Face masks are the new normal in many parts of Canada. But some experts believe there is a more effective, cheaper and more accessible way to protect yourself from COVID-19: face shields.
Clear and plastic, face shields are tightened around the forehead, cover the entire face and extend below the chin. They are also relatively inexpensive, with costs as low as $5 per shield, depending on quality, at everywhere from Walmart to Amazon. Whereas face masks can also run below $10, shields are reusable and you really only ever have to buy one if you disinfect it effectively.
Health-care workers have already begun wearing them, often over top of their N95 face masks as an extra precaution, as have numerous other frontline workers.
They’re catching on in other parts of the world: in Singapore, students and teachers will be provided face shields when school begins this summer, while teachers in California have requested them, and a policy review by Children’s Hospital of Philadelphia has strongly recommended them.
However, Canada hasn’t touched face shields in federal government health guidelines.
How effective are they?
In a recent opinion piece published in the Journal of the American Medical Association (JAMA), an Iowa City-based team of doctors and public health experts said they believe face shields, “if universally adopted,” could help reduce the transmission of infections to below a critical threshold – if used alongside increased testing, contact tracing and hand hygiene.
After all, shields protect the entire face and make it difficult for people to touch their face if they feel an urge to do so. And if the wearer sneezes or coughs, the droplets emitted will be blocked by the shield and directed downwards, preventing them from flying forward and endangering others.
In a 2014 cough simulation study, face shields were shown to reduce immediate viral exposure by 96 per cent when worn by an individual within 18 inches of a cough. Even after 30 minutes, the protective effect exceeded 80 per cent and face shields blocked the majority of small particles. When the study was repeated at the currently recommended physical distance of two metres, face shields reduced exposure by a still impressive 92 per cent.
But with relatively little data on how to appropriately use shields when it comes to infection control, the research we do have strongly encourages that, if we are to use face shields, they must be in conjunction with other personal protective equipment.
Face shields vs. face masks
A lot of things stand in favour of face shields over masks: they’re easy to take off, clean and disinfect. Shields are highly reusable, making them the more affordable choice than continuously buying disposable masks or pricey cloth ones.
It’s also practically impossible to wear them incorrectly, unlike face masks, which many often wear below the nose or leave hanging off their ears. And it’s much easier to speak while wearing a face shield.
More than anything, shields might prove to be a superior alternative for those with certain medical conditions, and for whom face masks might be a danger. This includes those with asthma, allergies, those who are hard of hearing and rely on reading lips, those who are hearing impaired and rely on sound, people of a certain age with respiratory issues, and those living with certain disabilities, including autism and sensory disorders.
Shields are also easy for manufacturers to mass produce, they protect both the eyes and face, and are – despite how they appear – more comfortable than masks when it comes to breathing and general wearability.
These are compelling reasons knowing that face masks aren’t particularly comfortable, they make it difficult to breathe for prolonged periods of time and to communicate, they’re not easy to clean or disinfect, and they require you to touch your face in order to put them on or adjust them.
However, unlike face masks, shields do not provide a seal on all sides of the face, particularly in the case of N95s, which are still prioritized for health-care workers. In the case of a shield, the sides of the face remain open, providing space for particles to move through. That can be ineffective when you have someone behind or at the side of you.
And while we do know that masks – even homemade ones – can protect those around you from viral transmission, there isn’t much research into the efficacy of face shields.
Are face shields the future?
After lockdown measures took effect in March, It took months for face masks to become common sights in Canada. Both the U.S. Centers for Disease Control and Prevention and Public Health Agency of Canada initially said masks weren’t necessary, and now both agencies strongly encourage their use when physical distancing is not possible.
In Toronto, masks are only mandatory in some grocery chains and select stores, though in other parts of the world, including Turkey, Slovakia and the Czech Republic, you can’t step foot outside without one.
Which means it is possible face shields could become the new alternative, but if so, it could take months for public health officials to recommend their use. And a lot more data to prove their effectiveness in preventing viral transmission.
Though, the fact is, no face covering can guarantee 100 per cent efficacy.
“To minimize the medical and economic consequences, it is important to rapidly assess and adopt a containment intervention bundle that drives transmissibility to manageable levels,” reads the JAMA article, which suggests the next step could likely be a combination of physical distancing measures and elevated face-coverings.
“Face shields, which can be quickly and affordably produced and distributed, should be included as part of strategies to safely and significantly reduce transmission in the community setting. Now is the time for adoption of this practical intervention.”
