Determination of heavy metal pollutants in street dust of Yola, Adamawa State, Nigeria

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.