Evaluation of the Effects of Electronic Waste on Topsoil and Groundwater

Abstract

Electronic waste is waste from obsolete electronic equipment such as computers, printers, photocopying machines, Television sets, Mobile phones etc. which are composed of sophisticated blends of plastics, metals, and other materials. These electronic devices are known to contain small amounts of toxic chemicals that when improperly disposed off, infiltrate into the soil, thereby contaminating the groundwater and this can exert, negative effects on human health and the environment. In this study soil and well water were collected from and around a dumpsite in Alaba electronics market Lagos Nigeria. The samples were analysed for the concentration of heavy metals and other physical parameters using Atomic Absorption Spectroscopy (AAS) and other equipment. The result of the analysis of the water samples revealed a slightly alkaline pH of 8.59, electrical conductivity of 3380.3μS/cm, with the heavy metal content ranging from 0.002 to 0.005mg/l for Cadmium, 0.001 to 0.008mg/l for chromium, 0.001 to 0.011mg/l for Nickel, 0.007 to 0.020mg/l for Lead, and 0.003 to 0.007mg/l for Zinc. The heavy metal concentration of the soil samples ranged from 0.5 to 12mg/kg for cadmium, 26 to 45mg/kg for chromium, 110 to 430mg/kg for Lead, 9 to 33mg/kg for nickel and 82 to 890mg/kg for Zinc. The major findings of this research work are the high levels of heavy metals in the topsoil and groundwater samples tested and the attendant health implications as some of the samples exceed the WHO/NIS Standards for water quality and FAO soil quality standards which are (Cadmium 0.005mg/l, Chromium 0.05mg/l, Nickel 0.02mg/l, Lead 0.01mg/l, Zinc 3mg/l) and (Cadmium <1mg/kg, Chromium <50mg/kg, Lead <70mg/kg, Nickel <50mg/kg, Zinc <125mg/kg) respectively. The results highlight the harmful effects of electronic waste and why it should be properly managed either through appropriate landfilling methods or recycling and it also demonstrates the urgent need for action to address the management of hazardous e-waste, and for tighter controls on the trans-boundary movement (importation) of such wastes.