Measures of Harm from Heavy Metal Pollution in Battery Technicians’ Workshop within Ilorin Metropolis, Kwara State, Nigeria

Soil pollution with Heavy Metals (HMs) has been of much interests lately and is one of the major issues to be faced globally and requires attention because heavy metals above their normal ranges are extremely threatened to both biotic and abiotic life. It was therefore of interest to conduct study to assess the extent of heavy-metal contamination of soils within battery technicians’ workshops within Ilorin metropolis, Kwara State, Nigeria. A total of twenty-five composite soil samples were collected from six selected battery charger workshop within Ilorin metropolis and analyzed for the presence of heavy metals using atomic absorption spectrophotometer. Result reveals significant positive relationship between Mn and Fe (r=0.511**, p<0.001), Mn and Cu (r=0.565**, p<0.001), Fe and Cr (r=0.895**, p<0.001), Fe and Cu (r=0.823**, p<0.001) and between Cr and Cu (r=830**, p<0.001). Result also shows significant negative relationship between Mn and Cr (r=-0.679**, p<0.001), Pb and Cu (r=-0.468*, p<0.05) respectively. The pollution status of heavy metals in soils was evaluated using quantitative indices (pollution index–PI). The result shows that Zn was moderately contaminated while other heavy metals (Pb, Cd, Cr and Cu) had very slight contamination (pollution index<0.1). The Ilorin metropolis soils of Kwara State were found to have a moderate to very slight contamination respectively. Large variations in PI values of Zn revealed that soil in those areas of the city, which are influenced by anthropogenic activities, have moderate concentrations of Zn resulting in “considerable risk”. The findings of this study recommend comprehensive continuous annual monitoring and auditing and further studies on the level of these heavy metals in the near future to ascertain long-term effects of anthropogenic impact is forestalled to protect the men and the environment. This should also involve larger coverage with studies on ground water around such locations. Furthermore, continuous metals speciation should be carried out so that the form and extent of metal bioavailability can be evaluated further

Bioaccumulation of Heavy Metals by Clarias gariepinus (African Catfish) in Asa River, Ilorin, Kwara State

Background. Harmful wastes and other dangerous industrial by-products constitute major sources of environmental pollutants in Nigeria. Industrial pollutants discharged into the environment contain organic and inorganic pollutants in dissolved, suspended and insoluble forms. Fishes are known for their innate potential to bioaccumulate heavy metals in their muscles and various organs. Objectives. The present study aimed to assess the bioaccumulation status of heavy metals in selected organs and tissues of African catfish in Asa River, Ilorin, Kwara State, Nigeria. Methods. Three sampling points (A (upstream), B (point of discharge) and C (downstream)) were selected in relation to industrial effluents that enter the river. African catfish were randomly harvested from each site using fishing nets at the three sampling points. The samples were digested and subjected to atomic absorption spectrophotometric analysis. Statistical analysis of data was carried out using the Statistical Package for the Social Sciences (SPSS) version 20 and two-way analysis of variance (ANOVA) to compare data among sites and organs. Results. The present study found that the bioaccumulation level of heavy metals in selected organs and tissues of African catfish in Asa River, Ilorin, Kwara State, Nigeria was very high and the level of accumulation of heavy metals increased downstream. Accumulations were much higher during the dry season (especially in the month of February) and relatively low during the peak of the rainy season. Conclusions. Heavy metals at elevated levels in the aquatic environment can accumulate in fish tissues and organ, and therefore fish from the Asa River are not fit for human consumption. Competing Interests. The authors declare no competing financial interests