Concentrations, spatial distribution, sources and environmental health risks of potentially toxic elements in urban road dust across China

Potentially toxic element (PTE) pollution is widespread in road dust across China, and the effects of PTEs in road dust on health cannot be ignored. In this study, the concentrations of six PTEs (Pb, Cd, Cr, Cu, Zn and Ni) in 4336 road dust samples from 58 cities in 31 provincial regions of China taken after 2000 were obtained from the literatures. Based on these data, the spatial distribution, pollution sources, and ecological and human health risks of PTEs in road dust were comprehensively assessed and the main pollution factors and areas of high risk were identified. The results revealed that PTE levels are generally higher in eastern cities than western cities in China. The key driving factors are socioeconomic factors, including those related to transportation, industry, and population, for which the contribution rates are 57.80%, 55.39% and 37.19%, respectively. PTEs in the road dust with high ecological risks are mainly distributed in the southeastern coastal areas and the Beijing-Tianjin-Hebei region. No obvious noncarcinogenic risk was found for PTEs in road dust, but Cd and Pb may have potential noncarcinogenic risk, mainly distributed in cities in western China. Therefore, regions and pollution sources contributing to Pb and Cd levels should be monitored. The control of PTE pollution in China is a priority for ecological and environmental protection. (c) 2021 Elsevier B.V. All rights reserved.