Concentration Levels and the Associated Health Risks of Elements in Food Crops Grown in the Neighbourhood of Minjingu Phosphate Mine, Tanzania

The concentration levels of heavy metals in food crops (maize and mung beans) grown in the neighbourhood of Minjingu Phosphate mine were analyzed using EDXRF. The metal concentrations in both food crops followed the following pattern Fe > Zn > Cu > Cd > Cr > Pb > As. Maize accumulated higher levels of all analyzed elements than mung beans. The concentration level of metals in maize and mung beans from Minjingu were higher than those from the control site. Except for Cd in both types of samples, the concentration levels of all other metals were below the FAO/WHO recommended limits. The risk assessment showed that consumption of mug beans from Minjingu is without any safety risk while there is a risk in consumption of maize due to the concentration of Cd. However, the number of samples was not sufficient enough to make a definite conclusion; therefore, there is need for further analysis to include more data.