HEAVY METAL POLLUTION IN KABWE AND PHYTOREMEDIATION OF LEAD CONTAMINATED SOILS

Up until 1994, Kabwe, Zambia was home to a very productive lead, zinc and cadmium mine. The mine was operated during times when there were little to no environmental regulations and, therefore, left widespread heavy metal (lead) contamination in the town. Recognition of this problem began in the 1970’s as indicated by research conducted on lead contamination in soils, plant and people. Another study conducted in 2006 highlighted the desperate need for immediate remediation action in Kabwe. A recent study funded by the World Bank investigated a variety of remediation methods to reduce lead exposure to children, but did not include phytoremediation. In this present study we investigated the role of plants in lead exposure and removal. Lead concentrations were quantified using Atomic Absorption spectrometry. The plants studied, Brassica rapa and Tithonia asteraceae, grow locally in the lead contaminated soils. Lead concentrations in the soils ranged from 27 to 328 ppm while plant concentrations were between 3 and 8 ppm. The study also investigates the potential of using Indian mustard (Brassica juncea), lawn grass, watermelon and Sunflower, in Phytoremediation of lead contamination. The plants are being exposed to varying lead concentrations and the amount absorbed by the plants is quantified.