Heavy Metal Contamination in Soils from Urban and Rural Dumpsites of Ebonyi State, Southeastern Nigeria

Abstract

Use of soils around dumpsites in rural and urban areas is common for food production, especially vegetables. However, most people use such soils without knowledge of the risk of heavy metal uptake by plants. Therefore, the assessment of heavy metal contamination is an important component of risk assessment at waste dumpsites. This study was conducted at the Ahiaofu Market dumpsite in Abakaliki and the Emezaka Ngbo market in the Ohaukwu LGA of Ebonyi State to determine the risk of heavy metal pollution of soils at a waste dumpsite. Soil samples were collected from a depth of 0–20 cm. Heavy metals such as lead, zinc, cadmium, chromium, and copper were analyzed using atomic absorption spectrophotometry (AAS). Their concentrations at the two (2) dumpsites generally followed the trend: Concentration of metals in sample A (Ahiaofu Market dumpsite, Abakaliki): Zn > Cu > Pb > Cd > Cr, while the concentration of metals in sample B (Emezaka Ngbo Market in Ohaukwu LGA) is Zn > Cr > Pb > Cu > Cd. The results revealed that the soil samples from the dumpsites were slightly contaminated with Zn, as opposed to the remaining heavy metals (Cr, Cd, Pb and Cu). However, heavy metal contamination at the two dumpsites was within the permissible limits recommended by FAO/WHO. There is a need for regular monitoring and decontamination of the dumpsite before use for agricultural activities. At 100 and 150 mg/kg body weight, histopathological plates show that rats in groups II and III were tolerant to E. senegalensis leaf extract