HEPA Purifiers and Viral Exposure in Elementary Classrooms
A secondary analysis of a randomized clinical trial found that portable high-efficiency particulate air (HEPA) purifiers were linked to a modest reduction in respiratory virus diversity, but not less viral exposure in elementary classrooms.
The study, published in JAMA Network Open, examined data from the School Inner-City Asthma Intervention Study, conducted in 39 public schools in the Northeast from 2015 to 2020.
- The researchers randomly assigned classrooms to receive either active HEPA purifiers or filterless sham HEPA units.
- Bioaerosol samples were collected three times during the school year and measured levels of 19 respiratory viruses using digital droplet polymerase chain reaction (ddPCR).
No significant reduction in viral exposure was found.
Author's summary: HEPA purifiers reduce virus diversity, not exposure.