuating between 4.8 and 6.3ng/mL in the following years. Since 2008, ESB data suggest a decreasing trend of PFOA. PFHxS concentrations increased continuously between 1982 and 2001 from about 1-2ng/mL. After nearly unchanged concentrations until 2005, a downward trend of PFHxS in plasma became apparent and in 2010 resulted in levels which were about 20% lower than those observed in the early 1980s. In the case of shorter and longer chained PFASs, quantification frequencies were between 0 and 60% and we found no indication of any temporal trends in human plasma concentrations.