Distribution, sources and risk assessment of metals in dusts from automobile mechanic workshops in Nigeria

Abstract

This study investigated the concentrations of nine metals such as Cd, Pb, Cr, Ni Cu, Co, Mn, Zn and Fe in dusts from automobile mechanic workshops (AMWs) in the Niger Delta, Nigeria. Samples of dusts were digestion with aqua-regia and analyzed for metals using atomic absorption spectrometry. The levels of metals in the AMW dusts (mg kg− 1) were 0.12 to 4.20 for Cd, 11.3 to 3897 for Pb, 9.05 to 45.3 for Cr, 0.35 to 345 for Ni, 170 to 56390 for Cu, 1.05 to 31.4 for Co, 51.3 to 310 for Mn, 143 to 634 for Zn and 70875 to 258013 for Fe. Metal distribution patterns in dusts from AMWs followed the sequence; Fe > > Cu > Zn > Mn > Pb > Cu > Ni > Co > Cd. The indices for pollution assessment indicated that Cd, Cu, Pb and Zn were the top contaminants in the AMW dusts. The hazard index values obtained for children’s exposure to metal laden dusts from these AMWs were above 1 which implies that children exposure to dusts from AMWs could elicit adverse non-carcinogenic heath effects. The carcinogenic risk values obtained for human exposure to metals in these AMW dusts were above safe levels indicating possibility of inducing cancer or cancer related sickness. The sources of metals in dusts from the AMWs are related to automobiles emissions and discharges from vehicular components.