Heavy metal contamination of selected mining fields in North-Central Nigeria

This study evaluates the causes, concentration and the associated health risks of selected heavy metals (HMs) in soil samples collected from beryllium and gold mining fields in Nigeria. The samples of soil were collected manually and analysed by means of Atomic Absorption Spec-trophotometry (AAS). Seventy-two (72) samples were analysed which presented varying degrees of concentration of the selected HMs. The analysed HMs are Chromium (Cr), Arsenic (As), Iron (Fe), Cadmium (Cd), Nickel (Ni), Manganese (Mn), Magnesium (Mg), Zinc (Zn), Copper (Cu) and Lead (Pb). Deterministic and stochastic approaches were explore to examine the human health risks. The evaluated Hazard Indices (HI) for the investigated mining locations are < 1, the rec-ommended threshold provided by United State Environmental Protection Agency (USEPA) for acceptable non-cancer risk. The estimated cancer risk levels for the mining locations exceeds the acceptable range of 1.00E-6 and 1.00E-4. center dot Thus, the mining is making significant contribution to HMs pollution, which is dangerous human health. center dot However, the Monte Carlo simulation (MCS) reveals that the 95th, 50th and 5th percentiles of the cumulative probability of the cancer risks are within the acceptable range. center dot This work will be useful for decision makers in mitigating heavy metals contamination due to mining activities.