Assessment of Potential Ecological Risk of Heavy Metals in Soils from Waste Dumpsites in Military Formations in Makurdi, Nigeria ()
ABSTRACT
Chemical
fractionation of toxic metals (As, Cd and Zn) along the soil profile at waste
dumpsites in military formations for dry and wet seasons using Tessier’s
sequential extraction procedure was determined
using AAS techniques. The order of yield across the fractions was mainly: exchangeable (F1) < carbonate-bound (F2) < Fe/Mn oxide-bound (F3) < organic matter-bound (F4) < residual (F5). Statistical analysis
(p < 0.05) indicated that there was no significant variation between the
values of results obtained from dumpsites A and B of each sampling station.
However, the variation between the dumpsites and control was significant (p > 0.05) in most stations. The pollution index was
assessed using the degree of contamination (Cd), the modified degree
of contamination (mCd), potential ecological risk and mobility
factor. The Cd indicated that NFB top soil was considerably
contaminated (16.3) while the soils (20 - 40 and 40 - 80 cm) recorded moderate (13.6)
and low (5.60) contaminations respectively. Top soil of NSM was moderately
contaminated while the contamination status of NPS, NFB and SFB waste dump
soils across the depths was “low”. The mCd index for NFB dump soil
was “moderate” (2.33) and subsoils (20 - 40 and 40 - 80 cm) were “low” (1.94) and “Nil to very low” (0.800) respectively. The
mCd for the other three dumpsites was “Nil to very low” except the
top soil of NSM which was “low”. The order of the toxic metals mobility in the
studied soils using the Mobility factor (Mf) for dry and wet seasons
was Cd > As > Zn and Zn > Cd > As respectively.
Share and Cite:
Nwankwo, R. , Tongu, S. , Eneji, I. , Nnamonu, L. , Wuana, R. and Sha’Ato, R. (2019) Assessment of Potential Ecological Risk of Heavy Metals in Soils from Waste Dumpsites in Military Formations in Makurdi, Nigeria.
Journal of Environmental Protection,
10, 514-531. doi:
10.4236/jep.2019.104030.