Abstract

Although a number of epidemiological studies have demonstrated the potential ill-effects of occupational exposure to anaesthetic gases, there is currently no Québec exposure limit for these substances. This project was undertaken to determine the extent to which Québec hospital workers are exposed to anaesthetic gases, and to develop simple and effective means to reduce existing exposures. Sampling of anaesthetic gases and vapours was performed in 10 operating rooms in the Montréal area during a variety of surgical procedures, both before and during the administration of the anaesthetic, in order to determine the emission pattern. Nitrous oxide levels were determined by infrared spectrophotometry.

The results of this study indicate that nitrous oxide levels during surgery vary between 25 - 850 ppm, depending on the operating room and the hospital. Leaks are widespread and constitute the primary source of exposure, and the existing ventilation systems appear inadequate for controlling exposure. A complete anaesthetic gas emission control program is presented, entailing a gas recovery system, inspection of leak points, and training of personnel.