Skip to main content



commentary Commentary

Commentary: Safe distancing matters, but is no magic number to keep us safe from COVID-19

A fixation on specific distances encourages a false, binary distinction between safety and danger, says Anjana Ahuja.

Commentary: Safe distancing matters, but is no magic number to keep us safe from COVID-19

A park worker paints circles to help visitors maintain social distancing to slow the spread of the coronavirus, at Trinity Bellwoods park in Toronto, Ontario, Canada. (REUTERS/Chris Helgren)

LONDON: Only a fool breaks the two-metre rule. This has been the mantra in the UK, where painted pavements and supermarket signage urge people to stay two metres apart to prevent coronavirus infection.

The rule is now under review in the UK, to the relief of ministers and business people who foresee a bleak future for a hospitality and entertainment industry that is currently without a critical mass of customers. 

They favour the World Health Organization’s 1m recommendation, which has already been adopted by China, Hong Kong and Denmark. A decision is due in early July, when more sectors of the British economy are scheduled to reopen.


The fixation on distance usefully highlights a persistent theme in the public discussion of risk: A false, binary distinction between safety and danger.

No magic attaches to either distance: Some countries, including Australia, Belgium and Germany, have opted for 1.5m. The choice is not whether to be safe at 2m or unsafe at 1m - but whether we want to take more risk or less, and to what end. 

READ: Commentary: Why are COVID-19 death rates in the UK so high?

LISTEN: TraceTogether token and contact tracing apps: Privacy, data usage and other big questions

Reopening the economy before the virus is conquered means governments taking tough decisions on how society should function in a landscape of uncertain risk.

Uncertainty should not, however, mean junking the precautionary principle, given that COVID-19 is still springing unwelcome health surprises. For example, since we know some people can carry the virus without showing symptoms, we must assume they can also transmit it until proven otherwise.

Social distancing signs are seen at the entrance of Chester Zoo which remains closed despite a partial easing of restrictions as the spread of the coronavirus disease (COVID-19) continues in Chester, Britain, June 4, 2020. REUTERS/Phil Noble

This is the most convincing argument for donning face coverings or masks, especially indoors and on public transport, where distancing can be difficult. 

It is, mostly, an act of consideration towards others: Face coverings prevent the projection of virus-laden droplets towards people and surfaces, where others can pick them up - the WHO recommends fabric coverings made of three layers of different materials, rather than medical masks. 

Face coverings might also be important given the continuing disagreement over airborne transmission via aerosol particles that are finer than the droplets emitted in coughs and sneezes and which can hang in the air for longer.

READ: Commentary: Why are advanced countries experiencing world’s highest COVID-19 death rates?

READ: Commentary: As the EPL kicks off, be prepared for a very different second half


A highly contested paper published last week suggested that such transmission was not only likely but dominant. 

Still, it is worth noting the pro-mask attitude in countries that have kept infection rates relatively low: There is no shame in copying measures for which there seems to be a rationale.

When it comes to social distancing, timing as well as distance is critical. Spending six seconds at one metre from an infected person carries roughly the same transmission risk as spending a minute at two metres, according to Patrick Vallance, chief scientific adviser to the UK government.

The risk continues to fall with distance. Outside is safer than inside because breezes disperse droplets and aerosols.

READ: Commentary: Immobility during COVID-19 and its effects on our sleep, physical activity and well-being

READ: Commentary: When gyms finally reopen, can we get rid of toxic gym culture?

Superspreading events have mostly been documented indoors — such as in nightclubs, gyms and churches - shouting, heavy breathing and singing all propel droplets further.

Avoiding indoor meetings also cuts the chance that an infected visitor will leave traces of virus on surfaces for others to pick up.


These precautions, and others, matter because, in order to infect someone, the virus must physically enter the body via the mouth, nose or eyes. 

Every mandate or recommendation — including social distancing, face coverings, meeting outdoors, indoor ventilation, handwashing, cough etiquette — is designed to cut the chances of that happening.

A sign tells passengers to 'wear a face covering' at Waterloo train station in central London , on Jun 8, 2020, as the UK government's planned 14-day quarantine for international arrivals to limit the spread of the novel coronavirus COVID-19 begins. (Photo: AFP / Justin Tallis)

While public discussions tend to fixate on them singly, they are meant to be applied together — and in conjunction with a strong disease surveillance system to detect new outbreaks.

READ: Commentary: The systematic testing Singapore needs to ditch circuit breakers for good

READ: Commentary: Is COVID-19 the final straw that breaks the Orchard Road camel’s back?

Still, the resurgence of the virus in Beijing, which had gone 50 days without a new case, is also a portent that we will be living amid uncertainty for many months to come.

Until a vaccine arrives, deciding whether to shrink social distancing to expand the economy will be just one of many imperfect risk calculations on the table.

BOOKMARK THIS: Our comprehensive coverage of the coronavirus outbreak and its developments

Download our app or subscribe to our Telegram channel for the latest updates on the coronavirus outbreak:

Anjana Ahuja is a contributing writer on science for the Financial Times. She is co-author of Selected, on the evolution of human leadership, and was named best science commentator in the 2013 Editorial Intelligence Comment Awards.

Source: Financial Times/ml


Also worth reading