Airway Sensitivity of Asthmatics To Sulfur Dioxide

Abstract

The purpose of this study was to describe for asthmatic subjects the distribution of individual bronchial sensitivity to sulfur dioxide (SO2). Subjects were nonsmoking male asthmatics (n = 27) who were sensitive to inhaled methacholine. None of the subjects used corticosteroids or cromolyn sodium. Oral medications were with held for 48 hr, inhaled medications for 12 hr prior to all testing. Each subject participated in four separate randomly ordered 10 min exposures to 0.00, 0.25, 0.50 and 1.00 ppm SO₂ at 26° C, 70% relative humidity. During exposures, subjects breathed naturally and performed moderate exercise (V_E, normalized for body surface area = 21 l/m² x min). Before and 3 min after exposure, specific airway resistance (SRaw) was measured by body plethysmography. Those subjects whose SRaw was not doubled by exposure to 1.00 ppm were also exposed to 2.00 ppm S02. Dose response curves (relative change in SRaw, corrected for change in clean air vs S02 concentration) were constructed for each subject. Bronchial sensi tivity to SO₂ [PC(SO2)], defined as the concentration of S02 which provoked an increase in SRaw 100% greater than the response to clean air, was determined. Substantial variability in sensitivity was observed: for 23 subjects, PC(SO2) ranged between 0.28 and 1.90 ppm, while for the remaining 4 subjects, it was greater than 2.00- ppm S02. The median PC(SO2) was 0.75 ppm SO₂, and 6 subjects had a PC(SO₂) of less than 0.50 ppm. PC(SO₂) was not related (r = 0.31) to airway sensitivity to methacholine.

Keywords

2. Key words: asthma bronchial challenge pulmonary function sulfur dioxide.

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References

Bethel, R.A. , Epstein, J. , Sheppard, D. , Nadel, J.A. and Boushey, H.A. (1983). Sufur dioxide-induced bronchoconstriction in freely breathing, exercising, asthmatic subjects Am. Rev. Respir. Dis. 128:987-990.

Bethel, R.A. , Sheppard, D. , Epstein, J. , Tam, E. , Nadel, J.A. and Boushey, H.A. (1984). Interaction of sulfur dioxide and dry cold air in causing bronchoconstriction in asthmatic subjects J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 57:419-423.

Boushey, H.A. , Holtzman, M.J. , Sheller, J.R. and Nadel, J.A. (1980). State of the Art: Bronchial Hyperreactivity. Am. Rev. Respir. Dis. 121:389-423.

Cropp, G.J.A. , Bernstein, I.L. , Boushey, H.A. , Hyde, R.W. , Rosenthal, R.R. , Spector, S.L. and Townley, R.G. (1980). Guidelines for bronchial inhalation challenges with pharmacologic and antigenic agents ATS News Spring: 1-19.

Dubois, A.B. , Botelho, S.Y. and Comroe, J.H. (1956). A new method for measuring airway resistance in man using a body plethysmograph: values in normal subjects and in patients with respiratory disease J. Clin. Invest. 35:327-335.

Haynes, R.L. , Ingram, R.H. and Mcfadden, E.R. (1976). An assessment of the pulmonary response to exercise in asthma and an analysis of the factors influencing it Amer. Rev. Resp. Dis. 114:739-752.

Hazucha, M.J. , Ginsberg, J.F. , Mcdonnell, W.F. , Haak, E.D. , Pimmel, R.L. , Salaam, S.A. , House, D.E. and Bromberg, P.A. (1983). Effects of 0.1 ppm nitrogen dioxide on airways of normal and asthmatic subjects J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 54:730-739.

Knudson, R.J. , Slatin, R.C. , Lebowitz, M.D. and Burrows, B. (1976). The maximal expiratory flow-volume curve. Normal standards, variability, and effects of age Am. Rev. Respir. Dis. 113:587-600.

Leaderer, B.P. (1982). Air pollutant emissions from kerosene space heaters Science 218:1113-1118.

10.

Linn, W.S. , Shamoo, D.A. , Spier, C.E. , Valencia, L.M. , Anzar, U.T. , Venet, T.G. and Hackney, J.D. (1983a). Respiratory effects of 0.75 ppm sulfur dioxide in exercising asthmatics: influence of upper-respiratory defenses. Environ. Res. 30:340-348.

11.

Linn, W.S. , Venet, T.G. , Shamoo, D.A. , Valencia, L.M. , Anzar, U.T. , Spier, C.E. and Hackney, J.A. (1983b). Respiratory effects of sulfur dioxide in heavily exercising asthmatics. Am. Rev. Respir. Dis. 127:278-283.

12.

Mcdonnell, W.F. , Horstman, D.H. , Hazucha, M.J. , Seal, E. , Haak, E.D. , Salaam, S.A. and House, D.E. (1983). Pulmonary effects of ozone exposure during exercise: dose-response characteristics J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 54:1345-1352.

13.

Roger, L.J. , Kehrl, H.R. , Hazucha, M. AND Horstman, D.H. (1985). Bronchoconstriction in asthmatics exposed to sulfur dioxide during repeated exercise. J. Appl. Physiol. 59:784-791.

14.

Sheppard, D. , Eschenbacher, W.L. , Boushey, H.A. and Bethel, R.A. (1984). Magnitude of the interaction between the bronchomotor effects of sulfur dioxide and those of dry (cold) air Am. Rev. Respirat. Dis 130:52-55.

15.

United States Environmental Protection Agency. ( 1985). Air Quality Criteria for Particulate Matter and Sulfur Dioxide, Vol. II (EPA publication no. 600/ 8-82-029b). Chapter 5.