Analysis of Soil Heavy Metal Pollution in Automobile Workshops in Nnewi North, Anambra State

Abstract

Heavy metal contamination from activities in automobile workshops is of public health 
concern. These heavy metals can remain in the environment over time. This study examined 
the concentration of soil heavy metal pollution in automobile workshops. To achieve the main 
objective, purposive sampling was adopted and 8 sites were identified of which 5 out of eight 
automobile workshops were selected and another sampling site which has no influence of 
automobile workshop activities was selected as the control. Soil samples from these areas were 
collected at a depth of 0-15cm using a locally fabricated stainless soil auger and a control 
sample was also collected for result comparison. The contamination level of the soil was 
calculated using the geo-accumulation index, the 5-sample site for Cd ranged from 1.6 - 73.93 
mg kg-1,0.84 mg kg-1- 6.39 mg kg- 1 Cu, 0.06 – 5.28 mg kg- 1Pb, 1.16 – 1.99 mg kg-1 Zn, 0.4 – 
2.13 mg kg-1 As, 1.56 – 3.03 mg kg-1Hg. Samples 1,2,3,4,5 indicated a non-contamination level 
for Ni while Zn and As values for sampled site 1, 2, 3 and 4 ranging from 0.4 -2.13 mg kg
1indicate an uncontaminated to moderately contaminated level. One-tailed ANOVA was 
employed to test the statistical difference in the concentration of heavy metals in the sampled 
sites. The result from the statistics showed a p-value of 0.002 which is <0.05. This suggests 
that the different sampled sites contribute differently to the concentration of heavy metals. 
There is a need for strict enforcement of safe waste-handling methods to reduce soil 
contamination around automobile workshops.