Abstract: The concentration of the main elements of the alkaline dust storm from Western Songnen Plain follows the decreasing order of Na, Al, Fe, Ca, Mg, K, Ti, Ba and Zn, which is compatible with the element composition of local saline soil but quite different from the normal sand dust and municipal aerosols. The relationship between wind and aerosol composition suggests that at the critical wind speed of alkaline dust storm (ADS) of 8.0~17.1 m/s,the concentration of the main elements follows the decreasing order of Na,Ca,Al,Fe,Mg,K,Ba,Ti and Zn.Enrichment factor (EF) values of element Na increase sharply during ADS, in contrast to the decrease of Zn, B, Cu etc., which indicates that EF values of most hazardous metals are smaller during ADS periods than no ADS periods. The lower EF values of these hazardous metals during ADS periods can be ascribed to the excessive input of saline components, such as Na, Ca. EF value of Ca, Fe, K, Mg, Mn, Sr, V is around 1~4. As EF values of major elements are almost the same between two sampling sites, while the trace elements, such as B, Ba, Cu and V can be used to distinguish the dust sources because of the considerable differences between the two sampling sites.

Key words: Songnen Plain, alkaline dusts, aerosol, element compositions, enrichment factor