A review of soil potentially toxic element contamination in typical karst regions in southwest China

Soil contamination with potentially toxic elements (PTEs) has been a matter of great concern across China, but the karst regions of southwest China, with one of the three largest karst areas worldwide and a wide distribution of carbonate rocks, have been largely neglected. Here, we review (i) the occurrence and geographic distribution of PTEs in karst soils (ii) the major anthropogenic sources of PTE enrichment in karst soils, especially mining activities and atmospheric deposition, and (iii) the high natural background levels of PTEs developed from the weathering and pedogenesis of parent carbonate rocks in karst regions of southwest China. Future research priorities are suggested for the protection of environmental sustainability, agricultural production, and human health. (C) 2021 Elsevier B.V. All rights reserved.