Health risk assessment of heavy metals in Manihot esculenta leaves cultivated in a polluted area of Kabwe District, Zambia

This study carried out in Makululu Township, Kabwe, Zambia, a former mining town, assessed health risks from heavy metal (HM) contaminated Manihot esculenta (cassava) leaves. Using ICP-OES, researchers found several HMs exceeded maximum permissible limits (MPLs), including significantly elevated levels of aluminium (Al), barium (Ba), manganese (Mn) and zinc (Zn). While lead (Pb) approached its MPL, arsenic (As) and cadmium (Cd) were undetected. The calculated Hazard Index (HI) of 1290.25 indicated substantial non-cancer risk from combined metal exposure and a combined carcinogenic risk (Σ CR) of 0.0013 are concerning. Furthermore, a composite soil sample (pH 7.855) from the same area showed elevated levels of several potentially toxic metals (PTMs). These findings emphasize the urgent need for continuous monitoring of cassava leaf consumption and highlight severe probable health hazards from dietary HM exposure for Makululu Township residents. Targeted public health initiatives, appropriate remedial as well as agronomic measures are crucial.