Study finds gaps in evidence for air-cleaning technologies designed to prevent respiratory infections

A recent study conducted by researchers from the University of Colorado Anschutz Medical Campus and the National Institute for Occupational Safety and Health (NIOSH) revealed that while many indoor air cleaning technologies claim to prevent the spread of viruses like COVID-19 and the flu, most of them have not undergone testing on humans, and their potential risks are not fully understood.

Published in the Annals of Internal Medicine, the study reviewed nearly 700 research papers spanning from 1929 to 2024 on various air cleaning technologies such as HEPA filters, UV light, ionizers, and advanced ventilation systems. The findings indicated that only 9% of these studies assessed the impact of these technologies on human health outcomes.

Lead researcher Lisa Bero, Ph.D., emphasized the need for more robust studies that evaluate the real-world effectiveness of these technologies in reducing illness transmission rather than just measuring air quality. The study also raised concerns about potential health risks associated with some air cleaning devices, such as the production of harmful byproducts like ozone.

The researchers recommended that consumers opt for air purification systems that have been independently tested in real-world settings and to be cautious of products that may emit harmful substances. They also highlighted the importance of maintaining traditional practices like improving ventilation and regular cleaning to promote indoor air quality.