Emily Fischer, a University of Washington doctoral student in atmospheric sciences, said dust from the Gobi and Taklimakan deserts is routinely present in the air over the western United States during spring months.

"We are interested in Asian dust that comes across the Pacific because particles can have an impact on health, as well as on visibility," Fischer said Thursday in a news release.

Fischer found that in years with large Asian dust storms there was an increase in particles of 2.5 microns or less in the air over the western United States. Particles that small can be inhaled more deeply into the lungs and so are a greater health concern.

The research is being presented this week at the annual meeting of the American Geophysical Union in San Francisco.

"The transport of dust across the Pacific is not a new phenomenon," Fischer said. "But we are just beginning to understand it and quantify it on a year-to-year basis instead of on a case-by-case basis.