EBENEZER OLALEKAN, ADEOLA2024-06-112024-06-112023-12M.Schttps://repository.lcu.edu.ng/handle/123456789/480Heavy metal contamination due to activities in auto-mechanic workshops is of public health concern. In most cities in Nigeria, auto-mechanic workshops are often sited close to residential areas and inhabitants are often exposed to possible health risks arising from heavy metals exposure. This study investigated the physicochemical parameters such as pH, Total Dissolved Solids (TDS), Electrical conductivity, total hardness and concentrations of selected heavy metals (Cu, Cr, Ni, Cd, Mn, Co and Pb) in water and soil samples using standard analytical methods. Samples were collected around some randomly selected auto-mechanic workshops across Ibadan North Local Government (IBNLG) and Ibadan North-East Local Government (IBNELG) Areas of Ibadan. A total of 82 samples comprising 60 soil samples, 20 hand-dug Wells and two (2) control sites were collected from twenty (20) selected auto-mechanic workshops based on the absence of other industries and the presence of dug Wells. Composited (top soil and subsoil) soil samples in three locations and water samples from hand-dug well (0-50 m) around the workshops were collected between October and November 2019. Values obtained were subjected to descriptive (Mean ± SD), correlation statistical analyses and also compared with World Health Organization (WHO) standards and the controls. The pH ranged from 8.18 to 8.40, TDS from 73 to 394 mg L-1, Conductivity from 148 to 790 mg L-1 and Total Hardness from 295 to 300 µS cm−1. Also, the concentrations of Cu, Cr, Ni, Mn and Pb in water samples ranged from ND-1.85, ND-4.13, ND-0.02, 0.02-0.38 and ND-0.84 mg L-1 respectively. Similarly, the concentrations of Cd, Cr, Ni, Cu, Co, Pb and Mn in soil samples ranged from ND to 0.15 to 1.86, 0.04 to 0.37, 0.01 to 2.47, ND to 0.79, 0.81 to 32.6 and 0.10 to 8.73 mg kg -1 respectively. Based on the result of this study, carcinogenic and non-carcinogenic risk factor over a lifetime of exposure through contaminated water and soil are below the tolerable value of lifetime carcinogenic risk set by USEPA (10 -5), indicating that the contact with the soil might not pose carcinogenic and non-carcinogenic risk. Keywords: Heavy metal, auto-mechanic workshop, Health Risk, Carcinogenic. Word Count: 292enHeavy metalauto-mechanic workshopHealth RiskCarcinogenic.Thesis