Influence of temperature on olfactory sensitivity

¹ Department of Food Sciences and Nutrition, Stanford Research Institute, Menlo Park, California

The olfactory response to acetic acid was studied at six experimental temperatures (12.5, 15, 20, 25, 30, and 35 C) for a trained panel of ten subjects. Determination of the 50% thresholds indicated no significant differences in olfactory sensitivity at the various environmental temperatures. Further analysis of the data indicated two significantly different groups of differing absolute sensitivity; however, no influence of temperature on olfactory sensitivity was noted. The 50% threshold for acetic acid was found to be 39.0 x 10^–4 mg/liter air (0.65 x 10^–7 moles/liter air) for the pooled data. Temperature recordings of inhaled and exhaled air in the nasal cavity suggested inspired air was rapidly equilibrated with body temperature by heat provided by the conchae. These data corroborate the conclusions of the sensory tests and explain the lack of change in odor threshold at different environmental temperatures. The inspired air stream is rapidly warmed to body temperature and any apparent changes in olfactory sensitivity would appear to be physical phenomena and not response to a true olfactory stimulus.