Correlation between particulate matter and microbial counts in hospital operating rooms

Abstract

This article presents the findings of an experimental investigation for evaluating correlative relations between particulate matter and microbial concentrations in seven hospital operating rooms. All of the rooms have a positive pressure differential of more than 7 Pa to the adjacent zones. The operating parameters such as air temperature, room pressure, relative humidity and supply air velocity are in compliance with the ISO Class 7 specifications. The PMS Lasair III 310C particle counter was used to measure four different sizes of particulate matter (PM); namely, PM 1, PM 5, PM 10 and PM 25. A MAS-100ECO microbial air sampler was used to measure the microbial counts. The results confirmed that PM 1 and PM 5 do not have an apparent positive correlation with microbial. The amount of PM 1 has no mutual relationship to microbial level. However, on average, PM 5, PM 10 and PM 25 give small correlation percentages to microbial concentration, namely by 5 %, 10 % and 20 %, respectively.