Spatial and ecological health impacts of potentially toxic elements in road dust from long-term mining activities: A case study of the Bayan Obo deposit

The long-term impacts of mining activities at the Bayan Obo deposit on potentially toxic elements (PTEs) in road dust remain insufficiently understood. This study aims to enrich knowledge in this area by investigating the spatial and eco-health impacts of PTEs in both bulk road dust (BRD) and resuspended road dust (RRD) from mining. An integrated approach combining Monte Carlo simulations with multiple statistical and geostatistical methods was used to quantify mining-related impacts. The findings revealed that Cd was the most polluted element. Concentrations of Cd, Mo, Pb and Zn were notably higher near the mine and decreased with increasing distance, with mining activities directly contributing over 20 % to these PTEs. Moderate and considerable eco-risks were identified for BRD and RRD, respectively, primarily driven by Cd and Mo, with higher risks closer to the mine. While non-carcinogenic risks were negligible, carcinogenic risks for adults required attention. Mining-related sources accounted for over 30 % of eco-risks but less than 10 % of health risks. This research integrates multiple methods, providing a more comprehensive understanding of the spatial and eco-health impacts of mining activities on PTEs in road dust. These findings offer critical insights and guidance for managing similar environmental challenges in other mining regions.