Lack of bronchoconstrictor response to sulfuric acid aerosols and fogs

Journal Article · Mon Apr 01 00:00:00 EST 1991 · American Review of Respiratory Disease (New York); (USA)

DOI:https://doi.org/10.1164/ajrccm/143.4_Pt_1.744· OSTI ID:5799343

Aris, R; Christian, D; Sheppard, D; Balmes, J R ^[1]

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

Sulfuric acid (H{sub 2}SO{sub 4}) is the most common acid air pollutant in the United States and is thought to have adverse respiratory effects. Sulfuric acid exists in polluted air as a dissolved solute in both small (haze) and large (fog) particles. Previous work in our laboratory has failed to demonstrate bronchoconstriction after near ambient, large-particle H{sub 2}SO{sub 4} exposure in subjects with asthma. However, other investigators have found slight but significant changes in lung function following inhalation of small-particle or small-particle, low-relative-humidity (RH) H{sub 2}SO{sub 4} aerosols, leading us to hypothesize that particle size and/or RH may be important variables in acid aerosol exposure. We initially studied the effects of resting inhalation of large-particle (volume median diameter, VMD, approximately equal to 6 microns) and small-particle (VMD approximately equal to 0.4 microns) aerosols with an H{sub 2}SO{sub 4} concentration of 3 mg/m3 through a mouthpiece and found no effect on specific airway resistance (SRaw) or symptom scores. In a second mouthpiece study designed to compare high-RH (100%), large-particle (VMD approximately equal to 6 microns) and low-RH (less than 10%), small-particle (VMD approximately equal to 0.3 microns) aerosols with an H{sub 2}SO{sub 4} concentration of 3 mg/m3, we again found no effect of either aerosol. We then examined the effects of small-particle aerosols inhaled in dry air during moderate exercise. Although breathing low-RH air during exercise provoked increases in SRaw in almost all subjects, this could not be attributed to H{sub 2}SO{sub 4} since low-RH saline aerosol produced a similar result.

• OSTI ID: 5799343
• Journal Information: American Review of Respiratory Disease (New York); (USA), Vol. 143:4 Pt 1; 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.
LUNGS
SENSITIVITY
SULFURIC ACID
TOXICITY
AEROSOLS
AIR POLLUTION
HUMIDITY
INHALATION
METABOLISM
PARTICLE SIZE
VASOCONSTRICTION
BODY
COLLOIDS
DISPERSIONS
HYDROGEN COMPOUNDS
INORGANIC ACIDS
INTAKE
ORGANS
POLLUTION
RESPIRATORY SYSTEM
SIZE
SOLS
560300* - Chemicals Metabolism & Toxicology