Contamination of Fish with Perfluorinated Chemicals Caused by Municipal Sewage Discharges

Wednesday, September 23, 2009: 10:50 a.m.
Andrea M. Schuetze , Institute of Food Technology and Food Chemistry, Technical University of Berlin, 13355 Berlin, Germany
Thomas Heberer, Ph.D. , Food Institute Oldenburg, Lower Saxony Federal State Office of Consumer Protection and Food Safety (LAVES), Oldenburg, Germany
Stefan Effkemann, Ph.D. , Institute for Fish and Fishery Products, Lower Saxony Federal State Office of Consumer Protection and Food Safety (LAVES), 27472 Cuxhaven, Germany
Perfluorinated chemicals (PFCs), especially the two major representatives perfluorooctanesulfonate (PFOS) and perfluorooctanoicacid (PFOA), are ubiquitously distributed in the aquatic environment. Recent investigations by Fei et al. (2009) suggest that PFOA and PFOS may reduce fecundity at levels commonly found in developed countries. 
To obtain an overview the state of contamination of edible fish and to trace the contamination sources different fish were caught from surface waters downstream from the sewers of municipal sewage treatment plants in Berlin but also from other more or less urbanized regions in Germany such as the Weser and the Elbe rivers, lake Storkow, the North Sea and the Baltic Sea. The examined fish included 51 wildlife eels, 44 breams, 5 herrings, 5 mackerels, 3 carps and 4 trouts. In these samples, PFOS was detected with concentrations up to 225.7 µg kg-1 fresh weight. The results indicate that residues of PFOS were much more dominant in fish than PFOA. PFOS was detected in the filet samples from highly populated and industrialized regions at levels between 8.22 and 225.7 µg kg-1 much higher than those in samples from remote marine locations (n.d. – 50.81 µg kg-1). 
To date, no final tolerable daily intake (TDI) for PFOS and PFOA has or could be fixed by any official national or international organization. For a provisional risk assessment results from a subchronic study in cynomolgus monkeys were used to derive a provisional TDI of 0.15 mg kg-1 b.w. per day (European Food Safty Authority (EFSA), 2008). This value would for an adult consumer already be reached for fish containing 30 µg kg-1 of PFOS presuming a consumption of 300 g fish per day. Based on this assumption, the detected residues of PFOS found in 33 out of 112 examined fish samples might be classified as potential risks for the health of consumers.