Acute exposure to 50ppm toluene does not increase sleepiness.

Area of Science:

• Neuroscience
• Occupational Health
• Toxicology

Background:

• The Pupillographic Sleepiness Test (PST) is a novel neurophysiological tool for assessing sleepiness.
• Occupational exposure to toluene can potentially impact cognitive functions and induce sleepiness.

Purpose of the Study:

• To evaluate the efficacy of the PST in detecting increased sleepiness following acute exposure to toluene.
• To assess the effects of 50ppm toluene exposure on subjective complaints using the Swedish Performance Evaluation System (SPES).

Main Methods:

• A controlled exposure study involving 20 healthy men exposed to 50ppm toluene for 4.5 hours.
• Pupillographic Sleepiness Test (PST) administered before and after toluene exposure.
• Swedish Performance Evaluation System (SPES) questionnaire used for self-assessment of general complaints.

Main Results:

• Parametric analysis of Pupillary Unrest Index (PUI) values showed no significant effect of toluene exposure.
• Nonparametric analysis of SPES scores revealed increased reports of unpleasant smell and throat irritation, but not tiredness.
• The Pupillographic Sleepiness Test (PST) did not detect increased sleepiness.

Conclusions:

• Acute exposure to 50ppm toluene, at the German threshold limit value, did not induce measurable sleepiness using the PST.
• While toluene exposure caused sensory irritation, it did not lead to increased subjective sleepiness in this study.
• The PST may not be sensitive to subtle changes in sleepiness induced by moderate toluene exposure.