THE ACUTE EFFECT OF ENVIRONMENTAL TOBACCO-SMOKE EXPOSURE ON ASTHMATICS - STUDIES WITH A DYNAMIC CHALLENGE CHAMBER

To determine the acute effects of environmental tobacco smoke on respi ratory tract lung function, 130 asthmatics and 28 non-asthmatics were exposed up to 4 hours to side stream environmental tobacco smoke (SS-E TS) in a dynamic challenge chamber. The vast majority of the subjects exposed to SS-ETS reported upper respiratory and ocular irritant sympt oms; the prevalence of these symptoms was not significantly associated with any particular study groups analyzed, or with the self-perceptio n of tobacco smoke allergy by the study subject. All 28 SS-ETS-exposed non-asthmatics had no significant change in lung function, while 26/1 30 asthmatics demonstrated a significant drop in pulmonary function (F EV1 greater than or equal to 20% decline), generally within 90 to 240 minutes after start of exposure. Classical late phase bronchoconstrict ion was not observed up to 24 hours following the challenge. Six/26 re actors had a significant drop in lung function following a sham contro l challenge, indicating that 20/130 asthmatics had a specific bronchoc onstrictive response to SS-ETS. Responses to diminishing levels of SS- ETS demonstrated that some asthmatics can react to levels as low as 0. 0128 cigarette - min/m(3) (comparable to ETS levels in the homes of ma ny smokers). (C) Indoor Air (1997).