The Effects of Heavy Metal Contamination on Antioxidant Enzyme Activity and Oxidative Stress in the Earthworm Perionyx excavates

This research work was carried out to ascertain the toxic effects of heavy metals mercuric chloride, copper sulphate and zinc sulphate their combination on anti-oxidative enzymes viz. Superoxide Dismutase, Catalase and Glutathione-S- transferase in Perionyx excavates. The worms for this work were collected and were exposed to different concentrations of heavy meals. The lower and higher concentration calculated were 25 and 30 mg/kg dry soil for mercuric chloride, 60 and 150 mg/kg of dry soil for copper sulphate and 140 and 350 mg/kg of dry soil for zinc sulphate respectively for 5 days. A dose and time dependent increase in activities of these enzymes was observed. Mercuric chloride was found to be more toxic at its highest concentration followed by the highest concentration of combination of both metals Copper sulphate and zinc sulphate.