Pollution of work areas by volatile anaesthetics and nitrous oxide occurs during general anaesthesia. Short anaesthesia procedures are often carried out in operating theatres that are not equipped with air-conditioning systems. Methods of lowering exposure during short procedures, where mask anaesthesia is the usual procedure, are double masks and the laryngeal mask. The aim of our investigation was to determine the possibility of lowering the pollution of the environment to below national and international thresholds in a non-air-conditioned work area and to find out which method of anaesthesia is the most effective in environmental protection, i.e. which has the lowest leakage rate. METHODS In our investigation, at two points of the work area the mean enflurane [2-chloro-1-(difluor-omethoxy)-1,1,2-trifluoro-ethane] concentrations were measured under daily routine conditions in a non-ventilated anaesthesiological work area by a gas chromatography. Anaesthesia with single masks, double masks, laryngeal masks or endotracheal intubation was carried out. RESULTS No differences were found in the mean concentration of enflurane during the anaesthesia procedures. The leakage rates of endotracheal intubation anaesthesia were the lowest. CONCLUSIONS In unventilated work areas, it was not possible to lower the exposure of the personnel by changing the method of anaesthesia. The application of procedures like double or laryngeal masks does not avoid the need for installation of air-conditioning systems in all work areas were anaesthesia is performed.