Crop uptake of heavy metals in response to the environment and agronomic practices on land near mine tailings in the Zambian Copperbelt Province

A field experiment was undertaken on farmers’ fields adjacent to a large mine tailings dam in the Zambian mining town of Kitwe. Experimental plots were located close (? 200 m) or further away (300–400 within demarcated land farmed by same community. This study evaluated uptake Cd, Cu, Ni, Pb and Zn pumpkin leaves maize grown soil amended with lime manure applied at agronomic rates, subsequent risk dietary exposure local community, typical many similar situations across Copperbelt. Treatments, combinations (present absent), subplots selected independently randomly each main plot, which represented variable geochemistry this site as result windblown/rain-driven dust from tailings. Total elemental concentrations crops determined ICP-MS following microwave-assisted acid digestion. Concentrations Cu above prescribed FAO/WHO safe limits 60–205% 33–133%, respectively, while all five metals below limit for grain. Concentration grain not affected amendments. However, application rates significantly reduced 40%, 33%, 19% 10%, Cd 16%, increased 35%. The locations greater than closer because retention higher pH Crops season 2 had 1 due diminished only 1, line common applications biannual basis. Maize staple crop is grow area readily available commonly consumed leafy vegetable may present hazard accumulation recommended limits.