Monitoring and Statistical Evaluation of Heavy Metals in Respirable Dust in Jos Metropolitan Area, Nigeria

Abstract

The concentration of heavy metals in respiration dust (˂10μg) within Jos Metropolis was monitored in seven sites made up of two industrial and high traffic areas each, with residential site as control were studied for nine consecutive months (October, 2013 to June, 2014). The concentrations of the heavy metals were studied in terms dust mass, time dependence and safety. The mass of respirable dust ranged from 0.079 - 0.288g, while the mean concentration ranged from 49 - 208ug/m3. Flame Atomic Absorption Spectrometry (FAAS) analysis shows that the concentrations of heavy metals ranged from Pb, (0.016 - 0.331) mg/kg, Cr, (0.016 - 0.118)mg/kg Fe, (0.012- 0.652) mg/kg, ( 0.07 - 0.056) mg/kg, Cd, (0.002 - 0.107 )mg/kg, Zn, (0.0233 - 0.988) mg/kg, Cu, (0.023 -0.668) mg/kg and Ni (0.004 - 0,058) mg/kg across sites studied. The data obtained were treated statistically using one-way analysis of variance at 95% confidence limit for mean and correlated with the anthropological and industrial activities of the sites. The main sources of these heavy metals in the sampled areas, was attributed to anthropogenic activities like open incineration of waste, vehicular traffic and ongoing construction work within some of the sites.