title: Neuropsychological impairment from acute low-level exposure to carbon monoxide.
abstract: OBJECTIVE
  To investigate the effects of acute low-level exposure to carbon monoxide on higher cognitive functions in healthy humans.
  
  
  METHODS
  An empirical study of the effects of low-level exposure to carbon monoxide on higher cognitive functions in young healthy volunteers and a matched nonexposed control group.
  
  
  METHODS
  A dormitory at the Hebrew University campus in Jerusalem, Israel.
  
  
  METHODS
  Forty-five student volunteers who were exposed to carbon monoxide from residential kerosene stoves for 1.5 to 2.5 hours (air carbon monoxide concentrations of 17-100 ppm; mean +/- SD, 61 +/- 24 ppm) served as the experimental group and 47 nonexposed students served as the control group.
  
  
  METHODS
  A battery of neuropsychological tests was administered to each participant including digit span, the revised Wechsler Memory Scale for verbal and figural memory, Trail-Making Test parts A and B, digit symbol, block design, and the Rey Auditory Verbal Learning Test.
  
  
  RESULTS
  Venous blood carboxyhemoglobin (Hbco) levels in participants of the study group ranged from 0.01 to 0.11 (mean +/- SD, 0.04 +/- 0.03) and correlated with air carbon monoxide concentrations (r = 0.39; P = .01). The experimental group scored significantly lower than controls on the following tests: digit span forward (P = .02), short-term (P = .008) and long-term semantic memory (P = .008), digit symbol (P = .004), block design (P = .009), recall of figural memory (P = .02), and Trail-Making part A (P = .04). No significant differences were found between the experimental and control groups in other tests.
  
  
  CONCLUSIONS
  The lower scores on neuropsychological tests indicate dysfunctions in memory, new learning ability, attention and concentration, tracking skills, visuomotor skills, abstract thinking, and visuospatial planing and processing. These dysfunctions correspond with previous reports of carbon monoxide neurotoxic effects in patients with moderate carbon monoxide poisoning. Low-level exposure to carbon monoxide results in impairment of higher cognitive functions. Neuropsychological testing appears to be sensitive in the detection of subtle neurologic dysfunctions resulting from carbon monoxide poisoning.
authors.affiliation: Department of Pediatrics, Hadassah University Mt Scopus, Jerusalem, Israel.
authors.forename: Y
authors.initials: Y
authors.lastname: Amitai
authors.forename: Z
authors.initials: Z
authors.lastname: Zlotogorski
authors.forename: V
authors.initials: V
authors.lastname: Golan-Katzav
authors.forename: A
authors.initials: A
authors.lastname: Wexler
authors.forename: D
authors.initials: D
authors.lastname: Gross
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor; D002248:Carbon Monoxide / Q000009:adverse effects*; D003071:Cognition / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D007858:Learning / Q000187:drug effects*; D008297:Male; D008568:Memory / Q000187:drug effects*; D009483:Neuropsychological Tests
chemical_list: D002248:Carbon Monoxide