Abstract:

 The samples of atmospheric particulate matter were collected from 11 districts/counties of Beijing, the content distribution characteristics in TSP, PM10 and PM2-5, and geochemical characteristics of Cd in them （TSP, PM10, PM2-5) were analyzed，the ecological risk of Cd in atmospheric particulates was assessed. The results indicated that the mass concentration of PM2-5 exceeded the standard highest among three particle sizes of atmospheric particulates in Beijing. With heavy metals in PM10, most of them are concentrated in PM2-5. Except Miyun and Tongzhou, the concentration level of Cd in three particle sizes of atmospheric particulates is TSP＞PM10＞PM2-5. Comparing with different functional areas, the mass concentration of Cd in the park is higher than that in the education area and farmland area, so the environmental quality problems in the park should arouse the relevant departments  concern. Although the non-cancer risk of Cd of atmospheric particulates is low，the non-cancer risk in Haidian district is the highest in Beijing. Therefore, more attention should be paid to the environmental health issues in Haidian district.

Key words: atmospheric particulate matter, Cd, geochemical characteristics, ecological risk assessment, Beijing