Ecological risk assessment of heavy metals in soils from an informal e-waste dismantling site, Buriram province, Thailand

The research aimed to investigate the contamination and fractionations, and evaluate the ecological risk posed by heavy metals in the e-waste site in Daeng Yai and Ban Pao e-waste dismantling sites, Buriram Province, Thailand. The soil samples were taken from e-waste houses (EW), and e-waste open-burning sites (OB) as representatives of the e-waste sites, while soils from paddy fields (PF), non-e-waste houses, and groundwater wells represented the surrounding area, and the reference site was located 5 km away from the e-waste dismantling site. The soil samples were digested by aqua regia by the microwave digester for total heavy metal determination, and the metals in soils were sequentially extracted following the modified BCR sequential extraction procedure. The contents of As, Cd, Cr, Cu, Mn, Ni, Pb, and Zn were analyzed by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES). The concentrations of Cd, Cu, Pb, and Zn in OB were significantly higher (p