More than 288,000 Americans have been killed by a virus that public health officials now say can be spread through airborne transmission.
The virus spreads most commonly through close contact, scientists say. But under certain conditions, people farther than six feet apart can become infected by exposure to tiny droplets and particles exhaled by an infected person, the Centers for Disease Control and Prevention said in October. Those droplets and particles can linger in the air for minutes to hours.
To visually illustrate the risk of airborne transmission in real time, The Washington Post used an infrared camera made by the company FLIR Systems that is capable of detecting exhaled breath.
According to experts, the footage underrepresents the potential risk of exposure from airborne particles. Those particles may spread farther or linger longer than the visible exhalation plume, which dissipates quickly to a level of concentration the camera can no longer detect.
Environmental factors such as airflow in a space, wind and sunlight can reduce the chances of spread, as can such behavioral factors as mask-wearing and social distancing. The risk of exposure increases when people are not wearing masks and are close together in an enclosed space or in an area with poor ventilation.