Respiratory Effects of Secondhand Smoke

To the Editor: The pulmonary function changes reported by Dr Eisner and colleagues¹ are quantitatively similar to those previously observed by our laboratory.² In our 5-day environmental room study on 20 healthy subjects who had never smoked (10 men and 10 women, aged 21-50 years), a 7.33-hour exposure to 179 µg/m³ of respirable suspended particles of fresh diluted sidestream smoke generated by a machine that was smoking 1R4F Kentucky reference cigarettes resulted in the following exposure-related statistically significant decreases: forced ventilatory capacity (−1.7%), forced expiratory volume in 1 second (−1.6%), and forced expiratory flow [FEF_0.2-1.2, subscript indicating the volume segment of 200 mL to 1200 mL in adults] (−4.4%). These same subjects may have experienced an exposure-related increase in epinephrine release as evidenced by an increase in triglyceride level and decrease in high-density lipoprotein (HDL) cholesterol level, results consistent with a sensory-mediated epinephrine-induced mobilization of free fatty acids and concomitant lowering of HDL. Therefore, it is plausible that the observed decreases in pulmonary function may have been related also to sensory-mediated epinephrine release.