Effects fo sulfuric acid aerosol on respiratory mechanics and mucociliary particle clearance in healthy and asthmatic adults

Thesis/Dissertation · Wed Dec 31 23:00:00 EST 1980

OSTI ID:6593579

Leikauf, G D

The effects of submicrometer sulfuric acid (H/sub 2/SO/sub 4/) aerosol on human pulmonary physiology were investigated. Eighteen healthy and 10 asthmatic subjects inhaled H/sub 2/SO/sub 4/ via nasal mask for 1 hour at concentrations of 0, 100, 300 and 1000 ..mu..g/m/sup 3/ in a random sequence. The aerosol size (0.5 ..mu..m) and lower exposure level (100 ..mu..g/m/sup 3/) were selected to simulate peak ambient conditions, while the upper exposure concentration (1000 ..mu..g/m/sup 3/) is comparable to the current occupational limit for chronic exposure. Bronchial mucociliary clearance was markedly altered in all but one of the healthy subjects following one or more of the H/sub 2/SO/sub 4/ inhalations. The mucus was tagged by having each subject inhale either a 7.6 or 4.2 ..mu..m radiolabeled Fe/sub 2/O/sub 3/ aerosol. Exposure to 1000 ..mu..g/m/sup 3/ H/sub 2/SO/sub 4/ produced a delay in clearance which lasted longer in the group of eight inhaling the smaller 4.2 ..mu..m Fe/sub 2/O/sub 3/ aerosol than in the group of ten inhaling 7.6 ..mu..m Fe/sub 2/O/sub 3/. At 100 ..mu..g/m/sup 3/, the groups differed to a greater extent with clearance of the more centrally deposited larger aerosol being stimulated and that of the distally deposited smaller aerosol being transiently inhibited. Tracheal clearance remained unchanged in both groups. These findings, along with calculations of the various aerosols' deposition patterns, indicate that H/sub 2/SO/sub 4/ exerted a greater effect in the distal airways than in the proximal airways. Slight changes in ventilatory mechanics were noted in the asthmatic subjects following the 1000 ..mu..g/m/sup 3/ H/sub 2/SO/sub 4/ exposure, an effect not observed in the healthy subjects. However, the results obtained in the asthmatic group for tests of mucociliary clearance failed to reach significance, possible due to the large variability of such measurements in groups with respiratory disease.

• OSTI ID: 6593579
• Country of Publication: United States
• Language: English

Related Subjects

560306* -- Chemicals Metabolism & Toxicology-- Man-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AEROSOLS
ASTHMA
BODY
BRONCHI
CLEARANCE
COLLOIDS
DISEASES
DISPERSIONS
EXCRETION
HYDROGEN COMPOUNDS
INHIBITION
INORGANIC ACIDS
LUNG CLEARANCE
LUNGS
ORGANS
RESPIRATION
RESPIRATORY SYSTEM
RESPIRATORY SYSTEM DISEASES
SOLS
SULFURIC ACID
VARIATIONS