Improper disposal of Municipal solid wastes (MSWs) is one of the major sources of environmental pollution in India. Leachates from these wastes contaminate our water sources. This study was carried out to determine the toxic effects of leachates from MSW in transgenic Drosophila melanogaster (hsp70-lacZ). Organisms were examined for Hsp70 expression, oxidative stress enzymes, proteotoxicity, tissue damage and effect on emergence and reproduction. Chemical analysis alone does not give insight into the biological effects of complex chemical mixtures (leachates).Bioassays are an important tool...