Research has revealed that reducing capacity does not cut the risk of catching Covid in well-ventilated indoor spaces
Professors Martin Bazant and John Bush from the world renowned Massachusetts Institute of Technology (MIT) say the ‘six foot rule’ that encourages people to socially distance in public has no solid basis in science.
They explained that the risk of being exposed to the coronavirus indoors is the same whether people are six feet or 60 feet apart, and that this risk is low in well-ventilated spaces.
Bazant and Bush developed a model to calculate indoor exposure risk based on time spent inside, air filtration and circulation, immunizations, respiratory activity, variants and mask use.
The guideline they developed suggests a limit for exposure time, based on the number of people, the size of the space, the kinds of activity, whether masks are worn, and the ventilation and filtration rates.
Opening windows or installing new fans to keep the air moving could be just as effective or more effective than spending large sums of money on a new filtration system, said Professor Bazant.
“Our analysis also shows that many rooms that have actually been closed do not have to be closed. Often the room is big enough, the ventilation is good enough, the time people spend together is so big rooms can be even at full capacity safely operated, and the scientific support for reduced capacity in these rooms is really not very good, “explained Bazant. “I think if you enter the numbers, even now, for many types of rooms, you will find that no occupancy restrictions are required.”
“We argue there really isn’t much of a benefit to the 6-foot rule, especially when people are wearing masks,” Bazant said in an interview with CNBC. “It really has no physical basis because the air a person is breathing while wearing a mask tends to rise and comes down elsewhere in the room so you’re more exposed to the average background than you are to a person at a distance.”
Bazant said that guidelines enforcing indoor occupancy limits are flawed and the important variable the CDC and the WHO have overlooked is the amount of time spent indoors.
“What our analysis continues to show is that many spaces that have been shut down in fact don’t need to be,” Professor Bazant told CNBC.
As for outdoor social distancing, Professor Bazant says it makes practically no sense and that outdoor social distancing with masks on is “kind of crazy.”
“When you look at the flow of air outside, the infected air is swept away and is very unlikely to cause transmission. There are very few recorded cases of outdoor transmission.” he said. “Crowded outdoor spaces could be a problem, but if people keep a reasonable distance of about three feet outside, I feel pretty comfortable with it even without masks.