Facemasks halve the distance airborne pathogens travel

Viral airborne pathogens like COVID-19 are easily transmitted through respiratory emissions. Containing the spread of these infections is critical to pandemic response and management and helps safeguard healthcare infrastructure and reduce economic fallout. A new study indicates that when worn correctly, face masks are highly effective in preventing the transmission of airborne diseases and could allow for the use of reduced social distancing measures.

A U.S. National Science Foundation grant allowed researchers at the University of Central Florida to conduct a study on the efficacy of face masks in preventing the spread of airborne diseases. The scientists found that face masks reduce the distance airborne pathogens can travel from direct exposure when speaking or coughing by more than half, compared to not wearing a mask. The results are published in The Journal of Infectious Diseases.

Study participants recited a phrase and simulated coughing for five minutes with no face covering, a cloth face covering, and a three-layered disposable surgical mask. The researchers then measured particle velocity, direction, droplet size and volume of airborne particles. The data demonstrate that when wearing no face covering, emissions traveled about 4 feet, a cloth face covering reduced emissions to 2 feet, and a surgical mask limited emissions to close to 6 inches.

"The research provides clear evidence and guidelines that 3 feet of distancing with face coverings is better than 6 feet of distancing without face coverings," said co-author of the study Kareem Ahmed.