Determination and Evaluation of the Heavy Metal Pollution in Obajana Industrial Belt, Central Nigeria

Abstract

The Obajana industrial belt is a predominantly mineral rich area where cement production with attendant 
environmental pollution with heavy metals is occurring. The extent of heavy metal pollution on the 
agricultural soil from this industrial area was carried out using Flame Atomic Absorption Spectrometric 
technique. The results of heavy metals from the soil indicated that Cr and Ni have elevated concentrations 
as the distance from the factory is increased with the values 0.52 – 6.06 mg/kg and 0.05 – 3.35 mg/kg 
respectively. For Fe, Cu and Cd, the concentrations reduced as the distance from factory is increased with 
the value ranging from 1.20 – 4.90 mg/kg, 0.24 – 0.74 mg/kg and 0.09 - 0.59 mg/kg respectively. The geo 
accumulation index analysis indicated that the soil Cr, Cu, Cd, Mg and K are unpolluted to moderately 
polluted, Fe and Na are moderately to strongly polluted. Zn and Ni were observed to be very strongly 
polluted. This high content of Zn and Ni may plausibly come as a result of the industrial emissions from 
the mineral rich soil. The soils around the Obajana industrial belt are not fit for agricultural purpose due to 
the objectionable increase in the levels of some of the heavy metals.