For kids and adults with asthma, the start of summer means a new season of worrying about what’s in the air.

City dwellers with asthma face the threat of ozone air pollution when it gets very hot outside. Ozone is caused when strong sunlight and still air mix with vapors from cars, gas pumps, gas-powered lawn mowers, refineries and other pollutants. It’s different from the kind of ozone that protects Earth from the sun’s rays.

Air Quality Index

You might hear the terms “ozone action day” or “air quality alert” in the news during the summer. This lets the public know weather conditions are ripe for ozone to develop. If you have breathing problems, it’s a good habit to check the Air Quality Index (AQI) every day at


The AQI uses colors, from green to dark red, to show the quality of the air. As it gets closer to red, kids and adults with asthma are at risk for bad attacks.

That, in turn, can lead to more trips to the ER. In a study of young campers, 40 percent were more likely to have acute asthma attacks on high pollution summer days than on days with average pollution, according to the Asthma and Allergy Foundation of America.

On the days when the AQI is orange or higher, people with asthma should limit outdoor exercise or strenuous activities. In severe asthma cases, consider reducing heavy outdoor activity when the AQI is yellow. If the AQI gets to red or purple, everyone with asthma should avoid all outdoor activities. And no matter what the AQI is, people with asthma should always avoid exercising near high-traffic areas so they can steer clear of pollution.

Smog and Air Pollutants

Ozone can be part of the smog that’s sometimes visible in the air. Smog is very unhealthy because it contains tiny particles, the same kind that block the sun when smog is thick, says Marcy Ballman, PhD, a health services manager for the American Lung Association.

“Those particulates are so small that when you breathe in, they can make it to the lowest reaches of your lungs,” Ballman says. “A healthy person is fine when they breathe those in. But when people with asthma are exposed to the same thing, they have a more extreme reaction. It’s not a different exposure, but their lungs are more sensitive.”

While rural areas typically don’t have industrial pollution, asthma sufferers there can still be affected by air quality problems in the summer. They often have flare-ups because of smoke from campfires and wildfires, exhaust from heavy farm equipment, and irritating chemicals.

Pollution can build up quickly in some areas because hills or mountains trap it in a small space. For example, Ballman experiences air quality alerts in her town of Missoula, Montana, because particulates that come from burning wood can become trapped in the mountain valley. Being outdoors in the summer can also trigger outdoor allergies, which may lead to an asthma attack.

If you’re going camping this summer, don’t despair. This doesn’t mean you or your kids have to skip making s’mores by the fire. “Just stay out of the smoke,” Ballman says. “You should be fine, as long as you aren’t standing straight in the smoke.”

If your child has been playing outside, be sure he or she changes clothes to avoid bringing outdoor allergens into the home, then wash those clothes in hot water.

For more information about managing asthma symptoms, please visit our Taking on Asthma website.


Stay informed.

In addition to checking, you can sign up for email alerts to get up-to-date AQI information. You can also download free mobile apps. The Environmental Protection Agency offers the AIRNow app at the App Store and Google Play. Get the American Lung Association’s State of the Air app from the App Store or Google Play.