Application of chemometrics and evaluation models for source tracing and risk assessment of heavy metals in soils of Kokompe in Southwestern Ghana

Automobile garages play a crucial role in every country’s transportation industry. However, their unregulated activities, especially in developing countries, pose serious threats to soils. To help realise the United Nations Sustainable Development Goals (especially 3 and 15), this study investigated the spatial distribution, pollution levels, potential sources, and ecological and health threats of heavy metals in soils at Kokompe, an automobile repair hub in Takoradi, Ghana. Fourteen soil samples from 5 sites at different depths were analysed for iron (Fe), chromium (Cr), zinc (Zn), lead (Pb) and manganese (Mn) levels. The concentrations of all heavy metals exceeded the background concentrations in the soils except Mn and Fe, which had a few concentrations below the background values. The average concentrations of heavy metals followed the order: Fe>Zn>Mn>Pb>Cr. The soils were moderately to significantly enriched in Fe, Cr, Mn, and Pb, and were very high to extremely enriched in Zn. Generally, the soils were moderately polluted with Fe, Mn, Pb and Cr, and heavily polluted with Zn, with Zn, Cr, Pb and Mn emanating from anthropogenic sources (automobile wastes) and Fe possibly from both anthropogenic and geogenic sources. The heavy metals pose a low to moderate ecological risk. Based on the health risk assessment, adults were considered safe, whereas children were identified as vulnerable, particularly to non-carcinogenic health risks posed by Cr and Mn. The findings herein are crucial for developing valuable strategies to minimise heavy metal-related risks and enhance long-term ecological sustainability.