DES MOINES – The U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration are designating May 2 through May 6 as Air Quality Awareness Week.
The Department of Natural Resources and Linn and Polk counties monitor current air quality in Iowa. Monitoring data are displayed at www.iowacleanair.com.
The EPA has established a color-coded Air Quality Index describing how clean or polluted the outdoor air is in a specific location and associated health effects may result for the local population. The index is color-coded as follows:
Green means the air quality is good and poses no risk.
Yellow stands for moderate air quality. This is acceptable air quality, except it many affect people who are unusually sensitive to air pollution.
Orange means the air is unhealthy for sensitive* groups, but the general public is not likely to be affected. When the air quality enters the orange range it is exceeding the National Ambient Air Quality Standards.**
Red is the level when everyone may experience health effects and sensitive groups may have more serious health effects.
Purple means everyone may experience more serious health effects.
Maroon expresses emergency conditions.
Iowa’s air generally measures within the green to yellow range.
April is the beginning of Iowa’s ozone season, which lasts through October 31. Ozone concentrations can reach unhealthy levels when the weather is hot and sunny with relatively light winds. Ozone is formed by a chemical reaction between volatile organic compounds and oxides of nitrogen in the presence of heat and sunlight. That is why ozone is a concern in the warm months. Sources of those substances include:
automobiles, trucks and buses;
large industry and fuel combustion sources such as utilities;
small industry such as gas stations and print shops;
consumer products such as oil-based paints and cleaning materials; and
emissions from aircraft, locomotives, and construction equipment.
In 2010, Iowa air quality monitors recorded exceedances of the ozone health standard at Pisgah on May 29. Pisgah monitors measure air quality downwind from the Omaha-Council Bluffs metropolitan area. Iowa continues to meet the ozone standard across the state.
*Sensitive groups are children, elderly, those with comprised heart and lung conditions, and outdoor athletes and workers that heavily exert their lungs.
**National Ambient Air Quality Standards are the EPA’s human health-based criteria that determine the limits on the amount of the seven most common pollutants in the ambient air. The criteria pollutants are ground-level ozone, fine and coarse particles, lead, carbon monoxide, sulfur dioxide and nitrogen dioxides. |
