Assessment of Human Health Risk for Surface Sediments of Ikpoba River Contaminated by Heavy Metals

Five heavy metals (Cu, Pb, Ni, Cd, Fe) were accessed in surface sediments from Ikpoba River in Benin City, South of Nigeria; an area impacted by soil erosion and the Benin Water Storm project. The heavy metals were analysed using atomic absorption spectrometer. The mean concentrations of heavy metals were 0.543 mg/kg (Pb), 1.289 mg/kg (Ni), 0.001 mg/kg (Cd), 18.90143 mg/kg (Cu) and 1022 mg/kg (Fe) respectively. Human health risk assessment was used to assess the pollution degree of the river sediments. The results indicated that the pollution degree of heavy metals increased in the order Fe>Cu>Ni>Pb>Cd. Human health risk assessment indicated that non-carcinogenic risks all fell below threshold level for both children and adults. The total carcinogenic risk due to Pb and Cd were within the acceptable range for both adults and children. The findings provide a scientific basis for the control of potentially toxic heavy metals concentrations and environmental protection of Ikpoba River.