Onderzoek MIT: binnen afstand houden is meestal onzinnig

MIT researchers say time spent indoors increases risk of Covid at 6 feet or 60 feet in new study challenging social distancing policies

-The risk of being exposed to Covid-19 indoors can be as great at 60 feet as it is at 6 feet in a room where the air is mixed.

-Existing safety guidelines have omitted too many factors to accurately quantify the risk of airborne transmission, such as time, mask use and ventilation rates.

-Bazant and Bush question long-held Covid-19 guidelines that recommend 6 feet of distance between people.

The risk of being exposed to Covid-19 indoors can be as great at 60 feet as it is at 6 feet in a room where the air is mixed — even when wearing a mask, according to a new study by Massachusetts Institute of Technology researchers who challenge social distancing guidelines adopted across the world.

MIT professors Martin Z. Bazant, who teaches chemical engineering and applied mathematics, and John W.M. Bush, who teaches applied mathematics, developed a method of calculating exposure risk to Covid-19 in an indoor setting that factors in a variety of issues that could affect transmission, including the amount of time spent inside, air filtration and circulation, immunization, variant strains, mask use, and even respiratory activity such as breathing, eating, speaking or singing.

Bazant and Bush question long-held Covid-19 guidelines that recommend 6 feet of distance between people from the Centers for Disease Control and Prevention in a peer-reviewed study published earlier this week in Proceedings of the National Academy of Science of the United States of America. They say staying 6 feet away from another person may not be enough when people are inside for prolonged periods of time.

“We argue there really isn’t much of a benefit to the 6-foot rule, especially when people are wearing masks” since everyone in the room is breathing the same air, Bazant said in an interview. “It really has almost 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.”

Without masks, however, Bazant said 6 feet would provide some additional protection against Covid-19 versus 3 feet. That’s particularly true if a person is breathing directly in your direction, creating what scientists call a “respiratory plume,” like a puff of smoke from a smoker. Their research was based on models that assume the air in the room is “well mixed” and that “the pathogen is distributed uniformly throughout,” they said in a follow-up statement to CNBC on Monday.

In well-mixed spaces, “one is no safer from airborne pathogens at 60 feet than 6 feet,” they said.

The important variable CDC and World Health Organization guidelines have overlooked is the amount of time spent indoors, Bazant said. The longer someone is inside with an infected person, the greater the chance of transmission, he said.

Opening windows or installing new fans to keep the air moving could also be just as effective or more effective than spending large amounts of money on a new filtration system, he said.

Bazant also says that guidelines enforcing indoor occupancy caps are flawed. He said 20 people gathered inside for one minute is probably fine, but not over the course of several hours, he said.

Small, poorly ventilated spaces where a lot of people spend a lot of time together places people at the most risk, he said.

“Unfortunately, the nursing home is one of those cases. If Covid patients are living together 24/7, in some cases even in the same room, that is the absolute worst-case scenario, especially given the vulnerability of that population,” Bazant added.

On the other hand, their analysis shows that many places that were shut down didn’t necessarily need to close, he said.

“Often times the space is large enough, the ventilation is good enough, the amount of time people spend together is such that those spaces can be safely operated even at full capacity and the scientific support for reduced capacity in those spaces is really not very good,” Bazant said, citing some university classrooms. “I think if you run the numbers, even right now for many types of spaces you’d find that there is not a need for occupancy restrictions.”

Social distancing and occupancy rules that have resulted in closed businesses and schools are oversimplified, according to Bazant.

“This emphasis on distancing has been really misplaced from the very beginning. The CDC or WHO have never really provided justification for it, they’ve just said this is what you must do and the only justification I’m aware of, is based on studies of coughs and sneezes, where they look at the largest particles that might sediment onto the floor and even then it’s very approximate, you can certainly have longer or shorter range, large droplets,” Bazant said.

“The distancing isn’t helping you that much and it’s also giving you a false sense of security because you’re as safe at 6 feet as you are at 60 feet if you’re indoors and the air is getting well mixed. Everyone in that space is at roughly the same risk, actually,” he noted.

Pathogen-laced droplets travel through the air indoors when people talk, breathe or eat. It is now known that airborne transmission plays a huge role in the spread of Covid-19, compared with the earlier months of the pandemic where hand-washing was considered the leading recommendation to avoid transmission.

Artikel gaat verder:

https://www.cnbc.com/2021(...)et-in-new-study.html

Dit is iets wat velen van ons natuurlijk al wisten. Mooi dat het nu weer besproken wordt en dan nog wel door het gerenommeerde MIT

quote:

Op dinsdag 27 april 2021 20:52 schreef Red_85 het volgende:
Omt zal er wel weer met zijn eigen eigenwijsheid een oordeel over vellen.

Zoals altijd want de wetenschap is voor oa het rivm een lulverhaal.

Scientism noemt men dat tegenwoordig.