Cadmium and Lead uptake

Heavy metal contamination of agricultural soils from wastewater irrigation, application of sewage and air deposition from the atmosphere is a major concern to food production. Systemic health problems can develop as a result of bio-accumulation of heavy metals such as Cd, Pb, Ni, Cu and Cr in the human body. A study was carried out at the Kwame Nkrumah University of Science and Technology, Ghana using Cd and Pb solutions of 0, 0.05 and 0.1 mg L-1 and 0, 30 and 50 mg L-1 concentrations respectively to irrigate cabbage, carrots and lettuce. Kinetics of Cd and Pb concentrations in irrigation water were studied. The study results showed that release of metals in soils was non-linear resulting in variation in the metal distribution coefficient. Laboratory analysis results showed a reduction in the yields of lettuce by 11 and 16% for the treatments with Cd concentrations of 0.05 and 0.1 mg Cd L-1 in irrigation water respectively, compared with yields from the control treatment (0 mg Cd L-1 in irrigation water. On the other hand, there were increases of 61 and 53%, respectively in yields of carrots irrigated with water containing 0.05 and 0.1 mg Cd L-1.