Mitigating airborne transmission of the coronavirus “should be at the front of our disease-control strategies for COVID-19,” according to Joseph Allen, assistant professor of exposure assessment science at Harvard T.H. Chan School of Public Health.
That’s because evidence suggests that airborne transmission—caused by small particles that can linger in the air for extended periods of time—is responsible for much of the spread of the virus, wrote Allen in a May 26, 2020 opinion piece in the Washington Post.
Much of the information from health officials about how the coronavirus spreads has focused on large droplets from coughing and sneezes and on contaminated surfaces. But evidence suggests that asymptomatic transmission is occurring, which means that people are spreading the virus without coughing or sneezing large droplets, according to Allen. “And basic aerosol physics shows that people shed an entire continuum of particles when they cough, sneeze or talk, including large particles that settle out quickly and smaller ones that stay afloat for hours,” he wrote.
To minimize exposure to these airborne pathogens—especially indoors—Allen recommended continuing to main physical distancing. “Six feet is good, but 10 feet is better,” he wrote. He also advised implementing healthy building strategies, including opening windows in homes and cars, increasing the outdoor air ventilation rate in buildings with HVAC systems, and ensuring enough exhaust in places such as bathrooms and hospital rooms with infected patients.
Read the Washington Post op-ed: We cannot keep ignoring the possibility of airborne transmission. Here’s how to address it.