Abstract: The aim of this work was to study the distribution characteristics of heavy metals in street dust during heating period and unheating period, and their health risk to human due to dust exposure in Shenyang. The mean Zn, Cu, Pb and Cd contents in street dust were 13.23, 2.87, 3.68, and 7.35 times as high, respectively, as the background values in soil during heating period, and these values were 4.52, 3.12, 3.33, and 6.64 times high during unheating period. In heating period, the contents of Zn and Pb were in order of residential area > industrial area > commercial area, the Cu content was in order of industrial area > commercial area > residential area, and the Cd content was in order of industrial area > residential area > commercial area. In unheating period, the contents of heavy metals in street dust in residential area were lower than those in industrial area and commercial area, except Pb. The sequence of noncarcinogenic risk (HI) was Pb>Zn>Cu>Cd in heating period, while it was Pb>Cu>Cd>Zn in unheating period. Almost HI values in this study were lower than 1, indicating that the risks of these metals to human health were low or could be ignored.

Key words: safe growth period, breed collocation, climate change, thermal resources, double cropping rice, thermal growth period