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FOR IMMEDIATE RELEASE - Sept. 24, 1999
99-189
Contacts: Larry Altose, public information officer, (425) 649-7192
Bill Schillinger, WSU research agronoist, Lind Research Station, (509) 659-0355
OLYMPIA - Yesterday's dust storm in Eastern Washington could be just the beginning of a dusty autumn, according to state air-quality officials.
Dust in the air yesterday triggered high air-pollution levels in Kennewick and moderate levels in Spokane, according to preliminary data collected by state and local air-quality agencies. Dry topsoil on farms contributed most of the dust, especially from fields where practices that could prevent wind erosion have not been used.
More dusty days are possible this fall, according to Grant Pfeifer, Eastern Region air quality program supervisor with the Washington Department of Ecology. "Three things come together this time of year that can cause dusty air in Eastern Washington," he said, "The soil is dry, there tend to be windy days, and many fields are open because they are fallow or newly seeded."
In Kennewick, where the Benton Co. Clean Air Authority operates an air monitoring station, pollution from airborne particles averaged 8 percent above the national standard for healthy air. In Spokane, a monitor operated by the Spokane County Air Pollution Control Authority detected particulate concentrations just 10 percent below the clean-air threshold. Both readings are preliminary and not part of official air-quality records.
Farming techniques that take advantage of crop residue are the key to controlling dust during wind storms in the late summer and early fall, according to Bill Schillinger, a research agronomist with the Washington State University Department of Crop and Soil Sciences, at the Dryland Research Station in Lind, Adams County.
"More than 90 percent of the dryland wheat growers now use reduced tillage or no tillage that keep crop residue on the field surface," Schillinger said. "Fields that have just been seeded after sitting fallow for a year are particularly vulnerable to wind. Excessively tilled farm fields, along with other unprotected ground, such as poorly managed construction sites or dirt roads, offer almost no protection."
Schillinger added that yesterday's storm came at the peak season for dust storms. "For both dryland and irrigated fields, this time between summer tillage and planting the next crop is very sensitive for dust," he said.
More windy days could come before that happens. Schillinger noted that fall and early winter months typically have six or seven days of sustained wind over 15 miles per hour. Winds over 20 miles per hour, like yesterday, come once or twice a month.
Particulate matter in dust storms is very small and can be inhaled deeply into the lungs, where it can damage sensitive tissues. People with respiratory illnesses, the elderly, young children, pregnant women and anyone engaged in strenuous physical activity outdoors are most at risk.
When a dust storm occurs, people can reduce their exposure to particulate matter by:
Fine dust can remain suspended in the air after the wind stops blowing. Air in some low-lying areas can become "stagnant" and particles may settle out of the air slowly. People interested in preparing for dust storms should keep abreast of local weather forecasts.
Additional contacts:
Copyright © Washington State Department of Ecology. See http://www.ecy.wa.gov/copyright.html.
