Assessment of heavy metal concentrations in Mango fruits grown in Kasese district, Uganda

Abstract

Fruits are a good source of carbohydrates, sugars, dietary fiber, fat, proteins, vitamins and minerals. In this study, mango fruits grown in Kasese as well as the soil and irrigation water used in fruit growing were analysed for heavy metals cadmium (Cd), chromium (Cr) and lead (Pb). The mango fruits and soil samples were obtained from three sites; Mubuku Irrigation Scheme, Mpondwe-Lhubiriha Town Council (MLTC) and Nyakiyumbu Sub-County in Kasese district. The concentration of Cd was below detection levels in all samples of soil, irrigation water and mango fruits. The mean concentrations of Pb and Cr in the mango fruits was 0.32 ±0.08 and 0.4±0.07 mg/kg dry weight while in soil were 69.98 ± 4.24 mg/kg and 13.403±2.03 mg/kg respectively and that in irrigation water were 0.1127± 0.014 mg/L and 0.0171 ± 0.003 mg/L respectively. The concentration of Pb in mango fruits and in irrigation water was above the maximum permissible limits (MPL) while Pb in soil and Cr in all study matrices were within the MPL by WHO and Dutch standards. These findings suggest that in general, mango fruits grown in Kasese as well as irrigation water have high concentration of Pb and may be a health risk to consumers.   Key words: Heavy metals, Mango fruits, soil, irrigation water, Kasese, Uganda.