TUESDAY, June 21 (HealthDay News) -- A strong association exists between long-term exposure to air pollution and uncontrolled asthma, new research indicates.

The study included 481 adults with asthma who provided details about their respiratory health between 2003 and 2007. The researchers compared this information with levels of three types of air pollution -- ozone (O3), nitrous oxide (NO2) and particulate matter (PM10) -- in the five cities in France where the participants lived.

About 44 percent of the participants had well-controlled asthma, 29 percent had partially controlled asthma and 27 percent had uncontrolled asthma. Women and older people were more likely to have uncontrolled asthma.

There was a strong association between poorer asthma control and levels of ozone and particulate matter. The risk of uncontrolled asthma was 69 percent higher among those with long-term exposure to ozone and 35 percent higher for those with long-term exposure to particulate matter.

The study appears online June 21 in the Journal of Epidemiology and Community Health.

"Our results indicate that both ambient O3 and PM10 concentrations jeopardize asthma control in adults," the researchers concluded in a journal news release. "Our results are robust."

More information

The U.S. National Heart, Lung, and Blood Institute has more about asthma.