COVID-19 can be transmitted between people who are standing more than four feet apart, even if they are wearing a mask, a new study has found.
The research, published in Physics of Fluids, notes that face coverings alone do not prevent droplets of fluid that are projected by a cough, a discovery the researchers called "alarming." It adds to the importance to also maintain proper social distancing measures, they said.
The same researchers found previously that droplets of saliva can travel 18 feet in five seconds when an unmasked person coughs, so masks are important. However, repeated coughs are likely to reduce their effectiveness, the experts found in the new study, using computer models.
"The use of a mask will not provide complete protection," study co-author and University of Nicosia professor Dimitris Drikakis said in a statement. "Therefore, social distancing remains essential."
If a person has a coughing fit, "many droplets penetrate the mask shield and some saliva droplet disease-carrier particles can travel more than 1.2 meters (4 feet)," Drikakis added.
The calculations from the simulation also noted that droplet size could be affected due to hitting the mask, escaping and eventually, entering the environment.
"The droplet sizes change and fluctuate continuously during cough cycles as a result of several interactions with the mask and face," Drikakis explained.
"Masks decrease the droplet accumulation during repeated cough cycles," Dr. Talib Dbouk, the study's co-author, added. "However, it remains unclear whether large droplets or small ones are more infectious."
The study's findings have implications for health care workers, who are often unable to maintain proper social distancing.
The researchers suggested wearing "much more complete personal protective equipment," including helmets with built-in air filters, face shields, disposable gowns and two sets of gloves.
Earlier this month, the World Health Organization updated its guidance to recommend that governments around the world encourage the widespread use of fabric face masks while in public settings.
Initially, the WHO advised only those who are experiencing symptoms of COVID-19 or are caring for someone infected with the novel virus to wear a face mask. The WHO’s new recommendations also lag behind those from other top health agencies, such as the Centers for Disease Control and Prevention (CDC).
In April, the CDC updated its guidelines to recommend all Americans wear cloth face coverings while in public, “especially in areas of significant community-based transmission."
As of Tuesday morning, more than 8 million coronavirus cases have been diagnosed worldwide, more than 2.1 million of which are in the U.S., the most impacted country on the planet.