The researchers found that masks cut the distance that airborne pathogens can travel when speaking or coughing, by more than half compared with not wearing a mask.
This finding is important because airborne viral pathogens, such as SARS-CoV-2, can be enveloped and transmitted through liquid droplets and aerosols that are formed during respiratory functions in humans. humans like talking and coughing.
Knowing ways to reduce this transmission gap can help keep people safe and aid in managing responses to pandemics, such as COVD-19, which have led to large-scale infections. demand, overloading the health care system, and economic damage.
These responses may include relaxing some of the social distancing guidelines while wearing a mask.
Study co-author Kareem Ahmed, associate professor in UCF’s department of mechanical and aerospace engineering, said: “The study provides clear evidence and guidance that seeing as far as 3 meters away with a good face covering than 6 meters away without a face covering.
Using diagnostic tools commonly used to understand how liquids move through the air, the researchers measured the distances in all directions that droplets and aerosols travel from speakers and coughs, when wear different types of masks and when not.
Fourteen study participants, 11 men and 3 women, ranged in age from 21 to 31.
Each participant recited a phrase and simulated a cough for 5 minutes without covering their face, covering their face with a cloth, and wearing a disposable three-layer surgical mask.
Planar particle imaging is used to measure particle velocities; a phase Doppler interferometer used to measure droplet size, velocity and volumetric flux at points in a nebulizer; and an aerodynamic particle smoother were used to determine the behavior of airborne particles.
The devices measure the characteristics, behavior and direction of airborne particles as they move outward from the participants’ mouths.
The researchers found that a face covering reduced emissions in all directions by about 2 feet compared with 4 feet of emissions produced when coughing or speaking without a mask on.
The reduction is even greater when wearing a surgical mask, which reduces the emission distance of coughing and speaking to only about half a foot.
The researchers got the idea for this study from their jet engine research.
“The principles are the same,” says Ahmed. “Our coughs and our words are exhausting thrusters.”
This study is part of a larger overall effort by researchers to control airborne disease transmission, including through food ingredients, to better understand the factors involved. becoming a super-spreader; and modeling airborne disease transmission in the classroom.
Next, the researchers will expand the study to include more participants. The work was funded in part by the National Science Foundation.