ABSTRACT
The proliferation of dismantling and scrapyards in Benin City are a menace to the environment and pose potential health risk to nearby residents. The aim of this study is to assess the physicochemical properties, heavy metals and microbial counts of soils in scrapyards in Benin City. Soil samples were collected from three sample points between January to March, 2024 to a depth range of 0-15cm using hand dug auger. Physicochemical analyses were carried out using standard analytical methods. The results indicated that all physicochemical parameters at the sample points fall within the acceptable limits set by the World Health Organization (WHO), except for electrical conductivity, which slightly exceeds the recommended threshold. Heavy metal analysis revealed that chromium, iron, and lead levels were within permissible limits, with zinc exceeding limits at sample point 1 only, and cadmium and copper surpassing WHO, Department of Petroleum Resources (DPR) intervention target, and DPR value limits. The contamination indices of the sample points indicated a moderate degree of contamination, with values exceeding 1, while reference sites demonstrated low contamination, with a calculated value of 0.94, less than 1. The Pollution Load Index (PLI) indicated that the scrapyard is polluted, as their soils surpass the critical value of 1.0, while the reference site (SP 2) remains unpolluted. The geo accumulation index (Igeo) for copper, lead, and iron suggested no pollution, while cadmium in scrapyards indicated moderate to severe pollution, contrasting with the slightly polluted reference site. Similarly, Igeo values for copper and zinc showed slight pollution in scrap yards and no pollution in the reference site. The microbial analysis revealed that 3 × 103 cfu/g to 6 × 103 cfu/g were found in the scrapyards sample points and 0 × 103 cfu/g to 1 × 103 cfu/g at the reference site suggestive of microbial contamination at the investigated sample points. I recommend further studies on soil quality assessment in scrapyards, given the proliferation of such activities and regular monitoring by environmental agency.
