Does odour cross contamination alter olfactory thresholds in certain odours?

Area of Science:

• Olfactory psychophysics
• Sensory science
• Neuroscience

Background:

• Assessing olfactory function requires reliable odorant threshold measurements.
• Potential odorant cross-contamination or adaptation effects can impact test accuracy.
• Standardized testing protocols are crucial for valid olfactory assessments.

Purpose of the Study:

• To investigate cross-contamination between different odorants during olfactory threshold testing.
• To determine if a delay period is necessary between testing various odorants.
• To evaluate the impact of high odorant concentration exposure on subsequent threshold measurements.

Main Methods:

• Thirty-five subjects underwent olfactory threshold testing using serial logarithmic dilutions for phenethyl alcohol (PEA), ethylmercaptan (MER), acetic acid (ACE), and eucalyptol (EUC).
• Subjects were exposed to high concentrations of PEA, ACE, and EUC on separate occasions.
• Olfactory thresholds for all four odorants were re-tested post-exposure, and pre- and post-exposure thresholds were compared.

Main Results:

• Exposure to high concentrations of PEA, ACE, and EUC did not significantly alter olfactory thresholds for other odorants.
• Minor cross-contamination effects were observed specifically with acetic acid (ACE) and eucalyptol (EUC) under certain conditions.
• The magnitude of threshold alteration was generally small, within 10-2.

Conclusions:

• Limited cross-contamination occurs between ACE and EUC, necessitating careful consideration of odorant presentation order.
• A specific odorant sequence (PEA, MER, ACE, EUC) is recommended to minimize cross-contamination effects.
• The odorants PEA, MER, ACE, and EUC are suitable for olfactory testing when presented in the recommended order.