An interactive model created by researchers at MIT aims to create a more complex understanding of how safe people are from coronavirus while indoors that takes into account factors beyond how far apart people are.
People stand on the lawn outside Building 10 on the Massachusetts Institute of Technology (MIT) campus in Cambridge, Massachusetts, U.S., on Monday, April 20, 2020. College financial aid offices are bracing for a spike in appeals from students finding that the aid packages they were offered for next year are no longer enough after the coronavirus pandemic cost their parents jobs or income. Photographer: Adam Glanzman/Bloomberg via Getty Images
The researchers, Kasim Khan, John W. M. Bush and Martin Z. Bazant, say that evidence suggests staying at least six feet apart in social settings may not be completely effective in protecting against airborne transmission of coronavirus, especially as time goes by.
Their model calculates “safe exposure times and occupancy levels for indoor spaces” based on a series of other factors, like time, room size, humidity and the behavior of those inside it.
For example, in a restaurant, the model projects that 50 occupants would be safe for two hours, while 100 people would be safe for only 64 minutes. Current general social distancing guidelines suggest 138 people would be safe in the same size of space for an indefinite amount of time, the research notes.
Similarly, the model suggests that two people would be safe for eight days in a church, 25 occupants would be protected for four hours, and 100 people would be safe for only two hours. However, guidelines for merely staying six feet apart indicate 52 people would be safe in that setting for an unlimited period of time.
The model cites a July article in the journal Nature that governments’ advice for the coronavirus hadn’t adapted to new understanding that the virus is airborne.
The U.S. Centers for Disease Control and Prevention have since confirmed that the virus can be spread through aerosols, which “can linger in the air for minutes to hours” and travel farther than six feet.
CDC guidance now notes that the virus can “spread through exposure to those virus-containing respiratory droplets comprised of smaller droplets and particles that can remain suspended in the air over long distances (usually greater than 6 feet) and time (typically hours).”
Asher Klein contributed to this report.