Understanding Social Distancing: How Far is Enough?
The coronavirus pandemic is still ongoing—with more than 200 countries currently reporting over nine million total cases.5
The spread of the virus caused many federal and state governments to issue lockdown and stay-at-home orders for their citizens and inhabitants, but some states are now beginning to ease restrictions. As summer begins and the desire for interaction increases, it's important to review the latest guidelines for protecting ourselves and others.
What is social distancing, and why practice it?
Social distancing, also known as physical distancing, is the practice of keeping distance between yourself and people you don't live with. It also involves avoiding groups, gatherings and crowds in both indoor and outdoor spaces.1
There's a lot that's still unknown about the coronavirus. Still, public health experts and researchers have found that limiting close contact between people is one of the optimal ways to slow the spread of COVID-19.1 And, although people can contract COVID-19 by touching their noses and mouths with hands that have been exposed to the virus through surfaces and objects, this is not thought to be the primary way the virus spreads.1
Instead, exposure to droplets that are dispersed into the air when an infected person coughs, sneezes or talks are thought to be the main drivers of the virus' spread. The droplets can settle in the noses and mouths of people close by and can even be inhaled into the lungs. This mode of transmission is what makes social distancing necessary.1
The Inexact Science of Social Distancing
The CDC recommends that you keep at least six feet between you and others. This is about 1.8 meters and the equivalent to two arms' length.1 The recommendation is based on the fact that COVID-19 seems to spread mainly among people who are within about six feet of each other (and more vulnerable to coming into contact with those droplets) for extended periods.1 Other respiratory illnesses like influenza also spread this way.3
However, not all organizations and research bodies agree on a specific distance people should maintain. The World Health Organization, for instance, advises people to stay three feet away from others.2
In contrast, scientists in a recent study contend that these droplets travel much farther than six feet— sometimes as far as 27 feet.4 The study used a new model of understanding respiratory emissions. And it found that, depending on environmental factors like temperature, humidity and a patient's unique physical make-up, exhaled droplets containing pathogens could travel up to 23 to 27 feet.
The study also noted that current public health recommendations for slowing the spread of viruses are based on older models of disease transmission.
So, which guideline should you follow? Keeping at least six feet between you and others around you is likely to significantly lower your chances of infection.6 Due to limited evidence, further research is needed to better understand these protective measures. The farther you are, though, the less likely you are to come in contact with infectious respiratory droplets.
Additionally, other preventative measures (like wearing a mask or face covering outside of the home and washing hands often) can also substantially reduce your risk of getting COVID-19.7
Sources
1. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/social-distancing.html
2. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/advice-for-public
3. https://www.cdc.gov/flu/about/disease/spread.htm
4. https://jamanetwork.com/journals/jama/fullarticle/2763852
7. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/prevention.html