Heavy Metal Assessment of Ground, Surface and Tap Water Samples in Lagos Metropolis Using Anodic Stripping Voltammetry

The levels of heavy metal contamination in surface, ground and tap waters collected in some part of Lagos metropolis were determined using Differential Pulse Anodic Stripping Voltammetry (DPASV). The samples were analysed for their contents of lead, copper and cadmium and were also compared with the WHO (2008) specified contaminant levels for drinking water. The results obtained showed that all the well water and borehole water samples investigated contain high concentration of these heavy metals. Lead and cadmium concentrations were found to be above the WHO maximum acceptable concentration (MAC). However, none of the samples had copper concentration above the WHO MAC for copper. On the whole samples analysed, only the sample collected from Odo-Iyaalaro stream, Ojota showed no pollution of lead. Other samples showed pollution of all of the metals analysed. In general, the results show an indication of pollution hazards given the toxicity of these metals and mostly when the water sources studied represent the major sources of water for the teeming populace. DPASV results of the samples investigated were found to be comparable with results of same samples obtained from independent work carried out by Atomic Absorption Spectroscopy.