The Corsi-Rosenthal Foundation UK@CRFoundationUK:
New hospital study: air purifiers cut airborne COVID by 98%.
Rooms with HEPA ventilation had zero virus detected.
Clean air is essential public health infrastructure — not a luxury.
“SARS-CoV-2 airborne detection within different departments of a COVID-19 hospital building and evaluation of air cleaners in air viral load reduction” by Ilias S. Frydas, Marianthi Kermenidou, Maria Karypido, Spyros Karakitsios, and Dimosthenis A. Sarigiannis, April 9, 2025, Journal of Aerosol Science
https://doi.org/10.1016/j.jaerosci.2025.106587
Highlights
- Significant differences were found in air viral load between COVID clinic areas.
- No virus has been detected in the air of ICU and HDU hospital units.
- Air viral load in COVID clinic ranged from 25,9 to 1123,7 copies/m3.
- No correlation between PM1 and PM2.5, and SARS-CoV-2 burden.
- Air cleaner showed an effective reduction of air viral load, reaching 98.1%.
Abstract
The pandemic of COVID-19 has brought in light the necessity for the development of novel detection methods for airborne transmitted pathogens, and the importance of effective clean air measures in hospital departments. In this study, airborne SARS-CoV-2 and particle matter (PM1, PM2.5) detection was performed in different areas of the COVID-19 building at the Ippokrateio University Hospital in Thessaloniki, Greece. More specifically, Sioutas cascade impactors were placed in the ICU (Intensive Care Unit) and HDU (High-Dependency Unit) on the first floor, and at the corridor and rooms at the COVID-19 clinic on the second floor. Furthermore, TECORA air pumps were placed at the building entrance to measure for PM1 and PM2.5. Afterwards, in a COVID room with confirmed air viral load an air cleaner was placed to examine the effect on viral load reduction. Results showed that no viral copies were detected in the air of ICU and HDU departments, in which negative pressure air filtration with HEPA filters is applied. On the contrary, viral load was effectively detected in rooms and corridors of the COVID floor and ranged from 25,9 to 1123,7 copies/m3. PM1 filters showed 77.8% viral positivity, and PM2.5 filters were 38.5% virus positive. Moreover, air viral load in the COVID room with an air cleaner showed a reduction of up to 98.1%.
In conclusion, SARS-CoV-2 was effectively detected in the air of different areas in the COVID building after continuous sampling ranging between 24 h to 7 days, and it was shown how important and effective air cleaners are as first-line measures against pathogen airborne transmission in hospital environments.
@EdRes_LearnEarn:
That’s an impressive finding! HEPA filters are known for capturing tiny particles, but seeing such a dramatic impact on airborne viruses is promising. Could this lead to wider adoption in public spaces and schools for enhanced safety?
@AnnieTehworst:
Good ventilation needs to be mandated by law. It’s the only way compliance will ever happen.
@Bookwor48640897:
It’s the only reason I’ll take off a mask at the dentist. Great HEPA filters in every room.
@RevivalCare:
First dental appointment of the day is also a good additional way to reduce risk.
@SHRStone:
I went to a new dentist for a cleaning, and they had high-end air purifiers. The other dentists’ offices in had long waiting lists because some of their staff were out sick. At some point, air purification will be recognized as a cost-saving device.
@backroads_linda:
should be mandatory in public spaces including movie theatres, public schools, grocery stores, public accessible govt bldgs, airports etc.
@EdRes_LearnEarn:
That’s a promising development! HEPA filters not only tackle COVID *but also improve overall air quality by trapping allergens and pollutants. Integrating them into public spaces could be a game-changer for public health*. Have you considered their potential in schools and offices too?