Sensory irritation. Relation to indoor air pollution

Area of Science:

• Neuroscience
• Sensory Physiology
• Environmental Health

Background:

• The body's mucosae possess chemical sensitivity via the common chemical senses (CCS).
• Airborne chemicals stimulate ocular, nasal, and respiratory mucosae, causing pungent sensations like stinging and irritation.
• Pungent sensations differ from odor sensations in concentration thresholds, response to mixtures, and adaptation properties.

Purpose of the Study:

• To explore the characteristics of pungent sensations elicited by airborne chemicals.
• To investigate the potential of reflex apnea as an objective measure of common chemical senses (CCS) function.
• To identify factors influencing common chemical senses (CCS) sensitivity.

Main Methods:

• Stimulation of ocular, nasal, and respiratory mucosae with airborne chemicals.
• Characterization of pungent sensations (e.g., stinging, irritation, burning).
• Measurement of reflex, transitory apnea upon inhalation of pungent chemicals as an objective indicator of CCS function.

Main Results:

• Pungent sensations require higher concentrations than odors but increase more steeply with stimulus concentration.
• Pungency in mixtures shows greater addition than odor sensations and is more resistant to adaptation.
• Higher common chemical senses (CCS) sensitivity was observed in non-smokers, females, and younger adults compared to smokers, males, and the elderly, respectively.

Conclusions:

• Reflex apnea measurement is a promising objective indicator for assessing common chemical senses (CCS) functional status.
• Factors such as smoking status, sex, and age significantly influence common chemical senses (CCS) sensitivity.
• Further research is needed to understand the additivity of pungency in mixtures and the effects of subthreshold chemical exposures.