Assessment of heavy metal contamination and health risks in groundwater of Abakaliki Metropolis, Nigeria

Abstract This study aimed to assess the human health risks associated with groundwater consumption in Abakaliki Metropolis using Water Quality Index (WQI) and HERisk code. Groundwater samples (n = 32) obtained from boreholes were analysed for pH, Zn, Pb. Fe, Cr and NO3 to evaluate both non-carcinogenic and carcinogenic health risks. The average concentrations of these parameters, except Pb (0.02 mg/L) and Cr (0.06 mg/L), were within permissible limits. The distribution of the average concentrations of the parameters followed the order: Zn > Cr > Fe > NO3 > Pb. The WQI ranged from 0.15 to 505.67 classifying 12.50% of the water samples as excellent sources of drinking water, 9.38% as good, 9.38% as poor, 12.50% as very poor and 56.25% unfit for drinking. The HERisk code revealed significant non-carcinogenic and carcinogenic health risks exceeding safety limits (