Abstract
Contamination of the environment by heavy metals is a phenomenon of global importance today. When
present in high concentrations in the environment, heavy metals may enter the food chain from soils
and result in health hazards. This study is aimed at determining the elemental concentrations of heavy
metal pollutants that may be present in street dust samples in Yola, Adamawa State, Nigeria. Dust
samples were collected in mechanical workshops (MWK), motor parks (MPK), market areas (MKA),
roundabouts/highways (RHW) and residential areas (RDA). The dust samples were digested using aqua
regia digestion method and atomic absorption spectrophotometer was used for the elemental analysis.
The variation in concentration of most of the heavy metals determined from different sites decreases in
an order represented as MWK>MPK>MKA>RHW>RDA. The heavy metals showed a variation that
indicated that Fe>>Zn>Pb>As>Cu>Ni>Cr>Cd. Iron had the highest concentration in all the sampling
areas with range of 6460.00 ± 198 - 40500.00 ± 500 µg/g. The lowest value was observed for Cd with
respective range of 0.43 ± 0.05 - 1.54 ± 0.0 6 µg/g. Cobalt and selenium were not detected in all the
samples. Statistical analyses by ANOVA showed a significant difference (P < 0.05) between the
elements determined. This suggested that, the heavy metal pollutants in the street dust samples of Yola
did not originate from common anthropogenic sources. Probably automobile emission, welding of
metal and exhaust from generators may have contributed as one of the major sources of these
elements.
Key words: Metal pollution, dust, sampling sites, automobile emission, atomic absorption spectrophotometer,
toxic substances, concentration.
