One meter or two? How social distancing affects COVID-19 risk

By Kate Kelland

Britain this week announced an easing of social distancing rules from July 4, reducing the recommended gap from 2 meters to "1 meter plus" as it further loosened lockdown measures meant to curb the COVID-19 pandemic.


Infectious disease experts say the closer people are to someone infected with COVID-19, and the more time people spend in close quarters, the higher the risk that the coronavirus will spread from one person to another.

Beyond that simple reality, "it is just a matter of reducing risk with increased physical distance", said Jonathan Reid, a professor of Physical Chemistry at Britain's Bristol University.

"The further you stand away from someone, the fewer droplets you will be exposed to. One meter only prevents you from being exposed to the largest of droplets; two meters reduces your exposure - but doesn’t make it zero risk."

A study in The Lancet this month found that physical distancing of at least one meter lowers risk of COVID-19 transmission, but that two meters could be more effective.


The WHO says keeping a distance of at least one meter helps reduce the risk of the coronavirus spreading in the small liquid droplets that people spray out when they cough, sneeze and talk.

These droplets may contain the virus, and "if you are too close, you can breathe in the droplets", the WHO says.


Switzerland's health ministry says that "according to current data, a distance of more than one meter reduces the risk of COVID-19 infection by more than 80% in both healthcare(settings) and everyday life".

It added, however, that the risk is higher "in circumstances in which a particularly large number of droplets are expelled, such as when singing or speaking loudly".

Shaun Fitzgerald, a professor of engineering at Britain's University of Cambridge, said the key point is that "it's not all about the distance".

"There are other mitigation measures," he said - including the duration of close proximity, the number of people in a given space, the use of face masks, availability of ventilation, and whether people talk quietly or shout loudly.


China, Denmark, France, Hong Kong and Singapore recommend social distancing of one meter, and many people also choose to, or are required to, wear face masks in public spaces.

Australia, Belgium, Greece, Germany, Italy, Spain and Portugal advise people to keep 1.5 meters apart. Switzerland this week also reduced the required distance to 1.5 meters from two meters.

The guidance in the United States is six feet, or 1.8 meters.

© Thomson Reuters 2020.

©2020 GPlusMedia Inc.

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I remember from physics class that doubling the distance from a radiating object reduces the radiation impact by 75%. Something similar could apply to virus transmission via droplets. In other words, politicians shouldn't set themselves up as health advisors without first checking with scientists and doctors.

1 ( +3 / -2 )

My immune system says... No effect cos it takes care of it... Millions of different viruses every day... Lol...

0 ( +5 / -5 )

The more the better.

But practically speaking, one meter is already hard to maintain.

0 ( +1 / -1 )

Yelled at an oyaji yesterday for being right up my backside in a queue. Nobody else in the queue. Either they don't get it or they think its all safe now because the emergency was withdrawn. Or they really don't care.

I lost it because I told him once. Then he continued to stand right behind me. They even have distancing tape on the floor. He is fortunate that for a foreigner getting arrested for knocking someone out in a cafe is extremely bad news for said foreigner. Back home I would have just knocked him out.

2 ( +3 / -1 )

I don't understand the logic of 1m separation in lines, if you are facing forward even if the person behind you coughs on your back, you aren't going to get infected unless you then touch your neck and lick your hands.

Worst case you have to rub a little alcohol on your neck if your worried.

-2 ( +1 / -3 )

Who can trust the WHO and the medical expert panel when they cant even find a solution while they use us all as guinea pigs... Really one meter droplets. have we forgotten that a mask wont prevent contraction because the virus can float around and enter your eyes and even attach to your clothes. If you really want to disinfect you need to burn your clothes with a flame thrower before entering your home. Peeps keep forgeting that the virus can launch onto your clothes, and commissary items you go out and buy. No way to prevent the spread.

-2 ( +0 / -2 )

I don't understand the logic of 1m separation in lines, if you are facing forward even if the person behind you coughs on your back, you aren't going to get infected unless you then touch your neck and lick your hands.

I think I'll stick with the people who don't start their assertions with 'I don't understand the logic...' that scientists are putting out there.

4 ( +4 / -0 )

This is hilarious. Only someone with the IQ of a potato would say that 1 meter is ok now. Did they write a memo to the virus tasking it to comply with this new information?

4 ( +4 / -0 )

Well, all these rules are completely arbitrary bs called security theater, including all the global lockdowns.

There is no hard evidence that anything of it works, but if we make it obligatory, if we enforce these rules and make it official, then it means it works, right?

Basically governments and the Who did a 180 degree change of their long standing recommendations when people started to heavily criticize them because of pure panic.

UK, from a strategy targeting the vulnerable population, and letting those who aren't really vulnerable to continue with their lives normally, to one of the most harsh and restrictive national total lockdowns in a question of hours

-3 ( +0 / -3 )

There is no hard evidence that anything of it works,

That is incorrect and outright wrong.

2 ( +2 / -0 )

Well, all these rules are completely arbitrary bs

No, they're based on scientific principles behind the degree to which the virus can propagate as droplets and/or aerosols in the air and reach another person.

But once again we have a poster on JT dismissing science because they don't understand it.

0 ( +0 / -0 )

There is no hard evidence that anything of it works

What? Yes there is. Countries that have been practicing social distancing and proper prevention measures have brought the virus under control.

1 ( +1 / -0 )

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