Contamination and Health Risk Assessment of Exposure to Heavy Metals in Soils from Informal E-Waste Recycling Site in Ghana

The objective of this study is first, to investigate the level of heavy metals in soils from Agbogbloshie e-waste processing site (AEPS), the degree at which these heavy metals contaminate the area and finally, to assess the carcinogenic and non-carcinogenic health risk of heavy metals on workers and residents in around the AEPS. 132 soil samples were collected from the study area and the samples analyzed for Ba, Cd, Co, Cr, Cu, Hg, Ni, Pb and Zn heavy metals after appropriate preparations were made. Results of the analysis showed mean concentrations of Cd, Cr and Ni considered as carcinogenic were lower than permissible levels of Dutch and Canadian soil standards. Mean concentrations however of Cu, Pb and Zn were between 100% and 500% higher than the permissible levels. Assessment of the degree of Contamination indicated Ni<Ba<Co<Cr<Zn<Hg<Cu<Cd<Pb in an increasing order as contributing to the degree of contamination with according to the degree of contamination index the burning, dismantling, residential and commercial considered as very highly contaminated. The health risk analysis of individual heavy metals in soil indicated non-carcinogenic risk of Cr, Hg and Pb with hazard index above the safe level of 1 in the burning and dismantling areas and as such could trigger neurological and developmental disorders in children less than six (6) years

Spatial assessment of soil contamination by heavy metals from informal electronic waste recycling in Agbogbloshie, Ghana

Objectives This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. Methods A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination (Cdeg), we analyzed the individual contribution of each heavy metal contamination and the overall Cdeg. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. Results Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall Cdeg. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. Conclusions Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and Cdeg, indicating soil contamination in AEPS with the nine heavy metals studied