Trace Metal Uptake by Food Cultivars in Coal Mining Environment of Enugu State, Nigeria

Abstract

The aftermath of unsustainable artisanal mining operated within three communities (Iva valley, Onyeama and Akwukwe) of Enugu State and it’s environ was investigated. Soil and food crops from the selected communities were analyzed for their heavy metal contents using the Atomic Absorption Spectrometry (AAS). The soil samples in the three communities were found to have a higher concentration of Mn, Cr, Pb, and Cd except for Ni when compared to the control sample taken at Oghu in Udi but lower to the WHO permissible limit in soil and plants. However, the value of Transfer Index Factor across the impacted locations affirms that the pumpkin leaf has a higher loading affinity for manganese and chromium values as 2.63 and 0.33 respectively while Pb in Iva Valley has the highest value at 5.67, Nickel has the least loading in all the food crops in the three communities with an insignificant value. Preferences in metal accumulation in crops and soil at Akwukwe location follows the order of decreasing magnitude of pumpkin>scent leaf>cassava> and Mn>Pb>Cr>Cd>Ni respectively. These results suggest that the pollution of the environment by the heavy metals in these areas were as a result of the coal Mining activity and use of chemical fertilizer by the agrarians, thereby increasing the levels of Mn, Cr, Pb, and Cd, concentrations in the soil and food crops. Selective agronomic techniques are suggestive remedial measure to stem down the bioavailable fractions of these trace metals in terrestrial food chain.