EVALUATION OF POTENTIAL NON-CARCINOGENIC HEALTH RISKS FROM INGESTION OF HEAVY METALS IN CONTAMINATED SOILS AROUND SAND MINING AREAS

The study assessed the levels of heavy metals in soils near sand mining sites in Iyuku, Auchi, Edo State, Nigeria and evaluated associated non-carcinogenic health risks through incidental ingestion. Soil samples were collected from ten locations, air-dried, sieved and analyzed for Fe, Zn, Cu, Pb, Cd, Mn, Ni, Cr and Co using atomic absorption spectrophotometry after aqua regia digestion. Mean concentrations were highest for Fe (56.24 mg/kg), followed by Zn (27.15 mg/kg) and Cu (18.76 mg/kg), with Cd and Co at trace levels (0.45 mg/kg and 0.32 mg/kg, respectively). All values fell below World Health Organization (WHO, 2011) and United State Environmental Protection Agency (USEPA, 1992) soil quality guidelines, indicating limited contamination. Chronic daily intake (CDI) via ingestion was calculated for children and adults, revealing higher exposure in children due to behavioural factors. Hazard quotients (HQ) for individual metals and the hazard index (HI) for combined exposure were all below 1, suggesting negligible non-carcinogenic risks. However, elevated Fe and Zn near active pits highlight the need for ongoing monitoring. The findings underscore the importance of regulatory measures to prevent future escalation of risks in similar mining communities, emphasizing sustainable practices to protect vulnerable groups.