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Updated: Jun 27, 2026

A Free-breathing fMRI Method to Study Human Olfactory Function
Published on: July 30, 2017
[Study of olfactory function for pyridine in healthy population: influence of variations in humidity]
José Ignacio Alfonso Collado1, Héctor Vallés Varela
1Hospital Clínico Universitario Lozano Blesa. Zaragoza. España. alfit@telefonica.net
Objectives:
We study the influence of humidity and its variations on human olfactory threshold for pyridine.
Material And Method:
Olfactory function was tested on 154 healthy volunteers without rhino-sinusal pathology. Pyridine was used as odorant in four different concentrations investigating the ability to detect the stimulus and the acuity to estimate its intensity. All subjects were exposed to four pre-set concentrations of pyridine and their ability to detect the stimulus and its intensity was assessed. We measured the variations in ambient humidity and evaluated its effects on the results.
Results:
A total of 154 healthy volunteers between 20 and 60 years old (69 men and 85 women) were tested for different concentrations of pyridine with an ambient humidity variation of 50 % +/- 20 %. The average humidity was 50.74 % with a standard deviation of 4.95 %. We did not find significant differences (P>.05) for mean humidity measures between volunteers who detected the odorant and those who did not. Nor did we find significant differences when estimating intensity.
Conclusions:
We did not find any effect of ambient humidity variation between 42 % and 67 % on human olfactory sensitivity for pyridine.
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