Faulty anesthesia circuits: a source of environmental pollution in the operating room.

Commonly used disposable anesthesia circuits were studied for leak and gas spillage. Trace anesthetic gas concentrations produced by these circuits in the anesthesiologist's breathing zone were analyzed by a Hewlett-Packard Gas Chromatograph. These measurements demonstrated ambient halothane (3.29 +/- 0.1 ppm) and N2O (333.5 +/- 2.31 ppm) concentrations well above target levels, when swivel-type disposable anesthesia circuits were used, despite the presence of standard gas-scavenging devices and appropriate operating room fresh air exchange rates. Lower ambient concentration levels (0.38 +/- 0.03 ppm halothane and 31.3 +/- 1.49 ppm N2O) were measured when Y-type disposable anesthesia circuits were used.