Most air purifiers have not been tested on humans. It’s a problem

Portable air cleaners aimed at slowing down the infections’ infections are rarely tested for the way they protect people – and very few studies assess their potentially harmful effects. It is the result of a detailed review of nearly 700 studies that we have co-written in the journal Annals of Internal Medicine.

Many respiratory viruses, such as COVID-19 and Fluenza, can spread in indoor air. Technologies such as HEPA filters, ultraviolet light and special ventilation conceptions – known collectively under the name of engineering infection controls – are intended to clean indoor air and prevent viruses and other pathogenic pathogens of the disease.

In addition to our colleagues in three university establishments and two government scientific agencies, we have identified and analyzed each research study evaluating the effectiveness of these published technologies from the 1920s to 2023-672 of them in total.

These studies have evaluated performance in three main ways: some have measured if the interventions have reduced infections in people; Others have used animals such as guinea pigs or mice; And the rest has taken air samples to determine whether the devices reduced the number of small particles or microbes in the air. Only around 8% of studies have tested the effectiveness of people, while more than 90% tested the devices in unoccupied spaces.

We have found a substantial variation between different technologies. For example, 44 studies have examined an air cleaning process called photocatalytic oxidation, which produces chemicals that kill microbes, but only one of those that have been tested if technology has prevented infections in people. 35 Other studies have evaluated plasma technologies to kill microbes, and none involved human participants. We also found 43 studies on filters incorporating nanomaterials designed to capture and kill microbes – again and again, none of the human tests.

Why it matters

The COVVI-19 pandemic has shown how disruptive airborne infections can be: the cost of millions of lives around the world, health systems and the closing of schools and workplaces. The first studies have shown that the COVVI-19 virus spread in the air. Logically, improving indoor air quality to erase the air virus has become a major objective as a way to protect people.

Finding effective ways to withdraw microbes from indoor air could have profound public health benefits and could help limit economic damage to future pandemics. Controls of engineering infections could protect people from infections by working in the context of daily life, without any effort on the part of people.

Companies producing portable air cleaners that incorporate microbes killers technologies have made ambitious affirmations on the efficiency of their air purification and prevent infections. These products are already marketed with consumers for use in daycares, schools, health care clinics and workplaces. We found that most of them have not been properly tested for efficiency. Without solid evidence of studies on people, it is impossible to know if these promises correspond to reality. Our results suggest that consumers should be cautious when investing in air cleaning devices.

The gap between marketing claims and effectiveness evidence may not be surprising, but there is more at stake here. Some of these technologies generate chemicals such as ozone, formaldehyde and hydroxyl radicals to kill microbes – substances that can potentially harm people if they are inhaled. The safety of these products should be the reference requirement before being widely deployed. However, of the 112 studies evaluating many of these pathogenic killers technologies, only 14 have tested harmful by-products. This is a striking contrast with pharmaceutical research, where safety tests are standard practices.

Which is still not known

More than 90% of all studies have tested these technologies by looking at the air itself – for example, by measuring the way in which experimental gases, dust particles or microbes have been eliminated from the air. The idea is that the cleaner air should mean lower chances of infection. But with regard to air cleaning, researchers do not yet know how these air measures reflect the real reduction of infections for people.

The identification of the safest and most effective options will require assessing these technologies for toxic by-products and to assess them in real contexts that include people. In addition, the standardization of potential efficiency and damage will help to shed light on evidence based on evidence regarding the improvement of air quality in houses, schools, health establishments and other interior spaces.

The research thesis is a short interpretation of interesting academic work. Amiran Baduashvili, Associate Professor of Medicine, University of Colorado Anschutz Medical Campus and Lisa Bero, professor of medicine and public health, University of Colorado Anschutz Medical Campus. This article is republished from the conversation under a Creative Commons license. Read the original article.