Ecotoxicological evaluation of perfluorooctanesulfonate (PFOS)

Based on available toxicity data, protective screening-level concentrations of PFOS were calculated for aquatic and terrestrial organisms. Using the Great Lakes Initiative, water concentrations of PFOS were calculated to protect aquatic plants and animals. The screening plant value (SPV) protective of aquatic algae and macrophytes was calculated as 2.3mg PFOS/L. The secondary chronic value protective of aquatic organisms was 1.2μg PFOS/L. The screening-value water concentrations less than or equal to 1.2μg PFOS/L would not pose a potential risk to aquatic organisms. Because the aquatic benchmark is based on the most sensitive species, this benchmark should also be protective of other aquatic organisms, including amphibians. The tissue-based TRV for fish was determined to be 87μg PFOS/kgww. For terrestrial plants, a screening benchmark was determined to be 1.3 mg PFOS/kg soil ww or 1.5 mg PFOS/kg soil dw, whereas for soil invertebrates such as earthworms the benchmark value was 39mg PFOS/kgdw soil or 33mg PFOS/kgww soil. For avian species, dietary, ADI, and egg yolk-based benchmarks were determined as 0.28 mg PFOS/kg diet, 0.021mg PFOS/kg bw/d, and 1.7μg PFOS/mL yolk, respectively. Benchmarks for serum and liver for the protection of avian species were 1.0μg PFOS/mL and 0.6μg PFOS/gww, respectively. However, no-effect levels in laboratory studies suggest actual population-level effects would not be expected to occur until a concentration of 6.0 mg PFOS/kg in the diet, 5.0μg PFOS/gww in the liver, or 9.0μg PFOS/mL in the serum was exceeded, thus indicating the conservative nature of the benchmarks. © Springer 2006.