It's a stride toward public awareness, an effort to decrease pollution and related health risks.

It could change parents' decisions to have children play inside or for others to ride bikes to work instead of driving cars.

A University of Iowa group of 12 people, including professor Greg Carmichael and a mix of graduate and undergraduate students, is teaming up with NASA and hundreds of other scientists around the world to forecast air pollutants.

The experiment aims to "really understand what pollutants are in the air and how widely spread pollution is," said Carmichael, associate dean for graduate studies and research in the UI College of Engineering.

More than 200 government and university scientists from as far away as Canada and Europe are sampling the quality of air this summer as part of the International Consortium for Atmospheric Research on Transport and Transformation. The experiment, which began July 1 and ends this month, is the largest air quality study to date, experts say.

"Of all of the studies, this one is the largest in terms of the number of scientists involved, the number of measurements put into the field, and really the extent of the kind of study that we're following," said Fred Fehsenfeld, senior scientist with the National Oceanic and Atmospheric Administration, which provides weather services.

The experiment involves 11 aircrafts, two balloons, one ship, satellites and other surface objects that help researchers and scientists understand how air is produced and transported across the United States and overseas, Carmichael said. Other participating countries include Canada, Great Britain, Germany and France.

UI's role is to provide chemical weather forecasts. By using computer-simulated models, researchers can predict the locations of pollutant clouds. Planes then fly into the clouds to measure the air quality.

Research has shown that smoke from recent Alaskan forest fires has blown over Iowa several times, Carmichael said, eventually traveling to Louisiana and Europe. Such smoke can stay intact for more than a week, he said, adding that precipitation, such as rain, eventually dilutes smoke.

State officials say Iowa City, so far this summer, has not had "unhealthy levels" of air pollutants, such as smog or microscopic soot in the air. If the air does reach unhealthy levels, many people including children, elderly, athletes and outdoor workers, are at risk of respiratory symptoms, said Brian Button, air information specialist for the Iowa Department of Natural Resources.

Iowa reaches unhealthy levels a handful of days a year, Button said. In California, air levels are deemed unhealthy at least 60 days a year, he said.

Such levels could cause cardiac health problems and respiratory problems, two major concerns of urban air pollution, said Peter Thorne, UI professor of toxicology and director of the Environmental Health Sciences Research Center.

Pollution can lead to heart attacks and often adds stress to the hearts of people with underlying diseases, Thorne said. Pollution also makes it hard for people to breathe, he said, adding an estimated 15 million people have asthma.

Cost estimates are not yet available for the experiment, Fehsenfeld said, adding several agencies have contributed funds, including NOAA, NASA, the U.S. Department of Energy, the National Science Foundation, Canadian and European agencies.

Researchers plan to meet in spring 2005 to discuss results, he said.