Ecological and Health Risk Assessment of Metal in Resuspended Particles of Urban Street Dust from an Industrial City in China

Concentrations and ecological and health risks of metals in the resuspended particles of urban street dust collected from an industrial city, Baotou, China were studied. The results show that the average concentrations of Ba, Co, Cr, Cu, Mn, Ni, Pb, V and Zn in the studied samples are 990.1, 56.2, 247.8, 31.5, 566.3, 26.1, 59.9, 82.2 and 77.5 mg kg^-1 respectively, which are higher than the background values of Inner Mongolia soil, especially Co, Cr and Pb. The results of potential ecological risk analysis demonstrate that Ba, Mn, V, Zn and Ni in the samples are in low ecological risk levels whereas Cr, Cu and Pb are in low to moderate ecological risk levels. Co reveals moderate to considerable ecological risk. The aggregate ecological risk of metals in the resuspended particles of street dust from Baotou is in the moderate level. Human health risk assessment shows that ingestion is the main exposure pathway of metals in dust to the local habitants. The upper limit of the 95% confidence interval of hazard indices for non-cancer risks of all analysed metals in the resuspended particles of street dust is within the safe level, while the maximum hazard index of Cr for children exceeds the safe level. Thus, the health risk of Cr for children due to dust exposure is a matter of concern. The cancer risk of Co, Cr and Ni to local habitants, considering only inhalation, is within the currently acceptable range.