In some East Asian countries such as China, Hong Kong and Japan, it’s common to see people walking the streets wearing surgical masks, even without the threat of a global pandemic. However, in places such as the UK, USA, and most of Europe, wearing a face mask in public isn’t usually accepted as a norm unless we’re faced with the threat of infection, such as with the COVID-19 pandemic.
Across Britain, more and more people are beginning to cover their mouth and nose whilst out in public, especially in supermarkets, but do face masks actually protect you from infection?
Who needs to wear a face mask?
According to the world health organisation, throughout this pandemic, you should only need to wear a face mask if:
- You are confirmed to have COVID-19
- You display symptoms or COVID-19 or are suspected to be infected with it
- You care for someone who is suspected or confirmed to be infected with COVID-19
This means that a vast majority of people don’t need to cover their mouth and nose, even when going out in public. However, some people are still choosing to wear surgical masks, respirators, or even homemade masks that cover the nose and mouth.
According to guidance from the WHO, masks are only effective when used in conjunction with thorough and frequent hand-cleansing, something that everybody should be doing regardless of whether they wear a mask or not.
In addition to hand-washing (or hand-cleansing with an alcohol based gel), it’s incredibly important that if you do wear a mask, you know how to apply and remove it in the correct way, as using a mask incorrectly can do more harm than good. You should never touch the front of a mask. Always remove it from behind, and cleanse your hands thoroughly before applying and after removing any kind of facial cover to avoid risking contamination.
Will a face mask protect me?
Surgical masks aren’t recommended for the majority of the population, as there’s no evidence to say whether they will prevent a healthy person from becoming infected with COVID-19, but they can be effective at shielding your mouth and nose from large droplets from somebody that’s coughing or sneezing. However, this is why social distancing measures are in place – so that you shouldn’t come into close contact with an infected person.
Surgical masks are generally loose-fitting and can leave gaps at the side of your face, meaning that they don’t provide much protection against virus particles. However, an N95 respirator mask can filter out 95% of airborne particles, including some viruses.
N95 respirator masks are different to surgical masks that are commonly worn by members of the public. They’re generally more moulded, and form a seal around the face leaving no room for particles to make their way inside. N95 masks can filter out particles as small as 0.3 microns, but even these can’t guarantee immunity from viruses, and like with surgical masks, aren’t recommended to the general public unless you display symptoms of COVID-19, or care for someone that is suspected or confirmed to be infected with it.
Can I use a homemade mask?
With a national shortage of PPE such as surgical masks, respirators, gloves and gowns, supply needs to be focused towards those who need it: front-line healthcare workers that are caring for those with the virus or those that are suspected to have it. Because of this, the public are finding it increasingly more difficult to purchase professional masks, and people are beginning to fashion makeshift covers out of household fabrics.
Whilst this might seem like a good idea, or that it might be better than no protection at all, this isn’t always true. Using a scarf, for example, means that the fabric won’t be able to form a tight seal around your face like an N95 respirator mask, and some fabrics can absorb moisture and encourage bacteria to breed. If you do use a scarf whilst out in public, you should make sure that you take the same cautions that you would with a disposable mask, and remove it from behind. You should also put it through the wash on a hot cycle immediately, then wash your hands thoroughly to stop the spread of viruses or bacteria.
A 2015 study in Vietnam (MacIntyre et al) looked at how efficient cloth masks were versus the traditional surgical masks often worn by people in East Asia. The results showed that cloth masks allowed 97% of particles to penetrate, whilst surgical masks allowed just 44% of particles through, meaning that cloth masks are an ineffective substitute for surgical masks and N95 respirators. However,ef looked at how effective various fabrics were when “challenged with high concentrations of bacterial and viral aerosols”. In this study, a variety of household fabrics were made into surgical-style masks and tested against a regular surgical mask as a control. The average results when faced with both bacterial and viral aerosols are as follows:
Whilst the efficiacy results from the 2013 study by Davies et al showed that the best household fabric to use as a homemade mask would be an unused vacuum cleaner bag, the study also looked at the pressure drop of each makeshift mask. Due to the weight and thickness of vacuum cleaner bags, the makeshift mask ended up being too heavy for use as a face mask, and therefore inefficient as a proper fit couldn’t be ensured.
So should I cover my nose and mouth when I go out?
Whilst wearing a surgical mask or N95 respirator can’t do you any harm, there’s also no evidence to say that it can prevent you from becoming infected with COVID-19. Ultimately, the decision is yours, but as long as you abide by social distancing rules and thorough hand cleansing with soap or gel, it’s unlikely that you’ll contract COVID-19 unless someone in your household is infected.