Assessing The Carcinogenic And Non-Carcinogenic Health Risk Of Heavy Metal Contamination In Soils From Ratcon Quarry Site In Ibadan, Sw Nigeria

Abstract

This study estimates the health risks due to the concentration of heavy metals in the soil samples around a quarry near Ibadan, Nigeria. Soil samples were collected in triplicates (three samples collected per sampling point) from ten sampling points in the quarry site and control.

The soil samples were digested for 17 heavy metals (Al, As, Co, Cd, Cr, Cu, Fe, Hg, Mn, Mo, Pb, Sb, Se, Sn, V, and Zn) and quantified using Inductively Coupled Plasma- Optical Emission Spectrometry)- (ICP-OES). Health risk was assessed for metals including hazard quotient (HQ), hazard index (HI) and cancer risk (CR). Data obtained were subjected to descriptive (Mean ±SD) and inferential (Anova) statistics. Results showed that 16 heavy metals were detected, Fe had highest concentration (4354±17.4 mg/kg), followed by Al (1678 ±0.15 mg/kg) and Mn (192±1.29 mg/kg), Cd was not detected. The estimation of non-carcinogenic risks in this study indicated that all identified heavy metals in soils do not pose a non-carcinogenic risk to the health of children and adults.  Hazard quotient (HQ) and hazard index (HI) values consistently were less than one (< 1). Also, this study revealed that values of most metals assessed were below 1 × 10^-6 lower limit for CR, except for chromium (1.97 X 10^-1), which poses a cancer risk in adults.