Journal des biomarqueurs Libre accès

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Oxidative Stress Associated with Pollutants from Coal Mining Activities on Aquatic Plants: A Case Study of Hwange, Matabeleland North, Zimbabwe

Joanna B. Change, Andrew H. Siwela, Norah Basopo

Pollution of water systems is a potential threat to human health as pollutants absorbed by primary sources in the food chain bio-accumulate. The aim of this study was to determine the impact of coal effluent on the oxidative stress status of aquatic plants. Water and plant samples were collected from four different sites in a coal mining area during the wet and dry seasons. Physical parameters of the water samples were measured on site. Effluent from an underground acid rock drainage point exhibited low pH and high levels of TDS and conductivity. Plants were analyzed for copper, zinc, cadmium and lead. High concentrations of lead and zinc were observed in plants sampled from all sites. Significantly higher metal concentrations were observed during the wet season than the dry season. Plant homogenates were used to determine the activities of superoxide dismutase, catalase, glutathione peroxidase and ascorbate peroxidase. Significantly higher enzyme activities were noted in plants sampled during the wet season compared to plants collected during the dry season. Continual alterations of antioxidant enzymes suggest the potential use of the plants for measuring the effects of coal mining activities. We also observed that the antioxidant systems of aquatic plants are well equipped to deal with oxidative stress induced by coal mining activities.