US EPA

725524 

Journal Article 

Effects of Chemical Exposure on Olfaction in Humans 

Amoore, J 

1986 

NIOSH/00165612 

C 

155 - 190 

The effects of chemical exposure on olfaction in humans are reviewed. Studies on determining the normal range of smell sensitivity are described. It is noted that many methods have been developed for measuring the sensitivity of olfaction, but no widely recognized standard has emerged. The author recommends using serial dilutions of pyridine in water or mineral oil for measuring olfactory thresholds. Studies in normal adults having no known nasal pathology and no significant industrial exposure show that the threshold for detecting pyridine ranges from 20 to 0.04 parts per million. The sensitivities constitute a nearly normal Gaussian distribution with a mean threshold at step 18.07 and a standard deviation of 1.76 steps. Chemically induced hyposmia is discussed. Chemicals which after acute or chronic exposure induce temporary, recuperable, or permanent hyposmias are tabulated. Nearly 120 substances including reactive chemical vapors such as formaldehyde (50000) and hydrogen-sulfide (7783064), solvents such as acetone (67641) and tetrahydrofuran (109999), heavy metals such as lead (7439921) and nickel (7440020), dusts, and a broad range of manufacturing processes have induced hyposmia. Chemicals such as trichloroethylene (79016), chloromethanes, and carbon-monoxide (630080) have been reported to reduce the sensitivity of the trigeminal nerve. Since odor detection can serve as an early warning of exposure, it is recommended that efforts should be made to ensure that workplace chemical exposures do not add to the various causes of hyposmia that may already exist 

11/06/2007