Assessment of Heavy Metal Contamination on Soil around E-Waste Dumpsite in Onitsha, Nigeria

Abstract

Electronic waste (e-waste) has become an issue of major importance as production technology rapidly develops and changes, and more unknown components of the waste enter the municipal waste stream. The absence of a structured management system and laxity in environmental laws and regulations in Anambra State have led to an increased influx of e-waste into the state. It has created an avenue for uncontrolled and crude methods of recovering valuable metals from waste. These e-wastes are dismantled, some are burnt without prior knowledge of their composition and noxious matters are released into the environment. This study aimed to establish an understanding of the extent of heavy metals contamination on the soil around e-waste dumpsite in Ochanja in Onitsha, Anambra State with a view to generating baseline data on the extent of contamination of heavy metals from e-waste. Experimental research design was adopted and primary data were obtained through the collection of four different soil samples at varying distances within Ochanja e-waste dumpsite , the study Area. The collected soil samples were analyzed using Atomic Absorption SpectrophotometerAAS(GBC932AA) for the following heavy metals; Lead(Pb), Cadmium(Cd) Hexavalent chromium(Cr),Copper(Cu), Aluminium(Al) and Nickel(Ni). The result of the analysis showed that Al and Cr had maximium average value of 393.65mg/kg and 161.70mg/kg,followed by Pb(111.4mg/kg),Cu(102.37mg/kg),Cd(11.79mg/kg) and Ni(6.43mg/kg).The heavy metal concentrations in the soil were generally above 100mg/kg with exception of Cadmium (11.79mg/kg) and Nickel(6.43mg/kg),while the average concentrations of Al,Cu and Cd are above USEPA standard of 300mg/kg,50mg/kg and 3mg/kg respectively. The significant heavy metals found in soil samples in and around the dumpsites in the study area likely resulted from poor management of e-waste in the dumpsite in the study area. This is an indicator that the negative health impact of these heavy metals should be further investigated to avert any health and environmental consequences in the study area.

Keywords: E-waste, Heavy Metals, Soil, Contamination, Environment, Dumpsite.