There’s been a lot said about face masks since Boris Johnson announced they’ll no longer be legally mandated from July 19 – not least by the government.
Nadhim Zahawi told Sky News on Sunday that people will still be “expected” to wear masks in enclosed indoor spaces even if the legal requirement if lifted.
Some are feeling anxious about any changes to policy – particularly those with disabilities or chronic illnesses, who are more vulnerable to the virus. And for those who’ve yet to be double-vaccinated, any lifting might feel too soon.
But others have been looking forward to face mask rules relaxing – particularly those who find it harder to communicate with masks on, or those who find them uncomfortable during long, hot work days.
Some experts have said we should continue wearing masks, but most agree that some settings are more important and impactful than others – to protect yourself and others.
“Outdoors, unless somebody infectious is shouting (or singing) in your face, transmission is negligible,” says Dr Peter English, a retired consultant in communicable disease control and past chair of the BMA Public Health Medicine Committee. “Indoors it’s much more likely. The more crowded, and the less volume of air, the greater the risk.”
We asked experts in the field to share the key indoor settings where they’d recommend keeping your mask on.
“Supermarkets are number one, because everybody goes there and there’s no social distancing, let’s be honest about that,” says Dr Julian Tang, an honorary associate professor and clinical virologist at the University of Leicester
“If you can keep the mask on, that will reduce the cross-transmission rate, especially with the Delta variant and the Delta plus variants appearing.”
As well as considering vulnerable customers around you, you should also spare a thought for supermarket workers, some of whom see thousands of people per week in busy stores. We need supermarket staff well to keep shops functioning – so keep your mask on.
2. Where people may be more vulnerable
Professor Paul Hunter, an expert in infectious diseases at the University of East Anglia, says you should consider how vulnerable you are to Covid-19 and the potential vulnerability of those around you.
“What I would say is that if you are in a vulnerable group and are going into a crowded indoor environment then it is sensible to still wear one [if] Covid is common in the community, at least whilst infection rates are high,” he says. “Also if you are visiting a very vulnerable individual indoors when Covid is common in the community then I would wear one for their protection, even though I have been fully vaccinated.”
Of course, there’s a chance someone around you could be vulnerable in any setting, from the supermarket to a restaurant. But you should take particular care in settings such as hospitals, doctor’s surgeries, care homes and hospices, or when visiting the home or someone at-risk.
3. Cinemas and theatres
Cinemas and theatres are another area of concern, as you (usually) can not open a window to better ventilate the space.
It’s tricky to maintain social distancing while making your way to your seat, says Dr Tang, who pinpoints the ticket queues and the shuffle down the aisle to your chair as two potential moments for transmission.
But even when you get to your seat, there are issues. Currently, venues are running with limited capacity, with spare seats being used to separate customers. Although that might help limit some transmission, is doesn’t make the activity risk-free.
Dr Tang uses the “garlic breath vs burnt toast” analogy to explain this. If you can smell the breath of the person next to you, aka garlic breath, then you’re going to breathe in any virus that they exhale. But even if you can’t smell their breath, you’re still sharing the same air in an unventilated space.
“Just like if you burn some toast in the kitchen, after a while, the whole kitchen smells of smoke. So, without ventilation, that whole air volume will fill with the virus over some time,” he explains. “If you’re watching a two or three hour movie, even if you’ve got every other seat occupied, that’s not going to stop you from the burnt toast mechanism of inhaling the virus. Everybody in the room is breathing from the same air volume.”
The risk in these settings will only increase once entrance capacity is upped, which is why Dr Tang recommends wearing a mask whenever you’re not eating.
4. Classrooms and offices
Secondary schools across most of England ditched face masks when the official rules changed on May 17, but some schools have asked pupils to continue wearing masks, due to concerns over the Delta variant in their area. Meanwhile, masks have never been mandated in offices, although some companies have chosen to introduce their own policies.
Dr Tang believes wearing masks in both settings would be helpful, particularly with cases rising and the “work from home” order due to be dropped.
“In offices and classrooms, ideally you should keep masks on, because we’ve seen what’s happened with the secondary schools abandoning masking – the numbers are going up,” he says. “Classrooms are pretty crowded – you’ve got 30 people plus a teacher – if you open a window that’s better, but if you can keep a mask on during lessons, it’s even better than that.”
He gives us a quick maths session to prove just how much we breathe in each other’s air in such settings.
“Let’s say you have an office that’s 10m by 10m by 2m high, that cubic volume is 200m³. That 200m³ translates to about 200,000 litres [of air]. Say if you have 10 office workers in there, that’s 20,000 litres of air each, which sounds like a lot, but you’re breathing 12-15 breaths per minute. If you divide 20,000 by 60 for minutes, then 60 again for seconds, that’s only 5.5 litres per second per person – and ideally what you want is 10 litres per second per person.”
In short: it’s stuffy, especially if you’re sitting in the same spot for an eight-hour working day. Opening windows will help, but Dr Tang says many offices and classrooms are not designed for optimum cross-flow ventilation, so masks should be considered.
5. Public transport
There are similar – if not worse – problems when ventilating public transport. If you’re on a bus or sharing a car, Dr Tang recommends opening all the windows. But if it isn’t possible, e.g. on a train, you should continue wearing a mask.
This is something Dr English also feels passionately about. “Anybody who refuses the minor imposition of wearing a mask in such places is placing vulnerable people at risk, effectively barring them from entering such spaces – and if you can’t travel on public transport, that is a massive imposition,” he says.
6. Restaurants and pubs
There’s been much public debate on whether it’s actually worth wearing a face mask as you enter a pub or restaurant – particularly as we tend to whip them off the moment we reach our table.
Because of this, Dr Tang places these settings lower on the priority list for mask wearing. Masks simply can’t be used when eating or drinking, so instead, Dr Tang says venues should be working to improve their ventilation and recommends bagging a spot by an open window or door where you can.
If you do want to be extra considerate – particularly if there’s a vulnerable person on your table – you might want to re-mask after you’ve finished your meal while you’re chatting, he says. This is already customary in other countries.
Tempted to jet abroad following the relaxation of amber isolation rules? You might still want to pack a mask for the plane.
“Aeroplanes are relatively safe, because they have massive ventilation systems, but I’d still wear a mask on a plane when you’re not eating or drinking, because of the immediate ‘garlic breath’ distance,” says Dr Tang.
“If you can tolerate wearing a mask when you’re watching a movie or sleeping, it’s also going to be safer for you, especially with the different variants circulating around the world. If you’re on a plane, you could be with passengers from any part of the world carrying anything.”
He adds a reminder that the vaccines currently in circulation were designed “only for the first generation virus,” and while most seem to be effective against the variants to date, this is an area still being researched. A mask won’t completely block transmission, but it may help reduce the risk.