title: Neurobehavioral effects during exposures to propionic acid--an indicator of chemosensory distraction?
abstract: The chemosensory effects of propionic acid (PA) in humans have not been conclusively studied and there is no established occupational exposure limit (OEL) in Germany. In addition to sensory irritation caused by PA, it was hypothesized that the annoying odor of PA might interfere with the performance results. There were 23 consenting healthy participants (12 female, 11 male) in the group studied. They were exposed for 4 h to PA in concentrations of 0.3, 5 and 10 ppm in a cross-over design. During these exposures, performance was recorded with four cognitive tests measuring response-inhibition, working memory, set-shifting, and divided attention. Odor annoyance, other chemosensory sensations, and acute symptoms were assessed before, during, and after exposure with standardized rating scales. Moderate odor annoyance and weak sensory irritation were reported during 5 and 10 ppm exposure conditions. The different levels of exposure to PA had no impact upon the results of three out of the four behavioral tests. The difficulties of the task were reflected in the results. However in the fourth, which was the response-inhibition task, there was significant increase in the error rates which corresponded to the exposure levels. Results from previous experiments suggested high odor annoyance at the investigated concentrations. Our findings showed that odor annoyance and reported sensory irritations were low. In conclusion, the hypothesis of a distractive effect due to the malodor of PA could not be confirmed. Only in concentrations as high as 10 ppm acute PA exposure affected the response accuracy of one of the four neurobehavioral task. For other more annoying substances, a neurobehavioral effect influenced by an indirect mechanism of resources competition is still conceivable.
authors.affiliation: Leibniz Research Centre for Working Environment and Human Factors, Technical University of Dortmund, Ardeystr. 67, Dortmund 44139, Germany. hey@ifado.de
authors.forename: Kathrin
authors.initials: K
authors.lastname: Hey
authors.forename: Stephanie
authors.initials: S
authors.lastname: Juran
authors.forename: Michael
authors.initials: M
authors.lastname: Schäper
authors.forename: Stefan
authors.initials: S
authors.lastname: Kleinbeck
authors.forename: Ernst
authors.initials: E
authors.lastname: Kiesswetter
authors.forename: Meinolf
authors.initials: M
authors.lastname: Blaszkewicz
authors.forename: Klaus
authors.initials: K
authors.lastname: Golka
authors.forename: Thomas
authors.initials: T
authors.lastname: Brüning
authors.forename: Christoph
authors.initials: C
authors.lastname: van Thriel
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000187:drug effects; D003072:Cognition Disorders / Q000139:chemically induced* / Q000150:complications*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D019570:Inhalation Exposure; D007266:Inhibition, Psychological; D016014:Linear Models; D008297:Male; D008570:Memory, Short-Term / Q000187:drug effects; D009483:Neuropsychological Tests; D000857:Olfaction Disorders / Q000175:diagnosis*; D011422:Propionates / Q000633:toxicity*; D011930:Reaction Time / Q000187:drug effects; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D055815:Young Adult
chemical_list: D011422:Propionates; C029658:propionic acid