Portable Air Cleaners Failing to Deliver on Claims to Fight Indoor Infections

Strategic Insights -

The COVID-19 pandemic highlighted the importance of improving indoor air quality to prevent the spread of airborne infections. However, a review of nearly 700 studies on portable air cleaners reveals that many of these devices have been poorly tested for their effectiveness in reducing infections in people. Furthermore, most studies have not evaluated the potentially harmful effects of these technologies, which can generate chemicals that can harm humans when inhaled.

Key Takeaways:

  • Of the 672 studies analyzed, only about 8% tested the effectiveness of portable air cleaners on human participants, while over 90% tested the devices in unoccupied spaces.
  • Substantial variation was found across different technologies, with some air cleaning processes, such as photocatalytic oxidation, being tested in only one study that involved human participants.
  • None of the 43 studies on filters incorporating nanomaterials designed to capture and kill microbes included human testing.
  • Companies producing portable air cleaners have made ambitious claims about their ability to purify air and prevent infections, but most of these claims have not been supported by solid evidence from studies on people.
  • Only 14 out of 112 studies assessing pathogen-killing technologies tested for harmful byproducts, highlighting the lack of safety testing in this field.

Statistics:

  • 672 studies were analyzed in total, covering research published from the 1920s through 2023.
  • 8% of studies (53 studies) tested the effectiveness of portable air cleaners on human participants.
  • 90% of studies (604 studies) tested the devices in unoccupied spaces.
  • 44 studies examined photocatalytic oxidation, but only one tested whether the technology prevented infections in people.
  • 35 studies evaluated plasma-based technologies for killing microbes, but none involved human participants.
  • 43 studies evaluated filters incorporating nanomaterials, but none included human testing.
  • 112 studies assessed pathogen-killing technologies, but only 14 tested for harmful byproducts.

Sources:

  • Amiran Baduashvili, Lisa Bero, et al. (2023). "Engineering Infection Controls to Prevent Viral and Other Microbial Spread in Indoor Environments," Annals of Internal Medicine.
  • University of Colorado Anschutz Medical Campus.
  • AllAfrica Global Media (allAfrica.com).