The Iowa Department of Natural Resources released this today:
(Feb. 25, 2013) – Elevated fine particle pollution levels were recorded across eastern Iowa this morning. Fine particle levels above EPA health standards are likely to persist in Black Hawk and Linn Counties until early Tuesday morning, when northeast winds are expected to clear the air.
The Iowa DNR recommends that Iowans living in Black Hawk and Linn Counties with respiratory or heart disease, as well as elderly and children limit prolonged outdoor exertion in the area until air quality conditions improve.
The EPA’s 24-hour health threshold for fine particles is 35 micrograms per cubic meter. As of noon today, the average fine particle levels were 41.2 in Cedar Rapids and 47.3 in Waterloo. Several other monitors in the state recorded elevated levels. Fine particle levels were 29.6 in Clinton, 37.8 in Davenport, 31.6 in Des Moines, 33.5 in Emmetsburg, 36.4 in Iowa City, 25.5 in Lake Sugema State Park and 32.9 in Muscatine.
On Sunday, an air monitor in Waterloo recorded a 24-hour fine particle level of 36.7.
Fine particles are emitted by vehicle traffic and other combustion sources, and are formed by chemical reactions in the atmosphere. Stagnant air masses do not allow fine particles to disperse and pollutant levels rise.
EPA’s national air quality map is available online at www.airnow.gov.