Genotoxicity Screening of Leachates from Solid Industrial Wastes Evaluated with the Allium Test
Peter G. Odeigah, Jide Ijimakinwa, Bimbo Lawal and Rebecca Oyeniyi
Six solid wastes from the metal industry, from the chemical industry and from the production of pesticides were investigated for their toxic and genotoxic properties by using the Allium test. To simulate environmental conditions and better assess their environmental impact, the solid wastes were leached with water, and the water-extractable micropollutants were lyophilised before screening. The mean root lengths of onions exposed to different concentrations of the leachates were measured, and EC50 values were determined from the growth curves. The EC50 values of the wastes were ranked, in the order: organochlorine pesticide waste, settling tank sludge from a chemical company, paint sludge, lead slag, steel slag and aluminium slag. The leachates were also mitodepressive, and caused significant increases in the frequency of chromosome aberrations. These results demonstrate that the Allium test is a useful screening test for the evaluation and ranking of toxic industrial waste.