Formaldehyde: environmental contamination in the operating wards.

Background In hospitals, formaldehyde is mainly used in higher concentration solutions to fix tissues and to preserve anatomical parts. The IARC, in 2004, has classified formaldehyde in Group 1 of carcinogens, carcinogenic to humans. However,formaldehyde is still irreplaceable for some sanitary uses in operation wards. Methods In this study, we evaluated the diffusion of formaldehyde in a few operating rooms, using geostatistical spatial data modelling techniques to identify sources, variability and distribution of air pollutants, in order to assess hospital staff exposure. For modelling formaldehyde diffusion, indoor air samplings were carried out in 22 operating rooms of two different surgical wards A and B in a hospital in Rome, by a transportable photoacoustic spectrometer ‘Multi-gas monitor’ with apposite software. Each measurement was performed throughout 22 surgical sessions. In the operating wards, two series of samplings were carried out: the first one during each surgical session in one sampling site near the anaesthetic machine; and the other one measuring formalde- hyde concentration in 20 different sampling sites of the ‘A’ operating ward and 22 of the ‘B’ one. The probes were placed at about 130 cm above ground. Results In the first step, we detected different average concentrations of formaldehyde in surgical wards ‘A’ and ‘B’, 0.067ppm (95% CI 0.066–0.067), max 0.14ppm, and 0.201 ppm (95% CI 0.199–0.204) max 0.46ppm, respectively. In 16 operating rooms, we found concentrations that exceed the TLV-STEL Ceiling (0.30ppm), although in the operating rooms for- maldehyde should not be used at all. We carried out the second step of monitoring in order to create geostatistical spatial data maps to identify the contamination sources. Conclusions Linear geostatistical 2D and 3D iso-value maps of the Formaldehyde expected values show an evident contamination in formaldehyde storage site and in fixing tissues and anatomical parts area.