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.
