Pollution characteristics, sources and health risk of potentially toxic elements in urban road dust from different functional areas in Hefei, China.

The rapid urban expansion of Hefei has led to the accumulation of potentially toxic elements (PTEs) in urban road dust (URD), posing threats to ecological environmental safety and public health. This study collected road dust samples from five functional zones in Hefei City to assess the contamination levels, ecological and health risks, and source apportionment of 11 PTEs, As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Ti, V, and Zn. Results revealed that the average concentrations of As, Cd, Cr, Cu, Pb, and Zn exceeded local background values, with contamination levels in the order Zn > Pb > Cu > Cr > As > Cd. Spatially, industrial areas and leisure areas exhibit higher pollution levels compared to other areas. Assessments using the geo-accumulation index (Igeo) and enrichment factor (EF) consistently identified Zn, Cd, Cu, and Pb as the primary pollutants. The potential ecological risk index (RI) further revealed that Cd was the primary contributor to ecological risk. Integrated analysis using principal component analysis (PCA) and positive matrix factorization (PMF) models identified three primary pollution sources: industrial emissions source (31.97%), natural sources (18.80%), and a mixed traffic-natural source (49.23%). Regarding health risks, although the risk for adults remained within an acceptable range, children showed greater susceptibility. This study provides insights for implementing zonal and categorical pollution control and risk prevention in Hefei City. It also offers a case reference and scientific basis for PTE pollution prevention strategies in other rapidly developing cities.