For Immediate Release July 1, 2002

Air Quality Improves After ozone smog hits East and West Iowa
For more information contact Brian Button 515-281-7832

DES MOINES-Good to moderate air quality returned to Iowa as ozone smog hit extreme sides of the state this week. Harrison county and adjacent areas in extreme western Iowa experienced an Air Quality Index of 104 on Tuesday for ozone smog, a level considered unhealthy for sensitive groups engaged in prolonged outdoor exertion. The Scott and Clinton county area hit 124 on Sunday and 100 on Monday.

"We should see the AQI in the 40s to low 50s across the state today, levels in the green, or good category," said Brian Button, DNR air information specialist. No health effects are associated with air quality in this range.

Levels 101 and higher are considered unhealthy for sensitive groups such as asthmatics under the national Air Quality Index (AQI), which reports pollution levels using a color-coded and numerical range for pollutants. The higher the AQI, the poorer the air quality.

An AQI of 1 to 50 is green or good, 51 to 100 is yellow or moderate, 101 to 150 is orange or unhealthy for sensitive groups, 151 to 200 is red, unhealthy for everyone. Rarely used in the nation are purple for very unhealthy (201 to 300) and maroon for hazardous (301 to 500.)

Ozone smog forms when emissions from vehicles, utilities and boilers and fumes from paints, gasoline and chemicals "cook" or react in sunlight and warm temperatures to form ground-level ozone, a colorless gas capable of irritating lung tissue.

In Iowa, the overwhelming majority of days fall into the good to moderate categories and all of Iowa currently meets federal outdoor health standards, although extreme eastern Iowa is pushing the standards.

In many U.S. communities, AQI values are mostly below 100, with values greater than 100 occurring several times a year. Several metropolitan areas in the United States have more severe air pollution problems, and the AQI in these areas may often exceed 100. AQI values higher than 200 are very infrequent and AQI values above 300 are extremely rare.

Iowans can check air pollution levels at www.iowacleanair.com.