The ‘outdated’ social-distancing measures like temperature checks that aren’t just annoying – they won’t protect you
Floor tiles, signs and posters urge us to ‘KEEP A SOCIAL DISTANCE’, while arcane one-way systems stop us from passing one another. Sinks have been taped up, just in case we get too close while carrying out all-important hand-washing, as have some of the urinals in the men’s loo, presumably to mitigate the Covid risk of standing next to someone while having a pee. And that’s just in my office.
It’s a picture being seen in workplaces and public spaces up and down the country.
Government advice, for almost a year now, is that we should all stay at least two metres away from anyone we don’t live with.
Government advice, for almost a year now, is that we should all stay at least two metres away from anyone we don’t live with
The idea is that, if we are far enough apart, we’ll avoid transmitting the virus. And if we can’t be, there’s always those plastic screens that seem to have been erected everywhere to protect us. But is it that simple?
Social distancing policies have been instigated by many businesses at the start of the pandemic. And as Britain edges out of lockdown, they remain unchanged.
But the science has moved on, and for months experts have been urging the Government to reconsider the approach – warning that these measures alone won’t prevent infections. One leading public health researcher, speaking to this newspaper, went as far as to brand many of rules ‘well meaning but pretty much useless’.
Last week we revealed how workplaces were ignoring Public Health England guidance by relying on temperature checks – which had been found to be inaccurate and ineffective at picking up Covid cases.
Could a fixation with one-way systems and two-metre rules also present a similar problem? Giving the illusion of safety, while distracting us from the true risks?
Part of the problem lies in the fact that, initially, it was believed Covid, like colds and flu, is mainly transmitted through coughs and sneezes. When sprays of tiny moisture droplets carrying the coronavirus are expelled this way, they can land on other people and potentially infect them. But these droplets are also subject to the laws of gravity – they travel just a metre or so before falling to the ground.
The idea is that, if we are far enough apart, we’ll avoid transmitting the virus
Mask-wearing is a vital measure to mitigate the risk of this sort of transmission – they block droplets from being expelled from the mouth and nose. This became particularly relevant when it emerged that large numbers of people with Covid get few, if any, symptoms but are still potentially infectious.
But it has become increasingly clear that droplets are not the only way the disease spreads. Infection also occurs from so-called airborne exposure to the virus.
Microscopic viral particles can remain hanging in the air for hours, like smoke, experts have warned. Outdoors, these particles are quickly blown away.
But indoors, without adequate ventilation, this viral ‘smoke’ rapidly builds up.
Again, masks can mitigate this to a degree, soaking up some of these particles. But they aren’t 100 per cent effective, and this means that simply being in the same room for any length of time with someone carrying Covid poses a risk, no matter how far apart you are.
Studies of super-spreader events – of which there have been many – are proof of this.
In March last year, there were reports that 50 people who attended a choir practice in the US state of Washington for an hour and a half were subsequently diagnosed with the virus. Two of them died.
And then there are the outbreaks in meat factories. Researchers who studied a slaughterhouse in Germany, where about 1,500 workers contracted the virus, suggested cold and stale air conditions allowed coronavirus particles to travel more than 26ft.
In December, an outbreak in Adelaide, Australia, was traced to a security guard at a quarantine hotel. After examining CCTV footage, it was concluded he caught the virus by standing outside the room of a Covid-positive couple. Health chiefs said poor ventilation was to blame. The list goes on and on.
Mask-wearing is a vital measure to mitigate the risk of this sort of transmission – they block droplets from being expelled from the mouth and nose
In a study, researchers had a young woman who’d tested positive for Covid, but had mild symptoms, drive a car that contained a virus-detecting sensor.
It was still picking up viral particles in the air two hours after she had got out.
This, perhaps, explains why during the first wave of the pandemic, in the UK, men who worked as cab drivers were found to be most likely to die from Covid.
In October the US Centres for Disease Control updated its guidance on Covid transmission, recognising that airborne transmission can occur in enclosed, poorly ventilated spaces.
Prof Trish Greenhalgh said: ‘Distancing round the sinks and urinals would only work if the mode of transmission were limited to droplets. The virus is airborne. We need to ventilate to reduce its transmission’
A month later more than 200 scientists signed an open letter urging all public health authorities to recognise the potential for airborne spread of Covid-19. They highlighted numerous studies that had proven the virus could easily travel more than 30ft.
Due to the tiny size of these particles, they settle in the air at a height of about 5ft, research suggests.
Last week, the Government updated its ‘hands, face, space’ slogan to include ‘fresh air’ – acknowledging that being outdoors presents the lowest infection risk. But what about the air in offices and shops, and, soon, pubs and restaurants?
Cath Noakes, a professor of environmental engineering for buildings at Leeds University who campaigned for the slogan change, warns: ‘The virus is carried in people’s breath. If you’re close to someone who’s infected, you are at higher risk, so social distancing does matter. But it only deals with part of the risk.
‘If you are indoors, in a poorly ventilated space, viral particles build up and we breathe them in.’
The Health and Safety Executive says the law requires employers and business owners to open windows or install mechanical ventilation – fans and ducts that bring in fresh air from outside.
‘Spaces that are most risky are those that have no mechanical ventilation, or access to open windows and doors,’ says Prof Noakes.
‘In pubs, restaurants and other small businesses, there are a lot of spaces like this.
‘Mask-wearing in these settings will help a bit, but they don’t mitigate the risk completely.’
Without good ventilation, those social-distancing stickers, one-way systems and desk-dividing screens – ‘Ah, the magic screens,’ Prof Noakes chuckles – are fairly futile.
Prof Trish Greenhalgh, a University of Oxford public health expert, was even more critical of many social-distancing measures.
She says: ‘Distancing round the sinks and urinals would only work if the mode of transmission were limited to droplets. The virus is airborne. We need to ventilate to reduce its transmission.’
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