Protect Your Lungs During Ozone Season


We know about spring, summer, fall, and winter, but did you also know that there was an “ozone” season? UNC Medical Center health and air-pollution expert David Peden MD gives advice for staying healthy during the months of higher ozone pollution.

April marks the beginning of the ozone season, which actually peaks in the warmer summer months. The length of the ozone season varies from one area of the US to another. Those in the warmer climates, such as the Southern and Southwestern states tend to have longer seasons.

Ozone, a pale blue gas, is a protective component of the upper atmosphere, where it protects the earth from much of the sun’s harmful rays. But through car exhaust, power plants, gas stations, and industrial facility emissions, the ozone content of the lower parts of the atmosphere reaches an unhealthy range, affecting the health of many, particularly those with respiratory disease or who work outdoors.

Exposure to ozone inflames the lungs, which can aggravate other breathing problems such as asthma or seasonal allergies, says Dr. Peden, director of the Center for Environmental Medicine, Asthma and Lung Biology at the UNC School of Medicine. Long-term chronic exposure can affect lung development in children. Peden is also researching a link between ozone and cardiovascular disease.


To protect yourself, learn the day’s ozone level through your favorite weather forecaster. Code Orange means that the air is unhealthy for sensitive people. Code Red indicates that everyone should avoid breathing outdoor air. On ozone-elevated days, avoid outdoor air particularly in the afternoon when ozone levels peak.

“Do most of your vigorous outdoor work in the morning or in the evening, after the ozone has decreased,” he said. Physical activity causes people to breathe faster and more deeply, thus taking in more ozone with their oxygen.

Diet may help to reduce the effects of ozone exposure. Peden says that some studies suggest that eating foods rich in antioxidants, such as colorful fruits and vegetables, can help.

As today is Earth Day, also take into consideration the steps that you can personally take to help reduce the air pollution and ozone levels. offers these tips:

• Choose a cleaner commute -- share a ride to work or use public transportation.
• Combine errands and reduce trips. Walk to errands when possible.
• Avoid excessive idling of your automobile. Also remember to keep your tires properly inflated.
• Refuel your car in the evening when it's cooler. Take care not to spill fuel, and always tighten the gas cap securely.
• Conserve energy at work, home, and everywhere you spend time. Set air conditioners no lower than 78 degrees, turn off lights, and unplug electrical items that are not being used.
• Consider ENERGY STAR products when purchasing new. These are environmentally friendly products approved by EPA.
• Use household, workshop and garden chemicals in ways that minimize evaporation, or try to delay using them when ozone levels are high.
• Defer lawn and gardening chores that use gasoline-powered equipment, or wait until evening.
• But of course, plant a tree! It can not only provide shade in the summer, reducing the need for air conditioning, but plants help make for better air quality by releasing oxygen.
• Reduce, reuse, recycle. Doing this can help prevent excess processing from those industrial plants that are contributing to poor air quality. It can also help save those trees that we already have.