The level of heavy metals (Fe, Cu, As, Pb, Cd, Mg, Ca, Hg, Ni, Cr, Zn, Ag, Co, Mo, Se and Al) in soils and food crops (okra, cassava and rice) cultivated within selected mining sites in Ebonyi State, Nigeria were determined using FS240AA Atomic Absorption Spectrophotometer (AAS) according to the method of American Public Health Association (APHA). Soil samples were collected from Enyigba mining site, Ikwo mining site, AmeriAmekamining site, Izza mining site, MkpumeAkwatakwa mining site and MpumeAkwaokuku mining site while the food crop samples (okra, cassava and rice) were collected from the farmlands within the mining sites. Control samples were collected 500m away from the mining destinations were there was no evidence of mining activities on the soils. A total of sixty sub-samples and six control soil samples were collected for this study. Generally, the values of all the heavy metals analyzed for soil and food crop samples were higher than the values recommended by the World Health Organization (WHO), and those from the control site suggesting possible mobility of the metals from mining sites to farmlands through leaching and runoffs. The findings in this study also revealed that the food crops contain heavy metals exceeding the maximum permissible concentration, and could be detrimental to human health when they are consumed.
Identifying the potential of some heavy metals toxicity in urban and peri-urban cropping systems in Sierra Leone
