Heavy Metals Concentration at Electronic-Waste Dismantling Sites and Dumpsites in Lagos, Nigeria

The importation and refurbishing of second-hand electrical and electronic equipment (EEE) is a major concern all over the world and Nigeria is not in exception owing to the generation of e-wastes. The assessment of the levels of Pb, Cr, Ni, Cd and Zn in the dust at dismantling sites and soil from dumpsites in Lagos municipal was performed using Atomic Absorption Spectroscopy. Control samples were also taken at 1km away from each site. At the dismantling sites, the concentration of Pb, Cr, Ni, Cd and Zn were found to range between 99.63 to 141.90 mg/kg, 14.80 to 21.88 mg/kg, 30.41 to 55.68 mg/kg, 10.55 to 23.56 mg/kg and 57.61 to 111.48 mg/kg, while that of the control site ranged between 44.31 to 73.33 mg/kg, 6.62 to 13.42 mg/kg, 16.44 to 34.13 mg/kg, 5.86 to 14.40 mg/kg and 20.35 to 60.73 mg/kg respectively. At the dumpsites, the contents of Pb, Cr, Ni, Cd and Zn were found to range between 152.30 to 328.40 mg/kg, 23.94 to 30.80 mg/kg, 53.75 to 64.81 mg/kg, 24.86 to 31.40 mg/kg and from 211.46 to 306.94 mg/kg, while that at the control sites range between 74.60 to 162.90 mg/kg, 11.43 to 16.52 mg/kg, 36.91 to 41.43 mg/kg, 10.91 to 20.84 mg/kg and 116.90 to 178.31 mg/kg respectively. Heavy metals concentrations at the dumpsites were found to be higher than what was observed in the dust samples at the dismantling sites. Also, the control samples showed lower concentration when compared with the dismantling sites and that of the dumpsites. This result indicates that e-waste contributes to the concentration of heavy metals in the soil and dust sample where e-waste are being dismantled and the dumpsites where the unused electrical and electronic equipment are being disposed.