This study assessed the levels of potential toxic element contamination in groundwater near the Ikhueniro and Otofure dumpsites in Benin City, Edo State, Nigeria, and the associated health risks. Water samples were collected from boreholes in residential areas surrounding both dumpsites during both the rainy and dry seasons, yielding 144 samples. The samples were analyzed for lead (Pb), cadmium (Cd), chromium (Cr), zinc (Zn), iron (Fe), nickel (Ni), and copper (Cu) using standard protocols. The results indicated that Fe (1.065 ± 0.340), Cu (0.532 ± 0.055), Zn (0.665 ± 0.384), and Ni (0.028 ± 0.023) were the most prevalent metals, with Fe showing the highest concentrations at both sites. The hazard index (HI) and cancer risk (CR) calculations highlighted serious health risks, particularly for children and infants. At Ikheniro, the HI values were 2.97 mg/kg/day for children and 4.45 mg/kg/day for infants, while at Otofure, the HI values were 2.21 mg/kg/day for children and 2.76 mg/kg/day for infants, all exceeding the safety threshold of 1 mg/kg/day, indicating significant non-carcinogenic health risks. For cancer risk (CR), the cumulative values for chromium (Cr) and nickel (Ni) ranged from 0.00071 mg/kg/day to 0.00077 mg/kg/day in adults, 0.00213 mg/kg/day to 0.00231 mg/kg/day in children, and 0.00267 mg/kg/day to 0.00289 mg/kg/day in infants at Otofure, surpassing the acceptable lifetime risk level of 1 × 10⁻4 mg/kg/day. Similarly, at Ikheniro, the CR for Cr and Ni in children were 0.00110 mg/kg/day and 0.00214 mg/kg/day, respectively, while the CR values for Cr and Ni in infants reached 0.00196 mg/kg/day and 0.00321 mg/kg/day, respectively. These results indicate a significant potential for long-term health impacts, especially among vulnerable populations. The study concluded that the proximity to these dumpsites significantly deteriorates groundwater quality, emphasizing the need for stricter environmental controls and public health interventions.
Asemota et al. (Tue,) studied this question.