Short-term exposure to 0. 3 ppm nitrogen dioxide does not potentiate airway responsiveness to sulfur dioxide in asthmatic subjects

Journal Article · Thu Feb 01 00:00:00 EST 1990 · American Review of Respiratory Disease (New York); (USA)

DOI:https://doi.org/10.1164/ajrccm/141.2.381· OSTI ID:6991972

Rubinstein, I; Bigby, B G; Reiss, T F; Boushey, Jr, H A ^[1]

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1. Univ. of California, San Francisco (USA)

Whether short-term exposure to low levels of nitrogen dioxide (NO2) enhances airway responsiveness in asthmatic subjects is controversial. Because it is well established that asthma is associated with increased airway responsiveness to another common air pollutant, sulfur dioxide (SO2), we examined whether short-term exposure of asthmatic subjects to 0.3 ppm NO2 potentiates airway responsiveness to inhaled SO2. We exposed nine subjects with clinically stable asthma to 0.3 ppm NO2 or filtered air in an environmental room for 30 min on 2 separate days at least 1 wk apart in a double-blind, randomized fashion. A questionnaire about common symptoms related to inhaled irritants was completed before and immediately after each exposure. Each subject exercised (60 to 80 W) on a cycloergometer during the first 20 min of each exposure. We measured specific airway resistance (SRaw) and FEV1/FVC before, 5 min after, and 1 h after completion of the air or NO2 exposure. The single-breath nitrogen test (SBN2) was also performed before and 1 h after completion of the air or NO2 exposures and closing volume was determined; subsequently, SO2 dose-response curves (0.25 to 4.0 ppm) were performed via a mouthpiece. Each dose of SO2 was inhaled at a minute ventilation of 20 L/min for 4 min and was doubled until SRaw increased by at least 8 U above baseline. The dose of SO2 required to provoke an increase in SRaw of 8 U above baseline was determined by linear interpolation from the dose-response curve (PD8Uso2).

• OSTI ID: 6991972
• Journal Information: American Review of Respiratory Disease (New York); (USA), Vol. 141:2; ISSN 0003-0805
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ASTHMA
PATHOGENESIS
NITROGEN DIOXIDE
TOXICITY
SULFUR DIOXIDE
AIR POLLUTION
DOSE-RESPONSE RELATIONSHIPS
ENVIRONMENTAL EXPOSURE
INHALATION
MAN
SYNERGISM
ANIMALS
CHALCOGENIDES
DISEASES
INTAKE
MAMMALS
NITROGEN COMPOUNDS
NITROGEN OXIDES
OXIDES
OXYGEN COMPOUNDS
POLLUTION
PRIMATES
RESPIRATORY SYSTEM DISEASES
SULFUR COMPOUNDS
SULFUR OXIDES
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology