Ecotoxicological effects of earthworm following long-term Dechlorane Plus exposure

Dechlorane Plus (DP), similar to persistent organic pollutants, has been widely detected in environmental matrices, especially in sediment and soil. In this study, earthworms Eisenia fetida were exposed to 0.1, 0.5, 6.25 and 12.5 mg kg(-1) DP for 28 d. Lethality, oxidative stress, neurotoxicity and cellulase of E. fetida were assessed to investigate ecotoxicological effects of DP after long-term exposure. Results showed that the direct toxicity of DP was very low. However, death rate, as well as SOD activity, together with changes in activities of CAT, GSH-Px, and GSH levels, indicating that oxidative stress may play a significant role in DP exposure. In addition, DP also changes the AChE and cellulase activity of earthworms even under low DP concentration after long-term exposure. Moreover, comet assay results showed that DP exposure increased the levels of tDNA significantly (p < 0.05) even in the lowest treatment (0.1 mg kg(-1) DP). Combined with the results of enzyme activity, oxidative damage and comet assay, it can be suggested that earthworms experience more stress of DP during long-time exposure. This study provides insight into the toxicological effects of DP on earthworm model, and may be useful for risk assessment of DP on soil ecosystems.