DETECTABILITY AND PERCEIVED INTENSITY FOR FORMALDEHYDE IN SMOKERS AND NONSMOKERS

Formaldehyde emanating from cigarette smoke and en-fissions from building materials is an important contaminant of indoor air and an interesting gaseous compound in the study of smokers' sensitivity to odor. With the aid of hood exposures to 18 formaldehyde concentrations (7.5 to 1000 ppb), odor detection thresholds (method of constant stimuli) and perceived odor intensities (method of magnitude estimation) were determined among heavy cigarette smokers (22 women) and non-smokers (22 aged-matched women). To adjust for individual differences in response behavior, the odor thresholds were corrected for false alarms resulting from purified air presentations and the scale values of odor intensity were calibrated according to the master scale principle using loudness of pink noise as a reference scale [42 to 96 dB(A)]. The results showed significantly higher odor detection thresholds for smokers than for non-smokers, 94 and 55 ppb, respectively, and significantly lower odor intensities reported by smokers than non-smokers. In evaluating the observers' audiograms, the smokers displayed significantly higher thresholds of hearing than the non-smokers. The results support the possibility that habitual cigarette smoking may result in decreased sensitivity of sensory systems in general.