Should workers wear face coverings in the office?
After months of working from home, small numbers of white-collar workers across the country are beginning to trickle slowly back to the office. But what kind of workplace will they find when they arrive, and will they be required to wear a face covering at their desk?
That was the recommendation of Dr Venki Ramakrishnan, the Nobel Prize-winning biologist and president of the Royal Society, who said last week that face coverings should be mandated for all indoor public settings. Currently, in England, face coverings are required on public transport (subject to a fine of £100), and the same will be true of shops from July 24. However, there will be no such advice for offices or other public places. Scotland, Wales, and Northern Ireland have different rules.
Dr Ramakrishnan’s comments came as new research published jointly by the British Academy and the Royal Society found that Britain is trailing far behind other European countries in its uptake of face coverings – although the situation might have changed since late April, when the study was carried out.
What are the current rules of the office?
Every company with more than five employees that is bringing staff back to work has a legal duty to carry out a written assessment to weigh up its coronavirus risks.
Virologists have generally been working on the assumption that SARS-CoV-2 – the virus that causes Covid-19 – is not airborne, meaning that tiny, floating particles of the virus (known as aerosols) cannot linger in the air for long enough to infect people. Instead, they say the most likely route of transmission is if somebody coughs or sneezes in your close vicinity, and their droplets land on a wet part of your face – your eyes, nose, or mouth.
As a result, public health experts have advised employers to focus on social distancing and hand-washing as the key tools to fight the virus. Keeping staff at least two metres apart, it is thought, should prevent one employee’s cough droplets from infecting another. This is why offices in the UK have implemented one-way systems, staggered arrival times, and barriers between desks - but the UK has not joined the ranks of the 50 or so countries, including Poland, Austria, Argentina, and Israel, who have mandated face coverings in public places.
What if the virus is airborne?
But now that assumption is being challenged. In an open letter this week, more than 200 top scientists accused the World Health Organisation (WHO) of under-estimating the likelihood of airborne transmission. A WHO official later admitted that airborne transmission cannot be ruled out in crowded and poorly-ventilated settings.
In a small study published in the journal Nature Research in May, researchers set up “aerosol traps” around two hospitals in Wuhan, China, and found bits of the virus’s genetic material floating around indoor toilets, as well as a room in the hospital where medical staff removed their masks, gowns, and gloves – although the study did not try to answer whether those virus particles were actually causing infection (they might have been dead or degraded particles).
“The issue is that although there isn't a lot of definitive evidence that the virus is airborne, certainly there's no evidence that it's not,” says Prof Babak Javid, Associate Professor at the University of California and expert in infectious diseases. “Lack of evidence doesn't mean evidence of lack. Traditionally, ‘airborne’ means that you can get infected by somebody 50 metres away, or who is not even in the room anymore, and certainly there's not any evidence for that for Covid. But it could well be that poorly-ventilated indoor spaces, especially with a lot of people in them, are a risk factor for transmission."
The virus being airborne raises the prospect that social distancing in an indoor setting like an office might not be as protective as previously thought, because SARS-Cov-2 particles could linger inside for hours, slowly spreading throughout the room.
Are office masks a good idea?
Experts stress that no single tool, whether it is meticulous hand-washing, social distancing, or face coverings, can by itself guarantee protection. Instead, it is about finding the right balance – and some scientists think that face coverings are a relatively small sacrifice.
“If it was me, I would wear a mask,” says Prof Javid, who has just started a new job at the University of California, where he will be required to cover his face on the San Francisco campus. “It's difficult to say anything with certainty, but I would say there's relatively few downsides to wearing a mask – they’re uncomfortable but otherwise they're an effective and easy measure. It's certainly possible that in a high-density indoor environment there might be some risk of transmission, even with distancing.
“I would say an office environment is higher risk than going shopping, so if we think it's sensible to wear a mask inside a supermarket, it's certainly sensible to wear a mask in an office with your co-workers.”
Speaking is also a risk factor for transmission, he says, “so an office environment will tick those boxes without any doubt”.
But Kelvin Williams, president of the British Occupational Hygiene Society (BOHS), shies away from a blanket recommendation and prefers judging each workplace on a case-by-case basis. For example, face coverings could be a good “extra layer” of protection in an office in which social distancing is particularly difficult, he says.
In its official guidance, the BOHS says there is “some evidence that face coverings will offer marginal benefit to others in close proximity to the wearer”, and says they could be “reassuring to workers”. Although it warns that face coverings should not be seen as a “substitute for good social distancing measures”.
Williams says: “I've visited many office spaces in the last two or three months and people have been following government precautions, they've been doing the distancing, they've been washing their hands, just as Public Health England has recommended. I'm not aware of workplaces like that having problems with spreading the virus, but of course the absence of evidence is not evidence of absence.”
Evidence for the efficacy of face coverings is unclear, he says. “I've got research papers in a box behind me that can show you face coverings being demonstrated to have no effect whatsoever, and another research paper saying they offer X level of protection and it's worth having it, and every other opinion in between, which isn't helpful. But if you look at the large, macro data, you can see that countries that have mandated it appear to be in better control of the pandemic than countries that haven't.”
Williams says that much also depends on the level of ventilation in the office – a well-ventilated space in which fresh air is allowed to circulate carries a much lower risk of transmission than a stuffy, poorly-ventilated one. Face coverings could be a good addition in an office with poor ventilation, he adds.
