Heavy Metals Concentration in Dumpsites at Gwagwalada, Abuja: Implications on Sustainable Environmental Management

Abstract

Agricultural soil quality deterioration resulting from increase in the level of heavy metals is becoming more and more pronounced, thus raising the question of safety status of human health and environment. Heavy metals affect the quality and production of crops and influence atmospheric and water quality. These contamination are important and of concern because of increasing demand for food safety. Heavy metals in two layers (0-15cm and 15- 30cm) of four different sites of waste dumps and the control taken from 50 meters away from the dump sites were studied in Gwagwalada area of Abuja in Federal capital territory of Nigeria. The samples were air-dried and digested with concentrated HNO3 and HClO4 acids; Cu, Pb, Fe, Mo and Zn were determined using an Atomic Absorption Spectrophotometer model Sp 2900. The results showed that the heavy metals were found in the surface soil and the heavy metal levels for the soils follow this trend Fe > Zn > Cu> Mo > Pb. The concentrations of Fe, Zn and Pb were highest in abattoir dumpsite (509.7, 83.8 and 1.5 mg/kg respectively). Cu and Mo were highest in Kuje road dumpsite with (24.1 and 5.5 mg/kg). The study revealed that although the concentrations of the heavy metals were lower than the established limits, they were higher than the control soils. The relatively low average content of the metals investigated in this study present insignificant exposure risks. This does not ruled out the possibility of increase in concentration of these metals with time, since the extent of heavy metal pollution varies with age. The study therefore recommends that dumping of the wastes should stop or more accumulations will constitute a major health risk to the people around these areas.