EFFECT OF USE OF SURGICAL FACEMASKS AND FFP2 FACEPIECE RESPIRATORS WITH OR WITHOUT EXHALATION VALVES ON BREATHING AIR QUALITY AND PHYSIOLOGICAL OUTCOMES IN HEALTH WORKERS: A QUASI-EXPERIMENTAL MODEL.

After the COVID-19 pandemic, facemasks are widely used and it seems that they will be still with us for a longer time all over the world. There is an ongoing discussion about whether facemasks can be harmful to human health. Therefore, a series of quasi-experimental studies were planned to investigate the effect of masks both on breathing air quality and on physiological outcomes. This second step of the series aimed to investigate the effect of three mask types, commonly used in the community and by healthcare professionals, on breathing air quality, peripheral blood oxygen saturation and heart rate. This study included 30 healthy health workers and compared three types of facemasks: surgical face-masks, FFP2 facepiece respirators with and without exhalation valves. The measurements were made at rest and in room conditions. Oxygen, carbon monoxide, sulphur dioxide, nitrogen oxides, volatile organic compounds concentrations, humidity and temperature were measured in the room area, in the mouth-nose area before the mask was worn and in the same area inside the mask after the mask was worn, while simultaneous blood oxygen concentrations and heart rates were recorded. Significant alterations were observed in in-mask oxygen, volatile organic compounds, humidity and temperature parameters, but never causing inhaled oxygen concentrations to fall below 19.5%, which is the hazardous atmospheric environment oxygen level. The most prominent differences between atmospheric and in-mask values were observed in humidity and temperature (p<0.001). Measured blood oxygen saturations and heart rates were found not to be significantly different between three types of masks, being minimum and maximum values of both within physiological limits. It can be concluded that wearing surgical facemasks, FFP2 facepiece respirators with and without exhalation valves were found not to differ significantly by their physiological effect at rest, but the humidity and temperature in inhaled in-mask air to be above tolerable levels. Working to increase mask comfort can be recommended in order to increase the tolerance to wearing a mask. [ABSTRACT FROM AUTHOR]