The influence of health-risk perception and distress on reactions to low-level chemical exposure

Abstract

The general aim of the current study was to investigate how perceived health risk of a chemical exposure and self-reported distress are related to perceived odor intensity and odor valence, symptoms, cognitive performance over time as well as reactions to blank exposure. Based on ratings of general distress, 20 participants constituted a relatively low distress group, and 20 other participants a relatively high distress group. Health risk perception was manipulated by providing positively and negatively biased information regarding n-butanol. Participants made repeated ratings of intensity, valence and symptoms and performed cognitive tasks while exposed to 4.7 ppm n-butanol for 60 min (first 10 min were blank exposure) inside an exposure chamber. Ratings by the positive and negative bias groups suggest that the manipulation influenced perceived health risk of the exposure. The high distress group did not habituate to the exposure in terms of intensity when receiving negative information, but did so when receiving positive information. The high distress group, compared with the low distress group, rated the exposure as significantly more unpleasant, reported greater symptoms and performed worse on a cognitively demanding task over time. The positive bias group and high distress group rated blank exposure as more intense. The main findings suggest that relatively distressed individuals are negatively affected by exposures to a greater degree than non-distressed.

Keywords: bias; cognition; distress; environmental psychology; health-risk perception; olfaction; perception; sensitization.

Figure 1

Overview of experimental procedure. The exposure session began at min 0.

Figure 2

Mean (+ standard error) ratings of harmful or beneficial health effects of the chemical exposure, using a Borg CR-100 scale. P-values refer to the ANOVA parameter estimates (^*p < 0.05).

Figure 3

Mean (± standard error) ratings of intensity and valence in 5 min intervals, using a Borg CR-100 scale. Pleasantness was rated as positive values and unpleasantness as negative values. Shaded areas indicate values used in the statistical analyses. The first two ratings were made during blank exposure. The last nine ratings were made when the n-butanol concentration was at a stable concentration. P-values refer to the ANOVA parameter estimates (^*p < 0.05, ^**p < 0.01, ^***p < 0.001).

Figure 4

Mean (+ standard error) ratings of eye irritation, nose irritation, skin irritation, throat irritation, shortness of breath, concentration difficulties, dizziness, tiredness, headache, and nausea before (pre), in the middle of (mid) and at the end of the n-butanol exposure session. Ratings are made on a Borg CR-100 scale. P-values refer to the ANOVA parameter estimates (^**p < 0.01).

Figure 5

Mean (+ standard error) number of correctly recalled sequences in the updating task. P-values refer to the ANOVA parameter estimates.