ABSTRACT
Iron and Steel industries has been a major contributor of toxic concentration of heavy metal substances into our environment causing harm to man and soil especially. This research was carried out to know the effect of steel industry on soils in Aladja and Environs. Soil samples were taken round the steel plant across communities surrounding it, which include Ovwian community, Warri community and Aladja community. Twenty nine (29) soil samples were analyzed to determine the concentration of some heavy metals which include (Zn, Cu, Fe, Mn, Pb, Cd, & Cr) and Physiochemical parameters such as pH, TOC, and TOM including soil texture of the different soil samples. The soil samples were analyzed with the atomic Absorption Spectrophotometer (A.A.S); results of their different level of concentration were tabulated. Descriptive analysis of the samples was computed using the Microsoft Excel 2010, as well as the analysis of variance (ANOVA) to test for homogeneity. The test showed that there was a statistical difference between the values or data of the soil samples revealing the effect size of difference across the soil data to be 0.99%. The mean concentration and standard deviation of the heavy metals showed: Cu (52.5±67.8), Fe (3249±281), Zn (46±22.7), Mn (35.8±39.3), Pb (70.5±36.3), Cd (14.1±4.7), and Cr (12±5.2). The results showed the concentration level of Fe to be higher across other heavy metals in the soil samples. Different statistical plots were computed to know the existing relationship between the Physiochemical Parameters and concentration of the heavy metals. The rating level of the soil using the pH value rated eleven (11) soils close to the steel plant to be acidic, thirteen (13) basic or alkaline and four (4) normal, indicating the mobility of heavy metals in the soil which may have been contributed by anthropogenic activities such as industrial companies, with little or no natural events (weathering and soil erosion). The soil Samples from the study area was correlated with the control point and the result showed the concentration of heavy metals in the study area to be higher than those of the control point. Soil samples from Aladja Community were used to correlate separately those from Ovwian and Warri communities. The correlation between Aladja and Ovwian soil samples revealed Aladja soil samples to be more concentrated in heavy metals than those in Ovwian. Three order of concentration level were considered and Aladja soil samples showed highest level of concentration of most heavy metals. The result showed more soil samples in Aladja and Dumpsite to have high level of concentration in Cu, Pb Cr Mn Cd & Fe than those from Warri community and Ovwian community. This test and correlation result stands in support of previous work on the effect of steel production in quality of soil around udu section river, that has been carried out in the area, the results shows which that soils or areas located near steel industries are more contaminated than those afar, therefore the primary factor or source of these level of heavy metal concentrations must have proceeded from the outdoors of the steel plant through industrial influents, wastewaters from the subway, emissions of fumes during production and dumping of solid waste (slags) on soil. Moreover, previous work has shown high level of (Zn, Cu, Mn, Pb) as markers of steel smelting. However when these heavy metals may possible exceed their permissible limit, indicating unhealthy condition for soil around the steel plant which is not healthy for agricultural activities for both plants and animal grazing. To remedy this, Steel plants should be located or sited far from human settlements and integrated solid waste management techniques should be applied to litigate toxic metal loads in waste. Soil texture and test for porosity and permeability of soil should be experimentally carried out carefully before disposal of waste.
