Airway reactivity to nitrates in normal and mild asthmatic subjects
Epidemiologic studies have reported increased symptoms in young asthmatics when atmospheric pollutants containing nitrates and sulfates are elevated. To determine if inorganic nitrate pollutants cause increased airway reactivity in humans, 10 normal volunteers and 11 mild asthmatics inhaled a sodium nitrate (NaNO/sub 3/) aerosol with an aerodynamic diameter of 0.46 ..mu..m at a concentration of 7000 ..mu..g/m/sup 3/, a level 100-1000 times greater than reported urban levels for nitrates. A sodium chloride (NaCl) aerosol of similar characteristics served as a control. By double-blind randomization, each subject breathed NaCl or NaNO/sub 3/ for a 16-min period and again 2 to 4 h later. Deposition studies showed 32 to 78% retention of the inhaled aerosol. Functional residual capacity, airway resistance, forced vital capacity, 1-s forced expiratory volume, and maximum and partial expiratory flow rates at 60 and 40% of total lung capacity did not significantly change during or after exposure. All subjects remained asymptomatic. To establish if aerosol exposure increased reactivity to a known bronchoconstrictor, subjects inhaled 0.025 to 1.0% carbachol following the 16-min exposure. Although prior inhalation of NaNO/sub 3/ or NaCl aerosols did not significantly alter the effect of carbachol on pulmonary function, two asthmatics demonstrated mild potentiation of the carbachol bronchoconstrictor response after nitrate exposure. These results suggest that in normal subjects and mild asthmatics short-term NaNO/sub 3/ exposure does not alter pulmonary function.
- Research Organization:
- Univ. of Rochester School of Medicine, NY
- OSTI ID:
- 5843551
- Journal Information:
- J. Appl. Physiol.; (United States), Vol. 46:1
- Country of Publication:
- United States
- Language:
- English
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63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
LUNGS
DYNAMIC FUNCTION STUDIES
NITRATES
AEROSOLS
SULFATES
AIR POLLUTION
ASTHMA
MAN
ANIMALS
BODY
COLLOIDS
DISEASES
DISPERSIONS
MAMMALS
NITROGEN COMPOUNDS
ORGANS
OXYGEN COMPOUNDS
POLLUTION
PRIMATES
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
SOLS
SULFUR COMPOUNDS
VERTEBRATES
551000* - Physiological Systems
560306 - Chemicals Metabolism & Toxicology- Man- (-1987)