Long-Term Toxicity Effects of Cadmium and Lead on Bufo raddei Tadpoles

摘要

Cadmium (Cd) and lead (Pb), entering aquatic systems from industrial and consumer waste can cause contamination of the aquatic environment. As a result of bioaccu-mulation when they enter the food chain, Cd and Pb can cause serious damage to physiological processes or tissues in aquatic organisms even at concentrations far below the lethal level (He et al., 2005). Erythrocytic micronuclei (EMN) and erythrocytic nuclear abnormalities (ENA) have been routinely applied to assess water quality and the genotoxicity of contaminants on organisms (Chandra and Khuda-Bukhsh, 2004; Zhu et al., 2004). Superoxide dismutase (SOD) is an enzyme that can scavenge superoxide anions and protect organisms from adverse effects. Adenosine triphosphatase (ATPase) is an enzyme that catalyzes adenosinetriphosphate hydrolysis and provides chemical energy for organisms. The activities of SOD and ATPase have been used as biomar-kers for assessing water quality (Achuba, 2002; Brauner et al., 2003).