IT seems as if there is a widespread lack of understanding among politicians, advisers and the general public, of relative as opposed to absolute risk as far as the two-metre distancing rule is concerned ("Expert calls for social distancing rules to be relaxed to one metre", The Herald, June 16).

We are repeatedly told that going from two metres to one metre is thought to double the risk of infection from contact with an infected person. In relative risk terms this doubles it from 1.5 per cent at two metres to 3% at one metre.

However, this would mean that everyone you met would have to be infected.

As it is now thought that one in around 1,500 (or less) of the population is infected, then the combined risk of catching Covid is either: (3/1,500)% at one metre or (1.5 /1,500)% at two metres.

This translates to an absolute risk of a 1 in 50,000 chance of infection at one metre as opposed to a 1 in 100,000 chance at two metres.

It is a matter of great regret that we are not adequately appraising the public of these odds and letting them make a reasoned adult choice of whether the damage to the economy, tourism, the arts, children’s futures and education, and the looming crisis of deprivation and poverty warrants continuation of the two metre rule, when the "worst" scenario is a 1 in 50,000 chance of infection.

Joan Noble, Nairn.

SCIENTISTS and mathematicians always have to operate on being 100 per cent accurate. It is an ingrained attribute which can lead them to considerable frustration with the variances found in an imperfect ordinary existence. Perhaps Nicola Sturgeon should reflect on why so few scientists manage large businesses, companies or countries. They cannot cope with risk and imperfection. To do so requires different skill sets from purely scientific ones. The business of life is not for the risk-averse, and most managers of large organisations are content if their decisions are correct 85 per cent of the time.

Perhaps Ms Sturgeon now needs to bite the bullet, calculate the odds, accept the WHO one metre distancing rule, get the schools, pubs and shops open, and let us all get on with our lives in this imperfect, risky, unscientific world!

Elizabeth Marshall, Edinburgh EH66.

I THINK that we must now accept that Covid-19 is here to stay, that it cannot be eliminated until an effective vaccine is developed and the majority of the population are vaccinated. This being the case, if we are to avoid a total collapse of our society, we must lift lockdown now and be prepared to accept that Covid-19 will take some more lives. On the other side of the "social balance sheet" our children will be back in school, the mental health issues surrounding lockdown will ease, sufferers from other health conditions will get their necessary and overdue treatment and with businesses reopening and people back at work, the economy can slowly start to recover.

To help the more timorous, it would be a good idea for the Government to underwrite claims against employers for risking the health of employees by failing to guarantee a coronavirus-free working environment. To support this, we need to put more resources into "test, track and trace systems" and do a basic temperature check at all UK ports of entry.

After all, in a democracy like ours, government policy should deliver the greatest good for the greatest number.

John Breckenridge, Kilmarnock.

DAVE Gordon (Letters, June 17) clearly does not understand the difference between rules and guidance concerning the distance that one can travel during the current restrictions on our activities.

The rules and regulations do not prevent Mr Gordon travelling 20 or 30 miles to go hill walking. The guidance is that he should not travel more than five miles, and given the proximity of post offices and food shops to his home he has been able to adhere to that advice when he had to visit these establishments. In the case of hill walking, Mr Gordon has to travel further than five miles in order to reach the nearest suitable hills for him to climb. If I were him I would head to Dunkeld, but living in the north of Edinburgh I will have to restrict myself to slightly more than five miles to reach the Pentland Hills. I suggest that both Mr Gordon and I put any plans for climbing Ben Nevis on hold until restrictions are relaxed.

Sandy Gemmill, Edinburgh EH3.