Evaluation of Heavy Metal Concentration in Maize Grown in Selected Industrial Areas of Ogun State and its Effects on Urban Food Security

摘要

This project was carried out to investigate the effect industrial pollution as it affects the heavy metal concentrations flared into the atmosphere, washed down by rain and absorb by maize cultivated in industrial areas of Ogun State. This was suspected to have effects on food safety .In addition to determine the effect of soil factor and the accumulation of metals in maize. This study also ascertained the basis for environmental protection and reduction of the negative implication of heavy metals in the human and livestock health. Maize and soil samples were collected from industrial areas in Ogun State and were analyzed for both chemical and metal concentrations. The metals Fe, Cu, Mg, Ni, Pb, Ca, and Co were determined using Atomic Absorption Spectrophotometer (AAS). The results of the chemical analysis of the maize collected from the industrial areas of Ogun State ranged between 6.35-9.45%, 8.31-12.68%, 1.49-8.294% 1.746-2.792%, and 71.32-78.896% for moisture, crude protein, ether extract, and carbohydrate respectively while the chemical analysis of the soil ranged between 0.65-1.90%, 6.63-7.89%, and 4.01-8.6% for moisture, pH, and nitrogen content respectively. The concentrations of the metals Fe, Cu, Mg, Ni, Pb, Ca, and Co in maize ranged between 28.5-59.5mg/kg, 2-10.7mg/kg, 248.3-321mg/kg, 1.8-4.775mg/kg, 62.5-150mg/kg, and 1.2-10.2mg/kg respectively while the concentrations of the soil samples were 28.9-59.6mg/kg, 4-12.2mg/kg, 297.3-350.5mg/kg, 4.55-9.28mg/kg, 83.3-177.5mg/kg, 7.6-21.8mg/kg, and 0.075-0.46mg/kg for Fe, Cu, Mg, Ni, Pb, Ca, and Co respectively. Some of the metals such as Ni in Ewekoro, Pb in Sango, exceeded the recommended limits proposed by WHO/FAO. The results showed that the high concentrations of certain heavy metals in maize revealed the level of food insecurity and this calls for public concern.