2010 Volume 56 Issue 1 Pages 104-111
Perfluorinated compounds are widespread in the environment, animals, and humans, and have been proposed to be included in the list of persistent organic pollutants that have the potential to cause a global pollution problem similar to that caused by existing persistent organic pollutants. Daphnia magna was used to evaluate the chronic effects of the ammonium salt of pentadecafluorooctanoic acid (PFOA) and the potassium salt of perfluorooctane sulfonate (PFOS) on the reproduction and biochemical responses of aquatic animals. Reproduction of Daphnia magna was a more sensitive response than survival or enzyme activities in daphnia exposed to PFOA or PFOS. No observed effect concentrations (NOECs) of daphnia reproduction were 1 and 10 mg/l after 21 days of exposure to PFOA and PFOS, respectively. The median lethal concentration (LC50) and survival NOEC values of PFOA for Daphnia magna were all greater than 100 mg/l after 21 days of exposure. The LC50 and survival NOEC values of PFOS were 9.1 mg/l and 5 mg/l after 21 days exposure. No significant changes in cholinesterase, catalase and heme peroxidase activities were observed between controls and exposure to PFOA or PFOS. This suggests that these enzyme activities are not sensitive biomarkers of exposure to these two chemicals or their effects in daphnids after chronic treatment. Based on the results of this study and other findings published in the literature, it is suggested that current PFOS and PFOA levels in freshwater may have no harmful impact on the aquatic environment. However, more information on the long-term ecological effects of PFOS and PFOA on diverse aquatic species is still needed to provide important information for adequately assessing the ecological risks of PFOS and PFOA.
