Surgical-type masks will prevent large droplets from being directly expelled into someone else’s face or onto a surface where someone might be contaminated, but it is pretty clear that the SARS-CoV-2 virus is being transferred by fine droplets or aerosols which can remain suspended in still air for minutes, and any non-respiratory mask (or a respirator mask with an exhaust port, as many industrial-grade N95 masks) is essentially useless to prevent this.
I think the biggest takeaway I get this (and again, it was not a controlled scientific experiment and I am not an authority on infectious disease) is that physical distancing and isolation measures are what is really needed to prevent the spread of the virus. Other measures like washing hands, sterilizing surfaces, and wearing masks may be of some marginal benefit but the only way to significantly reduce infections and shut down the epidemic is to stay at home as much as possible and avoid contact (and by “contact”, that means being in close proximity to another person for a measurable period of time) with anyone outside of your household. All other measures are just essentially feel good efforts that should serve as a reminder of the need for distancing rather than offer confidence that they will prevent infection from contact.
Could you repeat this experiment but this time have a mask-wearing partner near you (within 6 feet) for the 30 sec? Would be interesting to see if the inside of their mask shows fluorescence.
I don’t have anyone to do this with, and I doubt someone else would inhale enough of the exhaled fluorescein to be identifiable (at least, I hope no one is inhaling that much of my breath); if they did, it would be drawn through the mask material anyway. I think you’d have to do some kind of isotope tracing to get meaningful, quantifiable results, and what you would really want to see is how much tracer ends up in their respiratory tract, which is obviously something I’m neither qualified nor set up to do. This was just a casual experiment to see how effectively an improvised mask would do at preventing the spread of small droplets and aerosols, and I think the answer is clearly not very well, although again, the shemagh is a coarse weave that is not really comparable to a surgical mask and a single trial with no control is anecdota, not data.
I’d bet large sums that untrained people would show large amounts of fluorescein at most of the areas that the mask meets the skin.
(And we won’t mention the inherent problem of ‘mask seal’ and facial hair.)
I’m going to post this again. A prospective randomized study showed that surgical masks offered significant protection from respiratory disease to the wearer, as compared to cloth masks and “standard practice” (in the test hospital in Viet Nam, which was predominantly a mix of wearing cloth and surgical masks.)
So… I would guess that a clean cloth mask is better than nothing. But there’s evidence that a surgical mask is better than a cloth mask.
I’ve been wearing a mask whenever I need to go to the grocery. We had a partial box of N95 masks in our garage. An opened box that had not been properly stored and was past its expiration date. They were not suitable for donation but we had enough for everyone in my extended family, with a few spares.
So if you see a “civilian” wearing a N95 mask, don’t assume they are depriving a health care worker.
My observation, based on my grocery run today, is that most people still aren’t wearing them. Most people also still don’t seemed really concerned about the six foot rule. I totally disagree with the theory that the masks make people less careful.
There are people that are taking this very seriously and following all precautions. And there are other people that are being lax about all the precautions, including masks and distancing. This was consistent with my observations in the grocery today.
We were joking around at home and someone suggested that people could just start wearing their underpants on their head. I was bored ( as I am frequently these days ) so I pulled a pair on over my head and fashioned them into a mask using two ponytail bands. Then I photographed it and posted it on FaceBook. I was mostly joking but it looks like a few people at least took it somewhat seriously. I really didn’t know what to think about that.:smack:
I was just showing my wife the paint collection last night, which is where I also store the paint tools. Among the tools was a small collection of N95 masks, surgical masks, and Tamiflu, all labeled in Spanish. The latter of which was long past its expiration, but apparently this was material diverted from the state of Guanajuato during the previous Chinese virus crisis by my ex brother-in-law.
N95 masks with the breathing valve doesn’t really serve the purpose of a general order ot wear masks. Your breath is getting out there so maybe wear a bandana over the mask?
