title: Nitrous oxide levels in operating and recovery rooms of Iranian hospitals.
abstract: BACKGROUND
  Nitrous oxide (N(2)O) is the oldest anesthetic in routine clinical use and its occupational exposure is under regulation by many countries. As studies are lacking to demonstrate the status of nitrous oxide levels in operating and recovery rooms of Iranian hospitals, we aimed to study its level in teaching hospitals of Tehran University of Medical Sciences.
  
  
  METHODS
  During a 6-month period, we have measured the shift-long time weighted average concentration of N(2)O in 43 operating and 12 recovery rooms of teaching hospitals of Tehran University of Medical Sciences.
  
  
  RESULTS
  The results show that the level of nitrous oxide in all hospitals is higher than the limits set by different countries and anesthetists are at higher risk of exposure. In addition, it was shown that installation of air ventilation could reduce not only the overall exposure level, but also the level of exposure of anesthetists in comparison with other personnel.
  
  
  CONCLUSIONS
  The high nitrous oxide level in Iranian hospitals necessitates improvement of waste gas evacuation systems and regular monitoring to bring the concentration of this gas into the safe level.
authors.affiliation: Dept. of Anesthetics, Faculty of Allied Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Sh Sadigh
authors.initials: ShS
authors.lastname: Maroufi
authors.forename: Mj
authors.initials: M
authors.lastname: Gharavi
authors.forename: M
authors.initials: M
authors.lastname: Behnam
authors.forename: A
authors.initials: A
authors.lastname: Samadikuchaksaraei
keywords: Environmental monitoring; Iran; Nitrous oxide occupational health; Ventilation