ABSTRACT

This study was carried out to determine the level of heavy metals concentration in soil and settled dust samples in four (4) randomly selected auto-mechanic workshops at varying depths 0-5cm, 5-10cm, 10-15cm and 15-20cm respectively. A total of sixteen (16) soils samples were collected in four different mechanic workshops at Afikpo in Afikpo North L.G.A, Ebonyi State. Four control samples were also collected in a primary school which is about 3 to 4km away from the activities of the mechanic workshops. Four (4) settled dust samples were equally randomly collected from abandoned cars packed in the four selected mechanic workshops. The soil samples were analysed for heavy metal concentration, pH and electrical conductivity (EC). Four heavy metals (As, Cd, Hg and Pd) were determined using AAS method. The dust samples were analysed for only heavy metals concentration. The pH of the soils ranged between 4.29 and 5.78 in the mechanic workshops and 4.39 and 5.78 in the control soil, which is below the neutral level of 7.00. The electrical conductivity (EC) ranged between 46.40µscm^-1 and 312.60µscm^-1mechanic workshops and 50.80µscm^-1and 81.00µscm^-1for the control, which shows high conductivity values in the mechanic workshops in comparison with the control which indicates acidity and presences of soluble inorganic salts. Arsenic and Mercury were not detected in all the soil and dust samples from all the mechanic workshops and control. The heavy metal concentration (mg/kg) of Cd ranged from 2.18mg/kg and 97.67mg/kg in the mechanic workshops with the highest at Ndubuise Mechanic workshop (NDMWS). Pb was of higher concentration in all the mechanic workshops with the highest of 276.96mg/kg at Ebiri mechanic workshop (EBMWS). Generally, variations exist in the concentration within mechanic workshops at different depths. Comparison of the results of the mechanic workshops and the control, shows that the mechanic workshops were moderately contaminated (polluted) which may be due to the anthropogenic waste generated from the workshops. The concentration of Cd ranged from 43.63mg/kg to 3.45mg/kg in settled dust samples. Also, the concentration of Pb ranged from 252.21 mg/kg to 105.88 mg/kg. The obtained results indicate various levels of dust pollution by these metals in the mechanic workshops and so calls for concern due to the health implications of these metals.