ASSESSMENT OF SELECTED HEAVY METALS FROM KOFAR RUWA AUTOMOBILE MECHANIC WORKSHOP SOIL

Abstract

Heavy metal contamination of soils has become a major environmental concern due to its potential risk to human health and the ecosystem. This study assessed the levels of selected heavy metals Zn, Fe, Pb, and Cu in soils collected from the automobile mechanic Kofar Ruwa, Kano, Nigeria. Physicochemical parameters such as pH, electrical conductivity, total dissolved solids, soil texture, and organic carbon were tested. Heavy metals were extracted using acid digestion (aqua regia method) and quantified using Atomic Absorption Spectrophotometry (AAS). The results revealed variations in both physicochemical parameters and heavy metal concentrations across the sampling sites. pH values ranged from slightly acidic to neutral (8.04), while EC (1815 uS/cm) and TDS indicated moderate levels of soluble salts in soils influenced by anthropogenic activities. Zn (3.45±0.0012 mg/kg) and Fe (31.58±0.095 mg/kg) concentrations were relatively high in areas near metal workshops, whereas Pb (13.89±3.14 mg/kg) showed elevated levels near refuse dumps, highlighting potential sources of contamination. Correlation analysis indicated significant relationships between heavy metal concentrations and soil physicochemical properties, suggesting that soil pH, organic matter content, and texture influenced metal availability and mobility. The study concludes that human activities significantly contribute to heavy metal accumulation in the soils of the Kofar Ruwa automobile mechanic workshop, with potential environmental and health implications.