Occupational exposure and environmental pollution: the role of inhalation anesthetics with special consideration of sevoflurane

Abstract

There are a number of assays available to study genetic toxicity of inhalation anaesthetics. Those discussed in this review are the Ames Salmonella mutagenesis test and assays for structural chromosome aberrations, micronuclei (MN) and sister chromatid exchanges (SCEs). None of these assays showed abnormalities induced by volatile inhalation anaesthetics. Only Compound A induced a slight increase in the number of SCEs. However, the implications of this in vitro study are unclear. Results of studies focussing on the effects of long-term occupational exposure to inhalation anaesthetics are controversial. Neither harmfulness nor safety of chronic exposure to low concentrations of inhalation anaesthetics have been proven. Although there is no clear evidence of harmfulness, there is general agreement that occupational exposure should be minimized for precautionary reasons. This particularly applies to N2O. Therefore, occupational exposure standards have been established in many countries, though not yet for sevoflurane and desflurane. In Germany, occupational exposure can be kept below the threshold values, when working in operation theatres with a standard air conditioning system, a high-flow scavenging system, low leakage anaesthesia machines and preventative maintenance of equipment. Under these conditions occupational exposure is low even when using laryngeal mask airways and uncuffed tracheal tubes. Sevoflurane is a halocarbon, but is only partially halogenated and the only halogen it contains is fluorine. Sevoflurane, therefore, appears to have an insignificant effect on ozone depletion and its contribution to the greenhouse effect is negligible.