Analysis of heavy metal concentration in auto-mechanic dumpsites in Makurdi Metropolis, North Central Nigeria

Abstract

This research was carried out to assess heavy metals pollution in Makurdi auto-mechanic dumpsites in Kanshio (K), Northbank (NB) and Wadata (W). Atomic absorption spectrophotometer (PG990) was used to determine the heavy metals concentration. Results of the mean heavy metals concentrations (Cd, Cu, Pb and Zn) were found to be K (4.65, 137.12, 257.77 and 294.75), NB (1.97, 65.67, 162.88 and 223.23), and W (2.92, 85.27, 187.20 and 262.00 mg/kg), respectively, they were higher than their referenced maximum permissible level in the soil when compared to World Health Organization (WHO), United States Environmental Protection Agency (USEPA), Mean Shale Concentration (MSC) and World Surface Rock Average (WSRA) guidelines, indicating high level pollution. The high level of Cu, Pb and Zn, may be due to waste from welding activities, lead (Pb) battery repairs and coatings done in these area. The geo-accumulation index for Cd and Pb for the three dumpsites was found to exhibit moderately to strongly polluted character with values within 2-3, while Cu and Zn were from uncontaminated to moderately contaminated with values 1. Key words: Heavy metals, auto-mechanic dumpsite, geo-accumulation index, contamination factor and pollution load index.