Genotoxicity of leachates from a rural waste dump using two bioassays

Abstract

The potential mutagenic effect of raw and simulated leachate from “Odo-Oba” refuse dump site in South-West Nigeria was evaluated. Two genetic bioassays: The Allium cepa assay and the murine sperm-head morphology test were utilized. In the A. cepa assay, roots of Allium at about 2 – 3 cm long were treated with 1%, 2.5%,
5%, 10% and 25% concentrations of the raw and simulated leachate samples for 24 hours. Different types of chromosomal aberrations were induced in the root meristems and this was significant at P < 0.05 level. There was also reduction in the number of cells dividing at the tested concentrations. In the murine sperm-head morphology test, five different concentrations of 1%, 2.5%, 5%, 10% and 25% of the raw leachates were administered to groups of 5 male mice. The sperm of the mice from the cauda epididymis were examined 5 weeks after treatment. A significant dose- responsive mutagenic effect was observed, and this was concetration-dependent with the highest concetration inducing the largest number of sperm-head deformity. The physico-chemical analysis of the leachate samples show substances
with known mutagenic and carcinogenic effects. Results obtained may be useful in the assessment of the hazardous effects of the chemicals in the leachate from waste dump sites.