Air filtration systems do not reduce the risk of viral infection, according to a new study from the University of East Anglia
Increasing pollution and the COVID-19 pandemic have brought into fashion air purifiers, devices that promise to clean the air in the home of pollution, but also of viruses and bacteria. A new study published today shows that current room cleaner technologies are not effective in practice.
Researchers examined technologies such as air filtration, germicidal lights and ionizers. They examined all available data but found little evidence to support the hope that these technologies could make the air safer from respiratory or gastrointestinal infections.
“Air purifiers are designed to filter pollutants from the air that passes through them. When the Covid pandemic broke out, many large companies and governments – including the NHS, the British Army and the governments of New York and German regions – investigated installing this type of technology to reduce virus particles in the air from buildings and small ones places.
Professor Paul Hunter from UEA Norwich Medical School, one of the study’s authors, said: “Air treatment technologies can be expensive.” Therefore, it makes sense to weigh the benefits against the costs and understand the current capabilities of such technologies.
The research team examined the evidence on whether air purification technologies protect people from respiratory or gastrointestinal infections that are transmitted through the air. They analyzed the evidence on microbial infections or symptoms in people who were or were not exposed to air treatment technologies in 32 studies, all conducted in real-world settings such as schools or nursing homes. To date, none of the air treatment studies initiated during the Covid era have been published.
The lead researcher Dr. Julii Brainard, also from UEA Norwich Medical School, said: “The types of technologies we looked at included filtering, germicidal lights, ionizers and any other way to safely kill viruses or deactivate them in the air we breathe.” In short, we have found no clear evidence that air treatment technologies can protect people in the real world.”
There is considerable evidence that air and surface pollution can be reduced through various air treatment strategies, particularly germicidal lamps and high-efficiency particulate air filtration (HEPA). However, combined tests showed that these technologies cannot stop or reduce the disease.
According to Brainard, “There was some weak evidence that air treatment methods reduced the likelihood of infection, but this evidence appears to be biased and unbalanced.” We strongly suspect that there were some relevant studies with little or no effect, but they were never published . “Our results are disappointing, but it is important that health authorities have a complete picture.”
Effectiveness of filtering or decontamination of air to reduce or prevent respiratory infections: A systematic review