Spatial Distribution, Health Risk Assessment and Source Apportionment of Potentially Toxic Elements in Soils Near...

In China, rare earth mining (REEs mining) is amongst the most important anthropogenic sources of potentially toxic elements (PTEs) release into the soil. In the last few decades, many researchers have conducted studies on PTE pollution in REEs mining areas. Yet, most of those studies only focused on a small geographical area or a single REEs mining, which does not reflect the overall scenario on a national scale. The current study collected data on the concentration of 8 PTEs (Pb, Cd, Cr, Cu, Hg, As, Zn, and Ni) from various research articles published from 2008 to 2024 in six rare earth mining provinces of China, investigated the spatial distribution of PTEs, their contamination level, potential sources and human health risk associated with them. The findings revealed that the average concentration of all eight PTEs was significantly higher than both Chinese and world background values, with Pb, Cd, and Hg exceeding the GB 15618-2018 guidelines for agricultural soils also. The Nemerow composite pollution index (NCPI) results indicated substantially elevated levels of pollution in all REEs mining provinces, with Sichuan having the highest NCPI (50.8). The principal component analysis (PCA) results showed mixed anthropogenic and geogenic sources of pollution for the selected PTEs. The human health risk assessment indicated that children were more at risk than adults via exposure pathways (oral, dermal, inhalation). The carcinogenic risk assessment revealed that Cr posed a significant cancer risk in both children (CR = 4.9 × 10^-3) and adults (CR = 2.1 × 10^-3) while Cu showed no carcinogenic risk in adults (CR = 8.6 × 10^-4) but presented a carcinogenic risk in children (CR = 2.0 × 10^-3), suggesting that children are more prone to the adverse effects of PTEs in REEs mining soils. Therefore, the present study indicates that REEs mining releases PTEs into nearby soils and poses a potential health risk to the surrounding environment, and should be mitigated by the government through effective management strategies.