Background Information

Ground-level ozone is a public health concern. It can cause shortness of breath, coughing, wheezing, headaches, nausea, and throat and lung irritation. Young people, the elderly, and those with pre-existing respiratory conditions are the most vulnerable, but even healthy adults can be affected. These health effects can occur at relatively low levels of ozone concentration. Ground-level ozone standards were originally set by the Environmental Protection Agency to protect public health. The Central Texas region has exceeded these health-based standards. Our goal is to improve air quality so that Central Texans can continue to enjoy a clean environment and a healthy quality of life.

Children at Risk

Even healthy children are at risk because they spend much more time outdoors (an average of 50% more than adults), particularly in the summertime when ozone levels are the highest. They also spend more time engaged in vigorous activity, which results in more air—and therefore more pollution—being taken deep into the lungs. Since their lungs are still developing, they breathe more rapidly and inhale more air pollution per pound of body weight than adults.

Travis County Statistics

(Compiled from American Lung Association's State of the Air Report 2005)


TC Total Population Under 18 Over 65 Pediatric Asthma Adult Asthma Chronic Bronchitis Emphysema Cardiovascular Disease Diabetes
857,204 211,607 58,054 18,008 44,170 23,972 6,668 174,297 33,337

Research studies

In June 2001 the American Lung Association published an "Annotated Bibliography of Recent Studies of the Health Effects of Ozone Air Pollution 1997-2001" ( Below are brief highlights of a few of the studies.

Additional Data

During the 1996 Atlanta Summer Olympics, ozone concentrations decreased significantly as a result of the downtown being closed to private cars, increased public transit, and lower traffic congestion. Researchers found significant reductions in emergency care and hospitalizations for asthma among children ages 1-16 years.

  • A study followed 3,300 school children for 10 years in 12 Southern California communities with a variety of air pollution levels. Girls with asthma, and boys who spent more time outdoors, experienced diminished lung function in association with ozone.
  • A 1994-96 study of 1,150 first and second grade children in Austria found that highest and lowest exposure to ozone differed by a factor of two. They found small but consistent decrements in lung function associated with ambient ozone. They concluded: "This is the first study that suggests chronic effects of ozone on lung function growth in children."
  • U.S. West Point Cadets experienced a decline in lung function during summer training at Fort Benning, GA, Fort Leonard Wood, MO, Fort Sill, OK, and Fort Dix, NJ. The greatest decline was in the New Jersey group, where peak hourly ozone concentrations above 100 ppb occurred frequently.
  • A study of 500 nonsmoking Yale college students from around the country found that "living for four or more years in regions of the country with high levels of ozone and related copollutants is associated with diminished lung function and more frequent reports of respiratory symptoms".
  • A study of over 3,000 adults in the nonsmoking Seventh Day Adventist community found that 8-hour ambient ozone concentration averaged over a 20-year period was associated with doctor diagnoses of adult-onset asthma in nonsmoking males.
  • A study of daily admissions to public hospitals in Brisbane, Australia, 1987-94, found that ozone was consistently associated with admissions for asthma and respiratory disease. (ozone levels there are reasonably constant year round)
  • A study found that "contrary to conventional wisdom, ozone is involved in the causation of asthma." The research followed children who played active sports for at least five years, starting at age 9. They found that 265 of the children were diagnosed with asthma during the study, and that those most likely to develop the disease were exercising in the most polluted cities.

The American Lung Association 2005 "State of the Air" Report is available at

Additional clean air information can be found at

700 lavaca sm

Cynthia C. McDonald
County Executive

700 Lavaca Street, 5th Floor
PO Box 1748
Austin, Texas 78767 (Map)

Phone: (512) 854-9383
Fax: (512) 854-4697

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