Mutagenic and genotoxic effects of wastewater detected by the Allium test

Abstract

Screening for mutagens in complex environmental mixtures, such as industrial wastewater, is gradually being accepted as a routine method in environmental monitoring programs. The present study was carried out to evaluate the potential toxic and genotoxic effects of Marrakesh’s CMR wastewater, collected from Draa Lasfar mine located about 12km south-West of the city of Marrakech, Morocco. The results from the Allium test indicate that wastewater at 100 % concentration inhibits root growth and mitotic indices; induces binucleated cells as a function of the proportion, but is not toxic at very low concentrations. Marrakesh's wastewater CMR leads to a decontrol in the cellular division, bringing about polyploid cells. In this work, we show the evidences that the exceeding genetical material of theses polyploidizated cells tend to be eliminated from the nucleus in the form of micronucleus. Our analyses prove this fact, both by the presence of a number of cells carrying a micronucleus, and by the evidences of the elimination of the exceeding material itself.
The wastewater sample was analyzed by flame atomic absorption spectrometer for Zn, Pb, Cu and Cd, whose presence could partly be responsible for the toxicity of wastewater. The study concludes that the classical Allium test can give a more comprehensive data when done in combination with analysis by flame atomic absorption spectrometer. Also when wastewater is used for other purposes in combination with soils, it should be judiciously used at very low concentrations in order to protect the ecosystem health from any potential adverse effects.