Surface and sub-surface soils were sampled in the neighbourhood environment of an ultra-modern andudlargest cement factory in Nigeria. The five geochemical fractions investigated were exchangeable,udcarbonate, Fe-Mn oxide, organic matter and residual. All fractions were subsequently analyzed for leadud(Pb), copper (Cu), zinc (Zn), manganese (Mn) and iron (Fe) using atomic absorption spectrophotometer.udThe average total metals concentrations (mg/Kg) in the surface soil were 1063.8± 261 for Fe, 30.29 ±ud19.25 for Mn, 24.15 ± 21.69 for Cu, 15.08 ± 11.95 for Pb and 8.54 ± 3.18 for Zn. Relatively lower meanudconcentrations were measured in the sub-surface soil samples. The percent distribution concentration ofudthe various metals in the residual fraction ranged from 0.23 to 69.48% for Pb, 0.85 to 75.30% for Cu,ud36.02 to 83.86% for Zn, 12.97 to 44.04% for Mn and 18.11 to 57.25% for Fe. Factor analysis revealed thatudwhile Pb, Cu and Zn would majorly be of anthropogenic origin, Mn and Fe are mainly of natural origin. Pbudwas found to be the most mobile with mobility factor of 71.8% while Fe has the least mobility factor ofud3.62%. Regression analysis (r2 = 0.71) further showed that Cu is correlated with Pb. Soil pollution indicesudrevealed that the surface soil is slightly contaminated in lead and zinc, and moderately contaminated inudcopper.
展开▼
