| Abstract: | Abstract To determine the acute effects of environmental tobacco smoke on respiratory tract lung function, 130 asthmatics and 28 non-asthmatics were exposed up to 4 hours to side stream environmental tobacco smoke (SS-ETS) in a dynamic challenge chamber. The vast majority of the subjects exposed to SS-ETS reported upper respiratory and ocular irritant symptoms; the prevalence of these symptoms was not significantly associated with any particular study groups analyzed, or with the self-perception of tobacco smoke allergy by the study subject. All 28 SS-ETS-exposed non-asthmatics had no significant change in lung function, while 26/130 asthmatics demonstrated a significant drop in pulmonary function (FEV1≥20% decline), generally within 90 to 240 minutes after start of exposure. Classical late phase bronchoconstriction was not observed up to 24 hours following the challenge. Six/26 reactors had a significant drop in lung function following a sham control challenge, indicating that 20/130 asthmatics had a specific bronchoconstrictive 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/m3 (comparable to ETS levels in the homes of many smokers). |
