| Autor: |
Morrow, P. E., Utell, M. J., Bauer, M. A., Speers, D. M., Gibb, F. R. |
| Zdroj: |
Annals of Occupational Hygiene; 1994 Inhaled Particles VII, Vol. 38, p933-938, 6p |
| Abstrakt: |
To determine if near ambient levels of sulphuric acid aerosols, H2SO4, induce reductions in lung function in subjects with obstructive lung disease, 17 volunteers with asthma (age range 20–57 years) and 17 subjects with chronic obstructive pulmonary disease (COPD) (age range 52–70 years) were exposed to H2SO4 in a 45 m3 environmental chamber. All asthmatics showed evidence of mild obstructive lung disease [baseline FEV1/FVC = 0.65±0.09 (SD)]. COPD selection criteria were dyspnea on exertion, obstructive airways disease (FEV1/FVC = 0.56±0.09) and a lack of response to inhaled bronchodilators. By double-blind randomization, each subject inhaled either 100±μg m−3 NaCl (control) aerosol or 90±10 μg m−3 unencumbered breathing for a 2-h period on occasions separated by at least 1 week. On a bicycle ergometer, all subjects exercised for 10 min at work loads sufficient to at least quadruple minute ventilation after 10, 35, 60 and 90 min of exposure. We measured before, during and immediately after exposure FVC, FEV7, specific airway conductance (SGaw) and arterial oxygen saturation. Neither NaCl (control) nor H2SO4 exposure during exercise caused a significant decrease in FVC, FEV1 or SGaw from baseline in subjects with COPD. Although no statistical significant differences in per cent change in FVC were seen on control vs H2SO4 exposure days in asthmatic subjects, small reductions in FEV1 and SGaw (P < 0.02) from baseline were found after exercise during the exposure when compared to the NaCl exposure by cross-over t-tests. These findings suggest that near ambient levels of H2SO4 do not affect lung function in subjects with COPD but that adult asthmatic subjects may develop a mild increase in exercise-induced bronchospasm. [ABSTRACT FROM PUBLISHER] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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