Perceptual and psychophysiological responses of non-smokers to a range of environmental tobacco smoke concentrations

To estimate the perceptual, psychophysiological and cognitive impact of environmental tobacco smoke (ETS) on non-smokers, seventeen male never-smokers, ages 21-33, were exposed to five concentrations yielding mean ETS-respirable suspended particles (RSP) levels of 58, 113, 217, 368, and 765 mu g/m(3). During each 90-minute session, four smokers were seated behind a partition and smoked, when cued, to generate 70-minute exposures. For control exposures, smokers ''puffed'' on unlit cigarettes. Odor Strength, Annoyance, Overall Acceptance and Eye Irritation at the lowest level were significantly different from control values and the degree of change generally increased monotonically with ETS level. Fatigue was not affected by any ETS level. Odor Strength (rated highest of all attributes at all levels) at the 217 mu g/m(3) ETS-RSP level was 12.5% of the maximum odor intensity experienced prior to the study. No effect of ETS on information processing was observed. Psychological state and eye blink rate were affected at only the 765 mu g/m(3) ETS-RSP level. During times when the participants were not completing a questionnaire or test, all ETS levels resulted in a 5-8% decrease in respiratory rate, due largely to an increase in expiratory duration, but no change in minute ventilation. The breathing changes may represent a psychophysiological response mediated by the olfactory system. Non-smokers are aware of ETS at ETS-RSP concentrations as low as 58 mu g/m(3) (similar to 80-fold higher than the level typical of current U.S. workplace environments where smoking is permitted) but its sensory impact remains relatively small until ETS-RSP concentrations above 217 mu g/m(3) are encountered.