A STUDY OF almost 8,000 cases of different coronaviruses has found that there is a “much lower risk” of transmission when physical distance is greater than one metre.

The study also outlines that the wearing of face masks is not an alternative to physical distancing or basic measures to prevent the spread of Covid-19, such as hand hygiene.

The risk of Covid-19 infection is as low as 3% when people stand more than a metre away from an infected individual, compared to 13% when the distance is within a metre, according to the study published in The Lancet.

The modelling also found that for every extra metre further away up to three metres, the risk of infection or transmission may halve, with no conclusions as to whether distances of more than two metres were more effective.

It comes amid recent debate in Ireland about physical distancing, with calls to halve the two metre distance to allow businesses to re-open and for an increase in the capacity of the health service.

However, Chief Medical Officer Dr Tony Holohan told ministers last week that he does not intend to advise a reduction of the distancing rule to one metre. 

The study analysed data from nine studies of SARS, MERS and Covid-19 made up of 7,782 participants, and its authors noted that the certainty of their evidence on physical distancing is moderate.

It was carried out to inform World Health Organisation guidance, and is the first time researchers have examined the use of protective measures in both community and healthcare settings for Covid-19.

It found that although physical distancing, face coverings and eye protection could be the best way to reduce the transmission of Covid-19, none offered complete protection, even when they were properly used and combined.

Thirteen studies across all three viruses which focused on eye protection found that face shields, goggles, and glasses were associated with lower risk of infection, compared with no eye covering at all.

However, the study’s authors noted that their certainty of the evidence for eye coverings is low.

Meanwhile, evidence from ten studies across all three viruses found similar benefits for face masks in general.

The risk of infection or transmission when wearing a mask was found to be 3% compared with 17% when a mask was not worn – although the evidence for this was based on low certainty.

The authors also noted that there were concerns that mass face mask use risked diverting supplies from health-care workers and other caregivers at the highest risk of infection.

“We believe that solutions should be found for making face masks available to the general public,” co-author Dr Derek Chu of at McMaster University said.

“However, people must be clear that wearing a mask is not an alternative to physical distancing, eye protection or basic measures such as hand hygiene, but might add an extra layer of protection.”

In Ireland, current government advice is that people should wear face coverings on public transport, in supermarkets or other situations where it is difficult to practice social distancing.

The government has requested that PPE masks and medical/surgical masks, which are of a higher regulatory standard than cloth face coverings, be reserved for use in healthcare settings.

The Competition and Consumer Protection Commission has today issued new guidance for Covid-19 face coverings for use in the community.