Stagnant Air and Fog Continue to Cause Elevated Air Pollution Levels Across Iowa

Pollutant levels exceeding U.S. Environmental Protection Agency (EPA) health standards for fine particles were present over most of Eastern Iowa Wednesday, and are predicted to approach or exceed EPA health standards over most of Iowa today. At this level the air can be unhealthy for sensitive groups.

The Department of Natural Resources recommends that Iowans with respiratory or heart disease, the elderly, and children limit prolonged exertion until air quality conditions improve.

The EPA’s 24-hour health standard for fine particles is 35 micrograms per cubic meter. On Wednesday, fine particle levels in Clinton averaged 62 micrograms per cubic meter and 59 micrograms per cubic meter in Davenport. At mid day today, all monitors across the central and northern part of the state averaged more than 35 micrograms per cubic meter; air monitors in Davenport averaged 56 micrograms per cubic meter; and in Des Moines 42 micrograms per cubic meter.

Fine particle levels are expected to remain elevated across Iowa through the end of the day on Friday.

Fine particles are emitted by vehicle traffic and other combustion sources and are also formed by chemical reactions in the atmosphere. Stagnant air masses do not allow the fine particles to disperse, and pollutant levels rise. In the winter, fog droplets at near freezing temperatures capture ammonia and nitric acid and give rise to fine particles made of ammonium nitrate.

EPA’s national air quality map is available online at www.airnow.gov.

For more information contact Sean Fitzsimmons, Ambient Air Monitoring, (515) 281-8923 or Mindy Kralicek, Air Quality Information Specialist, (515) 281-7832.