Interindividual differences in chemosensory perception: Toward a better understanding of perceptual ratings during chemical exposures

Perceptions that arise from stimulation of olfactory and trigeminal receptors in the nasal cavity guide the evaluation of chemical environment in humans. Strong interindividual differences in these assessments may be attributed to nonsensory factors such as gender, anxiety, and chemical sensitivity. Knowledge regarding the influence of these factors originates mainly from basic odor research using short-term exposure scenarios. In situations with continuous chemical exposures—common in the working environment—their impact is less clear. To investigate their role during the exposure to workplace chemicals, 4-hour experimental exposure studies (total N = 105) using nine different airborne chemicals were summarized. In each study, subjects evaluated a single chemical in a controlled environment by rating five chemosensory perceptions, including odor intensity, disgust, annoyance, pungency, and burning, several times during occupational limit and low exposures. It was investigated whether the effects of trait-like modulators, such as anxiety and self-reported chemical sensitivity, depend on exposure-related factors and gender. Trait-like modulators markedly affected ratings by women, but not men. Highly anxious women reported more intense annoyance and disgust than less anxious women. Stronger self-reported chemical sensitivity was associated with increased ratings of pungency and burning in women exposed to occupational limit concentrations. This study demonstrates that a complex interplay of exposure-related factors, gender, and trait-like individual differences affects perceptual ratings during continuous chemical exposure. It seems necessary to incorporate the assessment of specific as well as general trait-like modulators into future experimental exposure studies.