TITLE:
Heavy Metal Pollution of Topsoil in the Vicinity of an Industrial Estate Co-Located with a Housing Estate in Southwestern Nigeria
AUTHORS:
Effiong Ukorebi Etim, Percy Chuks Onianwa
KEYWORDS:
Heavy Metal; Soil Contamination; Industrial Estate; Industrial Waste Dumpsite
JOURNAL NAME:
Journal of Environmental Protection,
Vol.4 No.1,
January
29,
2013
ABSTRACT: Heavy metals were determined in
topsoils around a major industrial estate co-located with a housing estate in
the southwestern region of Nigerian. Samples were collected on three-monthly
basis for 18 months, from the industrial waste dumpsites, industrial area,
residential area, around an effluent channel, outskirts of the estate and
control sites. Average levels of Cu (2850 ± 3340 mg/kg), Pb (768 ± 450 mg/kg) and Ni (105 ± 30 mg/kg) at the dumpsites were significantly
higher than other locations. At the industrial area and effluent channels, Pb
and Cr levels were slightly elevated compared with other metals. Metal levels
at the residential area and outskirts of the estate were about the levels in
the control. Generally, the degree of contamination within the vicinity of the
estate was of the order Cu>Pb>Ni>Cd>Co>Cr. Average total
bioavailable (non-residual) fraction of the metals consisted of 52.0% of the
metal load, with this fraction for Cd and Pb being 73.9% and 60.7%
respectively. Topsoils around the dumpsite were evidently polluted with high
levels of copper and lead. Seepage of leachate from the dumpsite has the
potential of contaminating ground water reserves. Improper disposal of
industrial solid wastes appears to be the likely source of metal pollution in
the industrial estate. Heavy metal pollution in the estate can therefore be
significantly reduced by prompt and proper disposal of generated solid wastes,
and the application of particulate scrubbers in the industries.