'Safe' Pollution Days Can Trigger Asthma
Low Ozone Levels Trigger Breathing Problems in Some Children With Asthma
Focus on Ozone
Gent's study measured respiratory symptoms, such as wheezing, persistent cough, chest tightness, and shortness of breath in 271 asthmatic children under age 12 during the spring and summer. The asthmatic children taking maintenance medication seemed to react specifically to ozone but not to other sources of pollution.
"What's interesting about our report is we happened to study the children during the summer, when fine particles weren't really a player -- there wasn't a single day when fine particle levels were anywhere near high levels," says Gent, of Yale University's Center for Perinatal, Pediatric, and Environmental Epidemiology. "So this was a chance to specifically look at ozone."
One explanation: Fine particle pollutants result from the burning of coal, wood, and oil, releasing tiny particles invisible to the eye that are usually found in smoke or haze. Since they largely come from heating fuels, fine particles are usually higher in the winter. However, ozone is often worse in the summer because sunlight and hot weather form it and increase its concentration in the air.
However, her study did not examine the specific maintenance medications the children were taking.
The bottom line: "Patients and parents of children with asthma should be aware of the ozone alert forecast, which is widely publicized in news reports," write George D. Thurston, ScD, and David V. Bates, MD, in an accompanying editorial.
"Of the many triggers of asthma in the environment, air pollution is one of the few that can be legislated and regulated. Therefore, policy makers and regulatory agencies governing air quality necessarily have an important responsibility in ensuring that greater efforts are made to clean the air by reducing the emissions that lead to ozone formation, thereby helping to improve the health of adults and children with asthma."