Thread by @nCoVPerspectiv1

* FACE MASKS - A THREAD *

There's conflicting views about face masks in relation to Coronavirus. We've attempted to gather publicly available information & apply common sense. The following is our take, and is provided 'as-is'. You must make your own health decisions.

#COVID19

2. There are two common styles of face masks which most people consider - surgical masks and respirator masks (e.g N95)...

3. The surgical type are paradoxically the more basic, and the type you often see in hospitals. They are designed primarily to prevent you infecting others, & can reduce large droplets or fluids hitting your face. They are *not* designed to filter air entering your mouth or nose.

4. The respirator type are designed to create an airtight (or near airtight) seal around your mouth and nose, and filter the incoming air of particles. They typically have a soft metal band that is moulded by you, around your nose, to help create an airtight seal.

5. Both types should provide *some* degree of virus protection, but the details are important. The goal of this thread is to provide info on some of the practical considerations, to help you understand masks better. Read all instructions from your mask manufacturer before use.

6. Nobody knows exactly how #coronavirus spreads. It is widely assumed it can spread via droplets, ejected from coughs, talking or breathing, and the virus within such droplets can stay alive in air or on surfaces, and these can enter your body through the mouth, nose or eyes.

7. Another possibility is that the virus may be ejected through feces, and possibly urine. If this is the case, anything that 'aerosolizes' such matter, and where it lands, is of concern. As an example, diarrhea would be a reasonable concern, or urination 'splashes'.

8. We feel it is prudent to constantly think in logical terms about how the tiniest of droplets, from any of the above sources, might in some way get into your eyes, mouth or nose - either directly or indirectly. If you constantly think this way, you can make better decisions.

9. For example, putting your phone down on a table, near where someone previously coughed, that you then press against against your face, might transfer the virus to you. Touching anything in a public restroom, including the door handle. Being in close proximity to people.

10. If someone coughs in your direction, both surgical masks & respirator masks will provide some element of protection from physical (larger) droplets directly hitting your face, but surgical masks may *not* protect you from 'airborne' particles. What are airborne particles? ...

11. Airborne transmission is where extremely tiny particles - think dust size, stay aloft in the air, and do not fall to the ground quickly via gravity. We've all seen dust in sunlight. It's easy to imagine how this might be breathed in through the 'open' sides of a surgical mask

12. Airborne transmission has not been proven for contracting #COVID19 but it would be prudent to consider it likely. Many experts believe it is the case for flu. Incidentally, we feel 'air-tight' goggles such as swimming goggles might be just as important as air-tight masks.

13. If someone coughs towards you from side-on, droplets might fly past the open sides of a surgical mask. All of the foregoing demonstrate why a close-fitting N95 respirator mask would likely provide more protection than a surgical mask, assuming it is fitted & used correctly.

14. This last point is important. An N95 mask that is not tightly fit, is little different to a surgical mask (but likely better than no mask). So when people say "masks need to be fitted" this is what they mean. Beards will break the seal, the metal strip needs to be shaped, etc

15. If you wear an N95 mask correctly, you should get a benefit over a surgical mask. But with any mask, you should assume the outside of the mask has virus on it, when you take it off. If someone sneezes towards you, it lands on the mask. So how you take it off is v. important.

16. Nearly everyone instinctively grabs the front of a mask and pulls it over their head to remove it. This is very bad. The virus is likely now on your hands, and it is human instinct to rub your face to relieve 'mask itch'. But doing so would likely infect you. Do not do this!

17. 3M recommends holding the straps to remove. We think scrub your hands, and dispose of it as if it's a biohazard. It goes without saying you should not wear a disposable mask a 2nd time. Again, consider the mask, and any other PPE gear, after wearing, has the virus all over it

18. In summary, face masks provide 3 primary benefits, when used correctly:

1. They help prevent you spreading infection to others

2. They help protect you from (at minimum) large droplet transmission

3. They inhibit you from touching your face

#COVID19 #COVID19UK

19. There is a trend at present for a counter theory that face masks provide little or no benefit. Our research suggests this is not the case. It is possible this rationale emerged from people who are concerned about mask availability for health care workers.

20. We must all judge our own risk tolerance & social responsibility. If there were no mask shortage, there would be little reason not to recommend everyone having them, finance permitting. There is a global shortage however, & healthcare workers arguably need them more than most

21. As suggested at the beginning, we must all make our own decisions about how to protect ourselves & those around us. Saying that masks provide no benefit is possibly dangerous advice, and should be questioned. Thank you for reading. Please take care. /END