Assessment of the toxicity of organochlorine pesticide endosulfan in clams Ruditapes philippinarum

• It is the first research to study the toxicity of EDS on marine bivalve mollusks.
• We selected potential biomarkers for EDS pollution in the present study.
• Our results can devote to investigation of EDS stress mechanism in marine organisms.
• Our results may be used in future environmental monitoring of EDS.

This study is aimed at evaluating the effects of endosulfan in clams (Ruditapes philippinarum). For this purpose, a study was performed on clams exposed to 0.005, 0.05 and 0.5 μg/L endosulfan for 15 days. S ubsequently, the level of ethoxyresorufin-O-deethylase (EROD) activity, glutathione-S-transferase (GST) activity, glutathione (GSH) content, superoxide dismutase (SOD) activity, lipid peroxidation (LPO) and DNA strand break was determined in gills and digestive glands. Among the parameters, endosulfan caused significant changes in induction of EROD activity and oxidative stress in clams R. philippinarum. The exposure to endosulfan increased the concentration of EROD, GST, GSH, MDA and decreased the concentration of SOD. Moreover, according to the correlation analysis results, the EROD activity and GSH content in digestive gland as well as GST activity, LPO and DNA damage in both tissues had excellent correlation with endosulfan concentration. These results provided information on potential biomarkers that could be effectively applied to the biomonitoring of aquatic ecosystem in areas susceptible to persistent organochlorine compounds contamination, and also information on toxic effects.