title: Experimental exposure to methylformate and its neurobehavioral effects.
abstract: OBJECTIVE
  The aim of the study was to investigate the acute effects of experimental methylformate exposure on the nervous system.
  
  
  METHODS
  In an exposure chamber, 20 subjects were exposed to methylformate at 100 ppm [Swiss maximum allowable concentration (MAC)] for 8 h. The same number of subjects with the same ages (between 20 and 30 years), gender and education level (university) were examined by the same procedure as a control group. The subjects did not know if they were exposed or not. Three times (morning, noon, evening) during these 8 h, mood [Profile of Mood States (POMS)], neurobehavioral performance (reaction, Stroop, nonverbal learning, determination, tracking; Wiener Test System), vision (visual acuity, contrast sensitivity, color sensitivity) and postural sway were tested. During an undemanding test (POMS) and a demanding performance task (determination test), pulse, electromyography (EMG) of the forehead and of the neck were recorded. In the morning and evening spirometry [forced vital capacity (FVC), forced one-second expiration volume (FEV), medium expiration flow (MEF) and peak expiration flow (PEF)] and the odor perception threshold were measured.
  
  
  RESULTS
  In the evening, in the exposed group, fatigue was significantly increased and the EMG of the forehead during a demanding task showed a different development during exposure. The other tests showed no significant solvent effect, but 16 of 43 test parameters showed a significant effect of time.
  
  
  CONCLUSIONS
  The results of this study indicate a possible effect of methylformate exposure on the subjective feeling of fatigue after 8 h exposure at 100 ppm in young and healthy subjects, without measurable impairment of neurobehavioral performance. We assume that a similar effect in normal work, combined with a heavy workload and shift work, can lead to an impairment of productivity, and increase the risk of accidents.
authors.affiliation: Institute of Hygiene and Applied Physiology, Zürich, Switzerland. sethre@iha.bepr.ethz.ch
authors.forename: T
authors.initials: T
authors.lastname: Sethre
authors.forename: T
authors.initials: T
authors.lastname: Läubli
authors.forename: M
authors.initials: M
authors.lastname: Berode
authors.forename: M
authors.initials: M
authors.lastname: Hangartner
authors.forename: H
authors.initials: H
authors.lastname: Krueger
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D004576:Electromyography / Q000187:drug effects; D005221:Fatigue / Q000209:etiology*; D005260:Female; D005563:Formic Acid Esters / Q000009:adverse effects*; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects / Q000502:physiology; D009483:Neuropsychological Tests; D016273:Occupational Exposure; D011897:Random Allocation; D013647:Task Performance and Analysis
chemical_list: D005563:Formic Acid Esters; C025468:methyl formate