Risk Assessment and Source Appointment of Heavy Metal and Metalloid Pollution in Soil from a Typical Ion-Adsorption Rare Earth Tailing Abandoned for 15 Years

Ion-adsorption rare earth mining activities are accompanied by soil heavy metal and metalloid pollution. The study aimed to determine pollution features, environmental risks, health risks and possible sources of heavy metal and metalloids in typical ion-adsorption rare earth tailing (abandoned for fifteen years). The average concentrations of Mn, Zn, As, Tl, Pb and Cr in the soil reached 290.00, 113.86, 36.16, 3.37, 185.66 and 4.78 mg kg –1 , respectively. The spatial distribution proclaimed that the most severe soil heavy metal and metalloid pollution was concentrated in the northeast, southwest and north of the tailing. The pollution and ecological risk assessment suggested that Pb, Tl, As and Mn were the primary pollutants. The health risk assessment confirmed Tl as a major contributor to non-carcinogenic risk, especially children who faced significant non-carcinogenic risk (hazard index up to 2.2). The positive matrix factorization results revealed that soil parent material source (released by ion-adsorption rare earth mining activities, 32.3%), ion-adsorption rare earth production (25.7%), soil remediation activities (24.4%) and traffic emissions (17.6%) might be the primary potential source of heavy metal and metalloid. This work will offer valuable assistance in the remediation of soil heavy metal and metalloid pollution in the rare earth mining area.