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Ground-level Ozone Pollution

Health Effects of Ozone Pollution

diagram of human lungsOzone is a powerful oxidant that can irritate the airways.

Ozone in the air we breathe can harm our health, especially on hot sunny days when ozone can reach unhealthy levels. Even relatively low levels of ozone can cause health effects.

Who is at risk?

People most at risk from breathing air containing ozone include people with asthma, children, older adults, and people who are active outdoors, especially outdoor workers. In addition, people with certain genetic characteristics, and people with reduced intake of certain nutrients, such as vitamins C and E, are at greater risk from ozone exposure. 

Children are at greatest risk from exposure to ozone because their lungs are still developing and they are more likely to be active outdoors when ozone levels are high, which increases their exposure.  Children are also more likely than adults to have asthma.

What health problems can ozone cause?

diagram of constricted alveoliOzone can cause the muscles in the airways to constrict, trapping air in the alveoli. This leads to wheezing and shortness of breath.

Depending on the level of exposure, ozone can:

  • Make it more difficult to breathe deeply and vigorously.
  • Cause shortness of breath, and pain when taking a deep breath.
  • Cause coughing and sore or scratchy throat.
  • Inflame and damage the airways.
  • Aggravate lung diseases such as asthma, emphysema, and chronic bronchitis.
  • Increase the frequency of asthma attacks.
  • Make the lungs more susceptible to infection.

These effects have been found even in healthy people, but can be more serious in people with lung diseases such as asthma. They may lead to increased school absences, medication use, visits to doctors and emergency rooms, and hospital admissions. 

Long-term exposure to ozone is linked to aggravation of asthma, and is likely to be one of many causes of asthma development. Studies in locations with elevated concentrations also report associations of ozone with deaths from respiratory causes.

How can I reduce these health risks?

diagram of airway inflammationWith inflammation, the airway lining is damaged. It has been compared to the skin inflammation caused by sunburn.

The AirNow Web site provides daily air quality reports for many areas. These reports use the Air Quality Index (or AQI) to tell you how clean or polluted the air is.

EnviroFlash, a free service, can alert you via email when your local air quality is a concern. Sign up at www.enviroflash.info.

Pamphlets and other resources: