Antioxidant defense system responses and DNA damage of earthworms exposed to Perfluorooctane sulfonate (PFOS)

► We studied the potential ecotoxicity of PFOS to earthworm in soil. ► Eisenia foetida was used as a model organism and its growth was generally inhibited. ► Antioxidant enzyme activities were initially activated and then inhibited. ► Reduced glutathione content was observed and malondialdehyde content was elevated. ► PFOS induced DNA damage in earthworms.