The Effects of Domestic Sewage on the Micronucleus and Abnormal Nucleus of Red Cell of Tadpoles

In this study,the mutagenic activity of influent, primary effluent and secondary effluent in Wuhan Sewage Treatment Plant (STP) were monitored by a micronucleus test using the erythrocytes of the tadpoles of the frog (Rana nigromaculata Hallowel1). In an experiment in which the tadpoles were exposed to domestic sewage for 16 days,the tadpole red blood corpuscles nuclear cell rates and core unusual cell rates showed a significant elevation after 2 days of exposure,and then increased over time to a maximum after 8 days.In another experiment in which the tadpoles were exposed to mixed sewage of different concentrations, the tadpole red blood corpuscles nuclear cell rates and core unusual cell rates showed significant dose-dependent increases. The results indicated that both domestic and mixed-sewage had strong mutagenic activity. And the primary effluent and secondary effluent have mutagenic activity too. The existing technology of treatment in STP should be improved.