Geochemical distribution and environmental risk assessment of trace metals in groundwater released from e-waste management activities in Lahore, Pakistan.

Abstract

Non-sustainable e-waste recycling and dumping activities release trace metals into the ambient environment where they may threaten the biological communities and human health. A total of 45 groundwater and 21 leachate samples were collected from seven recycling, seven dumping, and one reference site in Lahore, Pakistan, and analyzed for Cu, Pb, Zn, Cd, Mn, and Fe in atomic absorption spectrophotometer. Comparing the results with the World Health Organization (WHO) standards of drinking water, only the concentrations of Cu, Zn, Mn, and Fe at all sites were found to be within the permissible limits, i.e., 2, 3, 0.5, and 1mg/L, respectively. In leachates, only Cd and Mn at one site (0.204 and 8.636mg/L, respectively) exceeded the allowable limits of National Environmental Quality Standards of Municipal and Liquid industrial effluents. Geo-accumulation index, contamination factor, contamination degree, and pollution load index values showed no to moderate contamination. The ecological risk index did not exceed 150, depicting low risk to nearby biological communities. The non-carcinogenic health risk assessment showed a hazard index value greater than 1 at all sites for children (2.04) and adults (1.52), with Pb being the major contributor to adverse health impacts via ingestion and dermal route. Children (1.21 × 10-4) were at a more significant threat of carcinogenic risk from Pb and Cd as compared to adults (8.10 × 10-5). Therefore, there is a dire need to introduce sustainable e-waste recycling and managing techniques to reduce further groundwater contamination via the percolation of trace metals and to reduce the current contamination level.