In this study, the concentrations of V, Cr, Co, Ni, Cu, Zn, As, Cd and Pb in 104 street dusts from Nanchang city in winter and summer were determined. Geoaccumulation index (Igeo), health risk model recommended by USEPA, and multivariate statistical methods (principal component analysis and correlation analysis) were applied to evaluate the pollution degree, calculate the noncarcinogenic risk (HI) and carcinogenic risk (CR) (for children and adult), and identify the possible source of heavy metal, respectively. The result showed that the concentrations of Cr, Ni, Cu, Zn, Cd and Pb in street dust of Nanchang were significantly higher than soil background values of Jiangxi Province, while concentrations of V, Co, and As were comparable to corresponding background values. Concentrations of V, Co, and As had not significant seasonal difference, but had high spatial heterogeneity. Cu concentration had significant difference both in seasonal and spatial distribution. The high level area of the other investigated metals mainly distributed in central Nanchang and old industrial area. The result from Igeo indicated that Cd, Cu, Zn, and Cr had higher pollution degree, while V, As, and Co had lower degree. The health risk from three exposures sequenced as handmouth ingestion>dermal contact> inhalation, and the child suffered the higher risk than the adult. The HQ and HI of all investigated metals were below one, except the HQ and HI of As and Cr exceed one in some sites. The Carcinogenic risk from metals in street dust were limited within the safe threshold range, and the sequence followed Cr > As > Co > Ni > Cd. There were various sources of metals in street dust from the Nanchang city, As, Co and V were mainly derived from rocks weathering, while the other metals came from the anthropogenic activities including the traffic and industry.

Key words：street dust; heavy metal; spatialtemporal distribution; health risk; Nanchang city