Effects of perfluorooctanoic acid and perfluorooctane sulfonate on acute toxicity, superoxide dismutase, and cellulase activity in the earthworm Eisenia fetida.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are the two best-known perfluorinated chemicals and have received much attention due to their ubiquity in the environment. In the present study, we evaluated the effects of PFOS and PFOA on acute toxicity, superoxide dismutase (SOD), and cellulase activities in Eisenia fetida. The results of acute toxicity testing using a filter paper contact test and a natural field soil test showed that PFOA and PFOS exhibited acute toxicity in earthworms, and the toxic effect of PFOS was greater than that of PFOA. The results also showed that avoidance behavior is a more sensitive and easy operation biomarker than acute toxicity and will give us information for early diagnosis of soil pollution, well before the lethal effect becomes apparent. Subchronic exposure to PFOA or PFOS resulted in changes in SOD and cellulase activities in E. fetida, and SOD activity was more sensitive than cellulase activity during early exposure. Based on these findings, we suggest that avoidance behavior and SOD activity in earthworms are suitable biomarkers for evaluating the toxicity of PFOA- and PFOS-contaminated soils. These results indicate that exposure to PFOA and PFOS has a potential impact on soil animals and their environment.