We evaluated whether life-time exposure to PFOS affects egg development, hatching, larval development, survival, metamorphosis and body mass of Enallagma cyathigerum (Insecta: Odonata). Eggs and larvae were exposed to five concentrations ranging from 0 to 10 000 mg/L. Our results show reduced egg hatching success, slower larval development, greater larval mortality, and decreased metamorphosis success with increasing PFOS concentration. PFOS had no effect on egg developmental time and hatching or on mass of adults. Eggs were the least sensitive stage (NOEC ¼ 10 000 mg/L). Larval NOEC values were 1000 times smaller (10 mg/L). Successful metamorphosis was the most sensitive response trait studied (NOEC <10 mg/L). The NOEC value suggests that E. cyathigerum is amongst the most sensitive freshwater organisms tested. NOEC for metamorphosis is less than 10-times greater than the ordinary reported environmental concentrations in freshwater, but is more than 200-times smaller than the greatest concentrations measured after accidental releases.
EWI Biomedical sciences