Response to acute ozone exposure in healthy men. Results of a screening procedure
Autor: | Allyn W. Kimball, G. G. Weinmann, Robert Frank, Stephen M. Bowes, Margaret W. Gerbase |
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Rok vydání: | 1995 |
Předmět: |
Adult
Male Pulmonary and Respiratory Medicine Atmosphere Exposure Chambers medicine.medical_specialty Time Factors Adolescent Vital Capacity Physiology Maximal Midexpiratory Flow Rate Critical Care and Intensive Care Medicine Volume correction FEV1/FVC ratio Ozone Reference Values Forced Expiratory Volume medicine Humans Ozone exposure skin and connective tissue diseases Exercise business.industry Confounding respiratory system respiratory tract diseases Surgery Spirometry Time course Linear Models Respiratory Mechanics Multiple linear regression analysis sense organs business circulatory and respiratory physiology |
Zdroj: | American Journal of Respiratory and Critical Care Medicine. 151:33-40 |
ISSN: | 1535-4970 1073-449X |
DOI: | 10.1164/ajrccm.151.1.7812569 |
Popis: | We screened 64 healthy, nonsmoking men, 18 to 35 yr old, for their sensitivity to 0.35 ppm ozone (O3) administered for 130 to 150 min with intermittent exercise. The changes in FVC, FEV1, AND FEF25-75 (p0.0001) immediately after O3 exposure varied widely among subjects. Histograms of the percentage changes in FVC and FEV1 did not differ from a unimodal, skewed (gamma) distribution (p = 0.99 and p = 0.17, respectively); the changes in FEF25-75 tended to deviate from a gamma distribution (p = 0.055). To adjust FEF25-75 for the confounding effects of O3 on FVC, we used multiple linear regression analysis with contemporaneous FVC as a covariable, analysis of a subgroup of nine subjects whose O3-induced FVC changes wereor = 5%, and volume correction of FEF25-75 for any changes in FVC after exposure. These analyses showed reductions in FEF25-75 unexplained by and following a different time course than the O3-induced changes in FVC. In 26 subjects also exposed to filtered air, significant effects of O3 on respiratory frequency (p0.004) and tidal volume (p0.0007) correlated weakly with FVC changes. The results confirm the wide variability in spirometric responsiveness among individuals to O3 and suggest that intrinsic narrowing of the small airways may be a significant component of the functional response. |
Databáze: | OpenAIRE |
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