Heavy metal content of the soil in the vicinity of the united cement factory in Southern Nigeria

Abstract

Cement dust deposition on soil has been implicated in the heavy metal (HM) contamination of soil, leading to adverse effects on plants and humans. This study assessed the impact of cement dust deposition on the HM content of the soil samples in the vicinity of a cement factory and its implication on the public health of the host community. Topsoil samples were collected at varying distances and directions in the vicinity of the cement factory and a remote area to the factory (control). The Pb, Cu, Mn, Fe, Cd, Se, Cr, Zn, and As content of the soil samples were determined by atomic absorption spectrophotometry. The HM content of the soil samples in the studied locations were within the safe limits, except for Zn, which was higher in the samples closest to the factory. The levels of Mn, Fe, Zn, Pb, Cu, and Cr were significantly higher in the samples closest to the factory compared to the other locations (P<0.05). Moderate contamination with Cu and Pb and considerable contamination with Cr were observed in the samples closest to the factory. The HM content of the soil samples of all the locations demonstrated minimal enrichment (EF<2) and average pollution index (1<IPI≤2). Cement production is associated with the exacerbation of the HM contamination of the surrounding soil, with the degree of contamination depending on the distance from the factory. Moderate soil contamination with HM poses potential risk of deleterious public health effects if appropriate remediation strategies are not implemented.

Keywords

• cement dust
• heavy metals
• soil
• contamination