Heavy metals in soils around non-ferrous smelteries in China: Status, health risks and control measures

Non-ferrous smelting is a primary cause of serious soil pollution. Contamination and health risks of heavy metals in soils around various types of non-ferrous smelteries in China were assessed using data from peer-reviewed papers published between 2000 and 2019. Development in the relevant environmental policy in China was discussed. The studied non-ferrous smelting sites were mainly located in provinces that produced non-ferrous metals on a large scale. The average concentrations of the heavy metals in soils around the non-ferrous smelteries (in mg per kg of soil) were as follows: Cd, 19.8; Cu, 265; Pb, 1536; and Zn, 1371; the concentrations greatly exceeded their corresponding background values. The smelting sites with high soil contamination in terms of metal concentrations, geo-accumulation (I_geo), and pollution index (PI) were mainly distributed in several provinces of China, including Guangxi, Gansu, Hunan, Hubei, Chongqing, and Liaoning. Soils near smelteries that processed copper were the most polluted based on I_geo and PI. The accumulation of Cd and Pb in soils around non-ferrous smelteries would pose potentially high risks to residents. A series of environmental policies have proven successful in lowering the emissions of contaminants from the non-ferrous in China. The findings of the study suggested that the strategies to control soil pollution around non-ferrous smelteries should primarily focus on Cd and Pb.