CARCINOGENIC

This study evaluated the non-carcinogenic health risks associated with dermal exposure to heavy metals chromium (Cr), lead (Pb) and zinc (Zn) in groundwater from Ikpeshi, Edo State, Nigeria. The research aimed to quantify metal concentrations, assess health risks across population groups, identify contamination sources and propose mitigation strategies. Groundwater samples were analyzed and risk assessment models were applied using Chronic Daily Intake (CDI), Hazard Quotient (HQ) and Hazard Index (HI) frameworks as outlined by the United States Environmental Protection Agency (USEPA, 2004). Results revealed that chromium exhibited the highest mean concentration (0.177 mg/L), followed by zinc (0.257 mg/L) and lead (0.016 mg/L). Both Cr and Pb levels exceeded the permissible limits set by the World Health Organization (WHO, 2017) and USEPA, primarily due to artisanal and small-scale mining, mine tailings leaching and oxidation of metal-bearing minerals within the Igarra schist belt. Risk assessment outcomes indicated that children are more vulnerable to dermal exposure than adults, given their higher skin surface area-to-body weight ratio and frequent water contact. Chromium was identified as the dominant contributor to non-carcinogenic risks, followed by lead, while zinc showed minimal contribution. Some HI values for children exceeded unity, indicating potential chronic health effects and the mean carcinogenic risk (CR) for Cr approached the USEPA threshold of 1 × 10⁻⁴. The study concludes that chromium and lead pose significant public health concerns in Ikpeshi groundwater. The findings emphasize the need for effective groundwater monitoring, regulation of mining effluents and community-based mitigation strategies such as the use of affordable household filtration systems, rainwater harvesting and public health education to reduce dermal exposure risks and safeguard water quality.