The first thing one notices is that instead of a few East Asian tourists protecting themselves against the poor air quality of megalopolises, at least a third of those traveling were wearing masks. Some unknown percentage of these travelers presumably have sound, medically-directed reasons for donning the masks (e.g. they have some sort of infection, they have compromised immune systems, etc.) but for many they are merely a security blanket. I suspect the reason that "wear masks" isn't a part of the advice of public health experts has to do with the two types of masks that one sees:
First, the type that are to keeping out virus as a chain-link fence is to keeping out mosquitos.
Second, the type that will keep out virus (if worn / changed as directed,) but which - because they are expensive and hard to come by - are worn far too long, such that they become a nice warm, moist petri-dish pressed up against one's face.
I don't begrudge anyone a security blanket. In fact, a lot of what I'm suggesting herein are ways to maintain a confident and positive attitude so your immune system can be its awesome self - whatever that takes. My worry about the mask phenomena is that some people seem to believe that if one little viral agent makes it inside their body they are doomed. That's simply not the case. If a viral marauder gets into your body, its chances of being escorted right back out by your body's mucosal bouncers, swallowed whole by a macrophage, dissolved in your stomach's acid bath, or otherwise being discovered and destroyed by your body's sentry force is quite good.
In short, a mask isn't your last line of defense. It's a first line of defense that's followed by an immune response that is swift and deadly to foreign invaders. It should be noted that nose-breathers already have a kind of mask, in the form of the nose and nasal passages. When you breath through your nose, your natural filtration system is at work. If you tend to breath through your mouth (particularly during inhalation) you have a lessened defense.
If you have trouble maintaining nose-breathing under all circumstances, I'd recommend a pranayama (yogic breathing exercises) practice. I don't know how well it's established by study, but I've found that I breath much more effectively and consistently through my nose since I've regularly practiced pranayama. Another helpful yogic tool is kechari mudra, which has helped me to even run without mouth breathing. (Kechari mudra involves curling the tongue so that the bottom of the tongue rests against the soft palate at the back of the roof of one's mouth. This seems to reduce turbulence that would be created by air swirling in one's oral cavity, and makes more of a direct line of travel for the breath in and out through the nasal passageways. At a minimum, it focuses one's attention on the area the breath is passing through, and makes one aware of the breath.)
All this talk about one's immune system keeping one safe may seem a bit pollyannaish or over-optimistic. Don't get me wrong, I follow and would recommend others follow all the basic precautions regarding washing one's hands and minimizing hanging out in high density environments - particularly high density environments with high-risk individuals. (i.e. for the asymptomatic [or alternatively-symptomatic individuals, i.e. those who have something but probably not COVID-19] who think they absolutely must be tested to have peace of mind, realize that you are likely walking into a high-risk environment and increasing your chance of self-fulfilling prophecy. Just sayin'. If you are able to rest comfortably, you might want to consider doing so.)
Back to the issue of being irrationally optimistic or a Pollyanna. My response is: fair enough. But there is an upside to being overly optimistic (if cautious) but none-whatsoever to being a worrier. Again, by being "a worrier" I'm not talking about taking precautions, I'm talking about obsessing or being needlessly pessimistic about the bodily systems (e.g. your immune system, your lymphatic system, your digestive system, etc.) that are keeping you safe all day and everyday.
I'd say if there is an upside to the pandemic, it was in reminding me to practice gratitude toward my body, my immune system, my gut bacteria, etc. - all of which keep me feeling excellent 99.9% percent of the time. Does that mean I think I can't catch infection? No, it doesn't, but it does mean that if I catch one my body will be much more effective at defending itself.
So when people ask me why I'm not worried about traveling, it's because my immune system is awesome and I'm thankful for it every day.
A couple of post-scripts:
- I've been seeing the swarm of memes about toilet paper shortage in the US. Having moved to a part of the world that recognizes that wiping one's backside with dry paper isn't the height of sanitary practice, all I can say is: "You might want to look into what most of the world does most of the time."
- I understand that there is a desire to curtail a wider spread of the virus, but this easily tips into a form of xenophobia - "a your COVID-19 is worse than our COVID-19." If a person is without symptoms, being Chinese (or from any other country with many cases) doesn't mean that they are Typhoid Mary.