This study assessed the effect of heavy metals introduced into the soils through human activities which can bio-accumulate in plants and passed to man via the food chain that can pose health risk. Topsoil samples were collected from selected anthropogenic and control sites (dumpsites, mechanical workshops, abattoirs, fuel filling stations and hospital incinerators) in Abeokuta, Nigeria at the depths 0-5cm, 5-10cm and 10-15cm. Physicochemical parameters such as pH, moisture content, bulk density, organic matter, organic carbon, particle size distribution and Mn, Zn, Pb, and Cd were analyzed in soils using standard methods. Soil pH values ranged from 5.17 -8.28, moisture content ranged from 3.50 -28.55 %, bulk density ranged from 0.78 -2.29 gcm -3 , organic matter ranged from 0.09 -16.01 %, organic carbon ranged from 0.02 % -8.48 %. Mean concentrations of heavy metals (mgkg -1 ) ranged from 182.69 ± 61. 95 -697.06 ± 85.62; 122.69 ± 30.04 -632.94 ± 508.79; 19.38 ± 6.72 -158.50 ± 71.41; 0.25 ± 0.00 -1.63 ± 1.38 for Mn, Zn, Pb and Cd respectively. Distribution pattern of heavy metals in petrol stations, abattoirs, mechanic workshops and hospital incinerator sites were Mn > Zn > Pb > Cd, while for dumpsites Zn > Mn > Pb > Cd. Pollution index indicated that soil qualities varied between slightly contaminated to severely polluted status. This showed that the heavy metal contamination of the soils does not call for any alarm; proactive measures must be taken to minimize accumulation of these metals. ©JASEM https://dx.doi.org/10.4314/jasem.v21i5.14

Abstract:This paper presents the characteristic thermal and chemical properties of some surface soil samples from the oil-producing regions of Nigeria. A microprocessor-based thermal analyzer was used to determine the thermal conductivity while spectrophotometric procedure was employed to conduct the heavy metal concentration analysis. Thermal conductivity values were compared with heavy metal concentrations in each soil sample. The values of lead and cadmium and their respective measured thermal conductivities were highly correlated, with their correlation coefficients both greater than 0.900, while other metals showed no correlation.

ABSTRACT:The effect of Inorganic Fertilizer (IF) on the microbial degradation of diesel polluted soil in Abeokuta was assessed by collecting Top soil (0 -15 cm depth) from diesel polluted site