Non surgical areas of an operating ward pollution by anaesthetic gases, a geostatistical research method.

Background Among the most feared chemical hazards in hospitals, sometimes inappropriately, pollution by anaesthetic gases is considered to be of greater impact on the health of staff in operating rooms. The problem can arise, as usual, on the subjective perceptions and a lack of application of scientific evidence in order to assess the risk of anaesthetic gas in its appropriate size. Much has been said about the operating rooms pollution by anaesthetic gases, while little or nothing is known about the contamination of non-surgical areas of operating ward. The aim of this study is to verify non surgical health staff exposure to anaesthetic gases when performing their job, in order to sample gas concentration in passageways (corridors), technical rooms, instruments storage room, recovery room and ward sister’s room. Methods Sampling was carried out by a photoacoustic spectrophot- ometer with a single point sampling probe positioned 80–100 cm far from the ground to measure gas concentration (sevoflurane and nitrous oxide). We also evaluated environ- mental gas concentration using spatial data modelling techniques, in order to assess anaesthetics diffusion and non surgical areas of operating ward pollution. Geostatistics may be applied to study the behaviour of every kind of variables, their auto and mutual correlations, and by means of a specific software, we obtained different iso-values maps of gas concentration. Results Our results show that nitrous oxide average concentration in passageways is 1.13ppm [95% confidence interval (CI) 1.132171–1.136638], in ward sister’s room average concentra- tion is 1.26ppm (95% CI 1.254324–1.2691478), and in recovery room average concentration is 4.85ppm (95% CI 4.820463–4.897549). Sevoflurane average concentration resulted 0.45ppm in passageways (95% CI 0.449075– 0.461991), 0.41ppm (95% CI 0.409237–0.415332) in ward sister’s room and 1.06ppm (95% CI 1.058889–1.062161) in recovery room. Conclusions These results demonstrate that operating ward health person- nel is subject to a risk from exposure to anaesthetic gases even if their job does not bring them to stay in the operating room.