Controlled exposures of young asthmatics to mixed oxidant gases and acid aerosol
Autor: | Karen R. Anderson, T L Webb, Deborah A. Shamoo, S A Edwards, Henry Gong, Jack D. Hackney, William S. Linn |
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Rok vydání: | 1995 |
Předmět: |
Pulmonary and Respiratory Medicine
Male Atmosphere Exposure Chambers Ozone Adolescent Mineralogy Critical Care and Intensive Care Medicine chemistry.chemical_compound Animal science Oxidants Photochemical Forced Expiratory Volume Respiration medicine Humans Nitrogen dioxide Lung volumes Respiratory system Child Asthma Air Pollutants business.industry Sulfuric Acids medicine.disease Aerosol Respiratory Function Tests chemistry Breathing Female business |
Zdroj: | American journal of respiratory and critical care medicine. 152(3) |
ISSN: | 1073-449X |
Popis: | To help assess short-term respiratory responses to summertime air pollution, we exposed 24 asthmatic volunteers aged 11-18 in a chamber to respirable acid aerosol (mass median aerodynamic diameter 0.66 micron) plus 0.3 ppm nitrogen dioxide (NO2) plus 0.2 ppm ozone (O3). The aerosol contained available hydrogen ions (H-) at an average concentration of 2.6 mumol/m-, equivalent to 127 micrograms/m3 sulfuric acid (H2SO4); some H+ probably was in NH4HSO4 rather than H2SO4. The volunteers were exposed separately to O3/NO2 without acid and to clean air. Exposures lasted 90 min, including three 15-min exercise sessions with ventilation averaging 32 L/min, at 21 degrees C and 50% relative humidity. Asthma medications were withheld before and during exposures. Subjects gargled lemonade to minimize acid neutralization by oral ammonia (NH3). Exercise-induced bronchospasm was evident in all exposures. Differences in group mean lung function response among H2SO4/O3/NO2, O3/NO2, and clean-air exposures were not statistically significant. Individuals' measured oral NH3 concentrations or estimated inhaled doses of H2SO4 did not significantly predict their lung function changes. A few subjects showed unfavorable function changes during pollutant exposures, which might be chance occurrences or might indicate the existence of an acid-pollution-susceptible subgroup among young asthmatic subjects. |
Databáze: | OpenAIRE |
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