Project at a Glance

Title: Effects of ozone on the asthmatic airway.

Principal Investigator / Author(s): Nadel, J A

Contractor: Cardiovascular Research Institute, UC San Francisco

Contract Number: A3-112-33

Research Program Area: Health & Exposure

Topic Areas: Health Effects of Air Pollution, Vulnerable Populations


The purpose of these studies was to investigate various aspects of ozone effects in airways and to determine the mechanisms of these effects. The first group of studies in humans were designed to determine whether asthmatic subjects had a heightened sensitivity to ozone compared to normal, healthy individuals. 'These studies were carried out with a sequence of protocols to prevent excessive risks to the subjects. The results, taken together, do not suggest any striking difference between asthmatics and normal subjects in regard to airway responses to inhaled ozone. The second series of human studies were an extension of previous animal studies, designed to determine whether humans develop an inflammatory response to inhaled ozone similar to dogs. The studies confirm the animal studies and suggest mechanisms by which ozone and other oxidant pollutants may cause changes in lung function. The third group of investigations dealt with the mechanisms by which ozone induces airway hyper responsiveness. As in the past, we initiated the studies in animals, with the intention of applying the results to human investigations as soon as possible. The animal studies involved a series of experiments which demonstrated that airway epithelial damage (e.g., by oxidants) is capable of producing lipids that act as "mediators," initiating inflammatory responses. Among these responses is neutrophil mobilization into the airways. Subsequent activation of the neutrophils results in the production of more mediators that appear to be responsible for the final airway smooth muscle responses. Finally, we have discovered drugs that have the potential to prevent the effects of ozone in this system.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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