HEAVY METAL CONCENTRATION OF SURFACE DUST PRESENT IN E- WASTE COMPONENTS: THE WESTMINISTER ELECTRONIC MARKET, LAGOS CASE STUDY

Abstract

To evaluate the extent of heavy metals (Cd, Cr, Pb, Zn, Fe) contamination from e-waste, surface dust samples were collected from workshops (indoor), around the market areas (outdoor) and from a distance of about 100 metres away from the market area (control) of the Westminister Electronic market in Lagos, Nigeria. Aqua regia digestion was applied to the dust samples prior to determination of heavy metal by atomic absorption spectroscopy (AAS). The AAS analysis revealed mean concentrations in indoor dust (Pb 22.50, Cd 1.80, Fe 108.00, Cr 0.35 and Zn 295.50 mg/kg), outdoor dust (Pb 15.90, Cd 19.00, Fe 103.3, Cr 0.10 and Zn 213.00 mg/kg) and control dust ( Pb 9.40, Cd -, Fe 62.00, Cr - and Zn 78.00 mg/kg). Although the result showed a relatively low contamination in general, it could be inferred that the increased con- centration of heavy metals from the indoor electronic waste could be from the interaction of heavy metals in the e-waste components with the settled dust on them over time. Risk assessment predicted that Cd and Zn in the e-waste have the po- tential to pose serious health risks to workers, customers and local residents of Westminister area, especially children, and this underscores the urgent intervention by relevant government agencies.