title: Sensory and cognitive effects of acute exposure to hydrogen sulfide.
abstract: BACKGROUND
  Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S).
  
  
  OBJECTIVE
  We hypothesized a dose-response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures.
  
  
  METHODS
  In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (+/- SD) = 24.7 +/- 4.2; mean years of education = 16.5 +/- 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period.
  
  
  RESULTS
  Dose-response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose-response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition.
  
  
  CONCLUSIONS
  Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures.
authors.affiliation: Department of Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, 170 Frelinghuysen Rd., Rm. 210, Piscataway, NJ 08854 USA.. nfiedler@eohsi.rutgers.edu <nfiedler@eohsi.rutgers.edu>
authors.forename: Nancy
authors.initials: N
authors.lastname: Fiedler
authors.forename: Howard
authors.initials: H
authors.lastname: Kipen
authors.forename: Pamela
authors.initials: P
authors.lastname: Ohman-Strickland
authors.forename: Junfeng
authors.initials: J
authors.lastname: Zhang
authors.forename: Clifford
authors.initials: C
authors.lastname: Weisel
authors.forename: Robert
authors.initials: R
authors.lastname: Laumbach
authors.forename: Kathie
authors.initials: K
authors.lastname: Kelly-McNeil
authors.forename: Kelechi
authors.initials: K
authors.lastname: Olejeme
authors.forename: Paul
authors.initials: P
authors.lastname: Lioy
mesh_terms: D000328:Adult; D003071:Cognition / Q000187:drug effects; D005260:Female; D006801:Humans; D006862:Hydrogen Sulfide / Q000633:toxicity*; D019570:Inhalation Exposure / Q000009:adverse effects*; D007509:Irritants / Q000633:toxicity*; D008297:Male; D009812:Odorants; D011187:Posture; D011597:Psychomotor Performance / Q000187:drug effects; D011930:Reaction Time / Q000187:drug effects; D014706:Verbal Learning / Q000187:drug effects*; D014792:Visual Acuity / Q000187:drug effects
chemical_list: D007509:Irritants; D006862:Hydrogen Sulfide