| Abstract: | On 20 March, 2002, a super dust storm attacked Beijing, which was stronger than any dust storm ever recorded. The concentration
of total suspended particulates (TSP) reached 10.9 mg · m?3, 54 times as high as the national air quality standard. The concentrations of major crustal elements, such as Ca, Al, Fe,
Na, Mg and Ti, were 30–58 times higher than those in non-dust storm days. The concentrations of pollution elements, such as
Zn, Cu, Pb, As, Cd and S, were also about several or even nearly ten times higher than those in normal days. The enrichment
factors of Pb, As, Cd and S in PM2.5 were as high as 12.7, 29.6, 43.5, 28.4, indicating that these pollutants came from the
mixing of mineral aerosol with pollution aerosol emitted by pollution sources on the way of dust storm’s long-range transport.
The overlap of invaded air mass from dust with pollution air mass from Beijing local area was another reason for the enhancement
of pollutants. During dust storm, fine particles (PM2.5) accounted for 30% of TSP and pollutants in PM2.5 accounted for even
as high as 45%–69% of TSP. The increase of pollutants after dust storm proved further that mineral aerosol, especially the
fine particles from dust storm favored the transformation and accumulation of pollutants. It must be noted that Fe (II) was
detected again in this dust storm, which provided new evidence for the mechanism of coupling and feedback between iron and
sulfur in the atmosphere and the ocean. The increase of both pollutants and nutrient, Fe(II), during dust storm illuminated
that dust storm is an important factor affecting the global environment change. |
