In vivo genotoxic effects of industrial waste leachates in mice following oral exposure.

Contamination of ground water by industrial waste poses potential health hazards for man and his environment. The improper disposal of toxic wastes could allow genotoxic chemicals to percolate into ground waters, and these contaminated ground waters may produce toxicity, including mutation and eventually cancer, in exposed individuals. In the present study, we evaluated the in vivo genotoxic potential of leachates made from three different kinds of industrial waste (tannery waste, metal-based waste, and waste containing dyes and pigments) that are disposed of in areas adjoining human habitation. Three different doses of test leachates were administered by oral gavage for 15 consecutive days to Swiss albino mice; their bone marrow cells were examined for chromosome aberrations (CAs), micronucleated polychromatic erythrocytes (MNPCEs), and DNA damage using the alkaline Comet assay. Exposure to the leachates resulted in significant (P < 0.05 or P < 0.001) dose-dependent increases in chromosome and DNA damage. Fragmented chromosomes and chromatid breaks were the major CAs observed. Chemical analysis of the leachates indicated that chromium and nickel were elevated above the limits established by health organizations. The highest levels of genotoxicity were produced by the metal-based leachate and the tannery-waste leachate, while the dye-waste leachate produced weaker genotoxic responses. The cytogenetic abnormalities and DNA damage produced by the leachates indicate that humans consuming water contaminated with these materials are at increased risk of developing adverse health consequences.