The 5 ways face masks work even though the virus is small enough to pass through them

Face masks work even though the virus is small enough to pass through them. Here are five reasons why.

1) The fabric slows down the virus, even though it is small enough to pass through them, Just like the barriers in the picture below.

Slowing down the virus is important, for it reduces the distance it might travel. A sneeze that would have hit a person one-meter away doesn’t anymore, if the sneezer wears a mask. It’s like extra social distancing.

2) The fabric captures the virus. Even though a large portion of the virus gets through the mask, part of it sticks to the fabric. This effect is particularly strong in N95 masks, whose fabric is electrostatically-charged, but is also present in common surgical masks.

3) Even a small reduction in the virus that passes through matters. If there is a superspreader in a bus, and thanks to face masks only 9 passengers get infected instead of 10, that 10% difference might result in hundreds of lives saved, once you consider that one person can infect dozens. The effect of masks compounds (more on this later).

Moreover, if the hypothesis that infection severity depends on viral load proves correct, even a 10% reduction in the amount of the virus that passes through could become the difference between life and death.

4) Masks are not (just) for preventing the virus in the air from reaching your nose. They are for preventing the virus from getting in the air in the first place. This is useful to reduce the viral load in the air we respire.

5) Even badly-fitted masks work. Because, as previously mentioned, even partial protection is better than none, and the effects compound.

The compounding effect of masks

Masks can have a powerful protective effect on a population even though their protective effect on a single person is limited.

Suppose that on day 0 we have 100 infected in a country, and one month later, they became 100 thousand. It is easy to understand how even a reduction of 1% of infected on day 0 could have meant a thousand less infected a month later (more or less). Infections compound, and so does protective equipment.

Moreover, suppose that the hypothesis that infection severity depends on viral load proves correct. If, thanks to face masks, those 100 infected at day 0 can only throw in the air 99% of the virus they would otherwise expire, it might mean that their “infective power” is reduced. Perhaps, after one month, we would only have 90 thousand infected, and their infection would be less severe (so, fewer deaths).

Bad arguments against face masks

Over the last few months, I’ve heard terrible arguments against face masks. Here are a few.

1) The second wave shows that masks don’t work. By this reasoning, brakes don’t work because all cars have them, and yet a lot crash.

2) I know of this Randomized Controlled Trial (RCT) study that shows that masks do not work. Many studies I know of are conducted on doctors wearing masks in the presence of patients not wearing them. These do not show that masks don’t work. They just show that masks are not fully effective for personal protection – but again, as written in the first part of this essay, masks are about partial protection that compounds at the population level.

Moreover, all studies I know of concluding that masks do not work have been made in hospital settings. In hospitals, slowing down the virus doesn’t matter much, for doctors and patients are exposed for hours to each other. Conversely, slowing down the virus is extremely effective on a bus or in a shop, where exposure is short-termed.

2) There is no evidence showing that they work. There is no thorough study because good luck organizing a long-term population-wide one in which everyone wears the face-mask. As mentioned above, these three conditions are non-negotiable because they are where masks are the most effective.

Moreover, wearing masks is a low-downside high-upside behavior, whereas not wearing them is a low-upside high-downside one. Therefore, we should wear them until proven that they are dangerous or ineffective, not the other way around.

3) Mask compliance is not 100%. So what? Even if not all drivers are sober, sobriety at the wheel should still be encouraged.

4) Masks cause CO2 buildup. Carbon dioxide is much smaller than viruses. If you believe that the virus passes through, you cannot believe that CO2 cannot.

Moreover, some doctors have been wearing them hours straight for years, with no known negative repercussions.

5) Masks are hazards because people touch them while taking them off and get contaminated. Perhaps, but the virus that landed on the face mask would have landed on the nose or mouth, if the mask hadn’t been there. Hardly a better outcome. Moreover, the same problem applies to glasses and phones. But I never heard anyone saying that people shouldn’t use glasses because they are a contamination hazard.

6) My friend always wears face-masks, and yet he got sick. I also know someone who drove carefully and yet got hit by a reckless driver. Your friend probably got sick because someone else wasn’t wearing face-masks. (or he got it at the restaurant, etc.)

Conclusions

Face masks are effective even if they are not perfect.

They are the most cost-effective measure we have to fight COVID, and it would be stupid not to use it.

(By the way, I’ve recently published a book on Ergodicity, in which I also discuss how the failure to understand ergodicity affected us during the COVID pandemic.)