Effects of Chronic Ozone Exposure on Lung Function

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00006306
First received: September 28, 2000
Last updated: January 27, 2006
Last verified: January 2006

September 28, 2000
January 27, 2006
September 1999
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Complete list of historical versions of study NCT00006306 on ClinicalTrials.gov Archive Site
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Effects of Chronic Ozone Exposure on Lung Function
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To determine the effects of chronic ozone exposure on lung function in young men and women.

BACKGROUND:

A large part of the U.S. population is exposed to ambient ozone (O3) concentrations that are associated with acute respiratory health effects; however, little is known about the effects on human respiratory health of long-term exposure to such ambient concentrations. Chronic exposure of non-human primates to high concentrations of O3 are associated with pathologic changes in the centriacinar region of the lung that are similar to changes observed in young cigarette smokers. This is the first detailed epidemiologic study of the effects of chronic exposure to an air pollutant based on individual estimates of lifetime exposure and controlled exposure data. The study tests a specific toxicologic model in humans that has relevance for chronic respiratory disease and explores mechanisms of effects.

DESIGN NARRATIVE:

The study tested the hypothesis that, in humans, there was an exposure-response relationship between the amount of chronic exposure to ambient O3 and measures of lung function that reflected changes in the centriacinar region of the human lung (FEF25-75); and this relationship was not seen with measures of more proximal airway function (FEV1). First-year UC Berkeley students, ages 18-21 yrs, who were lifelong residents of the Los Angles Basin, (high O3) and the San Francisco Bay Area, (low O3) were studied. Lifetime exposure to ambient O3 was estimated with methods developed by the investigators that combined questionnaire and ambient O3 data. Lung function was assessed with maximum expiratory flow-volume curves. Students were studied after 4-6 months of low ambient O3 exposure and immediately after 2-3 months of exposure to summertime O3. Students from each area who were at the upper and lower tails of the FEF25-75 distribution underwent two controlled O3 exposures (seasonal as above) followed by bronchoalveolar lavage/biopsy to evaluate relationships between measures of inflammation, injury/repair and oxidant induced damage/repair and FEF25-75. Regression was used to evaluate relationships between lifetime O3 exposure and lung function, adjusted for past and family respiratory history, allergy history, home characteristics, exposure to environmental tobacco smoke and particle air pollution and NO2.

Observational
Observational Model: Defined Population
Time Perspective: Longitudinal
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  • Lung Diseases
  • Lung Diseases, Obstructive
  • Chronic Obstructive Pulmonary Disease
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Tager IB, Balmes J, Lurmann F, Ngo L, Alcorn S, Kunzli N. Chronic exposure to ambient ozone and lung function in young adults. Epidemiology. 2005 Nov;16(6):751-9.

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
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August 2004
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No eligibility criteria

Both
18 Years to 21 Years
No
Contact information is only displayed when the study is recruiting subjects
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NCT00006306
134
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National Heart, Lung, and Blood Institute (NHLBI)
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Investigator: Ira Tager University of California, Berkeley
National Heart, Lung, and Blood Institute (NHLBI)
January 2006

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP