Is 6 feet enough? Health professionals question the wisdom behind social distance guidelines

Since the beginning of the pandemic, Health agency Worldwide, we encourage citizens to adhere to the 6-foot social distance rule. Keep at least 6 feet from strangers to limit the likelihood of coronavirus transmission. In fact, the “6-foot rule” has been inscribed in public awareness through signs, posters on restaurant walls, and verbal warnings from law enforcement.

New medical journal now paper Ask if 6 feet is really enough distance to avoid the transmission of the virus. Taken seriously, such recommendations can have far-reaching implications for public health and the behavior of everyday people.

An article published in the medical journal BMJ argues that the general public should adopt different criteria based on the specific details of the situation, rather than applying a single, consistent guideline for social distance. I will.

“Instead of a single fixed physical distance rule, we propose step-by-step recommendations that better reflect multiple factors that combine to determine risk,” said Oxford University of Technology, Massachusetts Institute of Technology, And the author of St. Thomas Hospital. “This not only provides better protection in the highest risk situations, but also allows more freedom in lower risk situations and may return to normal in some aspects of social and economic life. The authors include a photo of a gas cloud from a sneeze and show how it extends to about 7-8 meters (23 feet-26.2 feet).

Originally, the 6-foot rule was based on the idea that 2 meters (6 feet) was the range of transmission of aerosols containing pathogens, particles that can cause disease. But researchers say this may not always be true. They say that a person’s breathing force, the particular disease contained within the droplet, the size of the droplet itself, the ventilation volume in the area where the exhalation occurs, and the specific airflow pattern at those locations all affect Claims the variable of the distance that the aerosol travels to infect someone.

Next, the authors created a model that established the risk level of infection. The highest risk level they claim is for people who don’t wear face coverings in poorly ventilated or well-ventilated areas indoors. The lowest risk level is for people who are in a well-ventilated, low-occupancy area for a short time while wearing a face covering.

“Physical distances should be considered only part of a wider public health approach to contain the covid-19 pandemic,” the authors conclude. “It needs to be implemented with a combined human and air surface and space management strategy, including appropriate protection devices such as hand hygiene, cleaning, occupation, indoor space and air management, and masks for setting. There is.”

Aerosol experts have previously questioned whether 6 feet is sufficient to prevent infections, especially in indoor spaces. New York Times Published the simulation This shows how, through sneezing, the aerosol spreads far beyond the 6 foot radius of the sneeze and throughout the subway train.

The salon contacted public health experts, stressing that, in principle, people should still strive to maintain the rule of social distance of 6 feet or 2 meters.

“The 6-foot rule is still a valid guideline,” Dr. George Benjamin, director of the American Public Health Association, told Salon by email. “This will handle most of the droplet ejection. Aerosols are still a problem, but they are addressed by masks. This is a practical guide when possible. Masks are always part of layered protection. It should always be used, it’s all about risk mitigation, the only way to reduce risk is to not be around the infected person.”

He added that people should wear masks and wash their hands to stay safe from the new coronavirus.

Dr. Eric Faigledin, Senior Research Fellow of the American Federation of Scientists, e-mailed a similar idea to Salon.

“Social distance is still important, but not absolute,” Feigl-Ding explained. “In indoor aerosol propagation, I know it’s a real problem, because I know aerosols are infectious and can be found up to 27 feet away. is. [can] float [from] 20 minutes to 4 hours in the air. “

He argued that to protect themselves, people should also “in addition to masks, improve indoor ventilation and use indoor air filtration.”

Dr. Russell Medford, Chairman of the Global Health Innovation Center and Global Health Crisis Coordination Center, detailed these observations in an email to the salon saying, “People must at least strictly follow current CDC guidelines (Society (Distance, face mask and hand wash) must also have situational awareness for each of us to be aware of the relative risk of infection in different situations: indoors and outdoors, crowded areas and Uncrowded area, use (or not) of face masks by others, inadequate-ventilated indoor space, long and short contact.”

“For example, in high-risk situations (crowded, poorly ventilated indoor environments with few participants wearing face masks), keep social distances above 6 feet and minimize exposure time. We recommend that you keep it to the limit.”