Respiratory Effects of Secondhand Smoke—Reply

In Reply: We are pleased to see that the human exposure data from the R. J. Reynolds Tobacco Company Bowman Gray Technical Center also confirm an acute decrement in lung function following controlled experimental human exposures to sidestream tobacco smoke. We would encourage Drs Smith and Sears to publish these findings in full. Previous exposure chamber data have suggested that adults with asthma may experience even greater declines in airflow following exposure to environmental tobacco smoke,^1- 2 and a more recent study also observed changes in airway responsiveness in some asthmatic adults exposed under laboratory conditions.³ Any association between controlled sidestream tobacco smoke and triglycerides and HDL may have a variety of correlates, including circulating catecholamines. One would assume, however, that increased catecholamines, if anything, would produce bronchodilation, thus increasing airflow. An earlier chamber study that specifically investigated the question did not find that subject suggestibility had a meaningful contribution to the physiologic responses to secondhand smoke.⁴ The known direct irritants in secondhand smoke provide substantial biologic plausibility for acute airway symptoms and obstruction following this exposure.