Document Detail

Oxidant and acid aerosol exposure in healthy subjects and subjects with asthma. Part I: Effects of oxidants, combined with sulfuric or nitric acid, on the pulmonary function of adolescents with asthma.
MedLine Citation:
PMID:  7848586     Owner:  NLM     Status:  MEDLINE    
Both peak flow decrements in children at summer camps and increased hospital admissions for asthma have been associated with summer "acid haze," which is composed of ozone and various acidic species. The objective of this study was to investigate the pulmonary effects of acid summer haze in a controlled laboratory setting. Twenty-eight adolescent subjects with allergic asthma, exercise-induced bronchospasm, and a positive response to a standardized methacholine challenge enrolled in the study; 22 completed the study. Each subject inhaled one of four test atmospheres by mouthpiece on two consecutive days. The order of exposure to the four test atmospheres was assigned via a random protocol: air, oxidants (0.12 parts per million [ppm]* ozone plus 0.30 ppm nitrogen dioxide), oxidants plus sulfuric acid at 70 micrograms/m3 of air, or oxidants plus 0.05 ppm nitric acid. Exposure to each of the different atmospheres was separated by at least one week. The exposures were carried out during alternating 15-minute periods of rest and moderate exercise for a total exposure period of 90 minutes per day. Pulmonary function was measured before and after exposure on both test days and again on the third day as a follow-up measurement. A postexposure methacholine challenge was performed on Day 3. Low methacholine concentrations were chosen for the postexposure challenge to avoid provoking a response. The protocol was designed to detect subtle changes in airway reactivity. The statistical significance of the pulmonary function values was tested using paired t tests. First, we compared the difference between baseline and postexposure measurements after air exposure on Day 1 with the differences between baseline and postexposure measurements after Day 1 exposure to each of the other three atmospheres. Second, we compared the difference between baseline and postexposure measurements after the Day 2 air exposure with the differences between baseline and postexposure measurements after the Day 2 exposure to each of the pollutant atmospheres. Third, we compared the difference between baseline measurements on Day 1 of each exposure atmosphere with measurements after exposure to the same atmosphere on Day 2 to detect delayed effects. No changes in any of the pulmonary function parameters were statistically significant when compared with changes after clean air exposure. Six subjects left the study because of uncomfortable symptoms associated with the exposures. These all occurred after exposure to pollutant atmospheres and not after exposure to clean air.(ABSTRACT TRUNCATED AT 400 WORDS)
J Q Koenig; D S Covert; W E Pierson; Q S Hanley; V Rebolledo; K Dumler; S E McKinney
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Randomized Controlled Trial; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Research report (Health Effects Institute)     Volume:  -     ISSN:  1041-5505     ISO Abbreviation:  Res Rep Health Eff Inst     Publication Date:  1994 Nov 
Date Detail:
Created Date:  1995-03-14     Completed Date:  1995-03-14     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8812230     Medline TA:  Res Rep Health Eff Inst     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  1-36     Citation Subset:  IM    
School of Public Health and Community Medicine, Department of Environmental Health, University of Washington, Seattle 98195.
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MeSH Terms
Acid Rain
Air Pollutants / adverse effects*
Asthma / physiopathology*
Bronchial Hyperreactivity / physiopathology
Bronchial Spasm / physiopathology
Follow-Up Studies
Hypersensitivity / physiopathology
Lung / drug effects*,  physiopathology*
Nitric Acid / administration & dosage,  adverse effects*
Nitrogen Dioxide / administration & dosage,  adverse effects
Oxidants / administration & dosage,  adverse effects*
Ozone / administration & dosage,  adverse effects
Physical Exertion / physiology
Sulfuric Acids / administration & dosage,  adverse effects*
Reg. No./Substance:
0/Acid Rain; 0/Aerosols; 0/Air Pollutants; 0/Oxidants; 0/Sulfuric Acids; 10028-15-6/Ozone; 10102-44-0/Nitrogen Dioxide; 7697-37-2/Nitric Acid

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