The exact origins of the Centers for Disease Control and Prevention’s six-foot social distancing guideline are unclear, according to Lindsey Marr, an expert on viral transmission and professor at Virginia Tech.
“It’s almost like it was pulled out of thin air,” Marr told the New York Times.
Marr speculated that at the beginning of the pandemic in March 2020, the CDC may have formulated its guidelines based on the conclusion that the novel coronavirus spread primarily through respiratory droplets, which usually do not travel further than six feet.
However, since that time researchers have found that coronavirus spreads primarily through tiny droplets called aerosols, which can travel over longer distances.
The six-foot guideline is being reviewed by the CDC amid a push to reopen schools across the U.S., many of which cannot open effectively while keeping all students six feet apart. Studies in Massachusetts and Wisconsin have indicated that children and teachers can return to classrooms with social distancing at as little as three feet, as long as other mitigation strategies, such as universal mask-wearing and good ventilation, are put in place.
“Provided we have universal masking mandates, I think it’s very reasonable to move to a three-foot recommendation,” Dr. Westyn Branch-Elliman, a specialist in infectious diseases at the VA Boston Healthcare System, told the Times.
The Massachusetts and Wisconsin studies also indicated that coronavirus transmission in schools with mask-wearing, good ventilation, and some social distancing, remained minimal even when transmission in the surrounding communities was relatively high.
A California judge on Monday blocked the state from enforcing “arbitrary” school reopening guidelines in response to a law suit filed by the Parent Association of North County San Diego. The judge, Cynthia Freeland, wrote that the state’s reopening document, which including the requirement that students remain four feet from each other, was “selective in its applicability, vague in its terms, and arbitrary in its prescriptions.”
Dr. Anthony Fauci, the nation’s top infectious disease expert, acknowledged Sunday that the CDC is “very well aware that data are accumulating making it look more like three feet are okay under certain circumstances.”