Abstract
OBJECTIVE: Airborne particles are one of the most important factors in the spread of infectious pathogens and must be monitored in healthcare facilities. Viable particles are living microorganisms, whereas non-viable particles do not contain microorganisms but act as transport for viable particles. The effectiveness of ozone in reducing these particles in a non-controlled room and a controlled cleanroom using high-efficiency particles air (HEPA) filter was analyzed in this study. MATERIALS AND METHODS: Viable particles and non-viable particles sized 0.5 and 5 μm were quantified before and after ozonation in two different health environments: non-controlled (group 1) and controlled area, which was associated with a HEPA filtering system (group 2). Active air sampling using a MAS 100 was used to count the number of viable particles, while the number of non-viable particles/m(3) was obtained following the manufacturer's recommendations of the Lasair III 310C system. RESULTS: Our results of the viable particles counting were not quantifiable and analyzed using statistical tests. Both groups showed a slight tendency to reduce the number of viable particles after ozonation of the environmental air. A statistically significant reduction of non-viable 5 μm particles after ozonation was observed in both groups (G1: p = 0,009; G2: p = 0,002). Reduction in the non-viable 0.5 μm particles after ozonation was observed only in group 2, associated with the HEPA filter. In group 1, after ozonation, a significant increase in 0.5 μm particles was observed, probably due to the breaking of 5 μm particles by ozone gas. Our results suggest that ozone gas can break 5 μm particles and, when associated with a HEPA filter, increases its effectiveness in removing 0.5 μm particles. CONCLUSION: Considering that 5 μm particles are important in the air transport of microorganisms, their reduction in the environment can be a relevant parameter in controlling the dissemination of infections.