Indoor environments play a significant role in people's health as they spend about 90% of their time indoors. Addressing this global public health issue requires a clear understanding of the transmission process of infections and the implementation of targeted infection prevention and control measures.
Outbreaks of severe acute respiratory syndrome (SARS) and other viral pathogens have had a significant impact on human health and increased public concern about the spread of viral diseases. The global pandemic caused by the novel coronavirus SARS-CoV-2, resulting in the disease known as COVID-19, has profoundly changed the world in unimaginable ways. There is still much to learn about this evolving global threat. However, certain aspects of the virus are known, such as its primary mode of transmission through the air. Therefore, efforts are being made to mitigate the risks faced by the general population through the use of engineering control measures, such as improved air filtration.
Particles with a diameter of 10 micrometers or smaller (≤ PM10) can penetrate and remain in the lungs, while particles with a diameter of 2.5 micrometers or smaller (PM2.5) can penetrate deep into the lungs. Particles smaller than 0.5 micrometers can pass through the blood-gas barrier and enter the bloodstream. Prolonged exposure to particles increases the risk of cardiovascular and respiratory diseases, as well as lung cancer.
Research from reputable institutions consistently shows that capturing airborne microorganisms is not independent of filter efficiency. Assuming particles enter the air handling system, filters serve as effective tools for removing any type of airborne microbial transmission. If a filter can remove non-viable transport particles, it will also remove equally sized viable particles. Adopting higher-grade filters as an engineering control measure can effectively reduce the transmission of airborne viruses, such as the coronavirus.
