The fatal flaw with this study seems to be that it repeats the 1990s Seattle study with the control group being “bicyclist that crashed” and not “bicyclists”. From the link
" A total of 43 studies met inclusion criteria and 40 studies were included in the meta-analysis with data from over 64 000 injured cyclists.** For cyclists involved in a crash or fall**, helmet use was associated with odds reductions for head injuries"
It doesn’t say if helmets reduce head injuries for bicyclist as a whole, including those the did not crash, due to risk compensation or the proven deterrent effect on helmets for bicycling which makes bicycling more dangerous because motorists are less used to seeing them. And of course it doesn’t’ address the problems with lack of exercise that helmets exuberance because people won’t go bicycling if they are required of feel they have to wear a helmet.
Any COVID mask study is going to have to look at the population as a whole, not just those that wear masks. As I’ve stated before I would not feel safe going out with only a cloth mask so I’m not going out until N95 masks are available, but others may go out and expose themselves with a mask when they wouldn’t otherwise.
Disclosure: I wear a mask whenever I go out. Even if the efficacy is only 20-25%, it is well worth the effort.
However, when I go to the store I frequently see people who are NOT wearing masks. (And many of them are crowding around me to reach things on the shelves.) Surprisingly, many of them are young mothers with toddlers. Now, when I see these people without masks, I think it’s fair to assume that they are just as slack about personal protection in other areas. Maybe they have children’s play groups, or visit places where COVID-19 is more common (nursing homes, etc). This may be an unfair assumption, but I’m inclined to be very cautious around them. If they’re obviously not concerned about reducing exposure in the store, why would they be significantly more concerned about protecting themselves in other environments? I keep extra distance between us.
Not a huge problem - they can be easily made and worn by pretty much anyone. The purpose of wearing a mask is not to protect the individual but rather to protect the public by preventing or greatly reducing the spread of droplets. It’s the easiest thing to do as a ‘herd’ to protect ourselves. Without a vaccine, next to staying indoors and self-isolating, it’s probably the best we can do for the time being.
Again, the number one reason to wear a mask is to help reduce the spread of air droplets that you exhale. Data in countries where mask use was adopted very early in the pandemic seem to reinforce the case for wearing masks.
I agree that everyone has to buy in to the necessity of wearing them, and that is one of many problems. Too many of us are angling for a way to have the public health response accommodate our individual freedom to move and associate, and to carve out a space to promote economic recovery. But that’s not going to work.
If each person wears a mask, they’re reducing the numbers of droplets in the air. Even if someone gets exposed, they’re exposed to a smaller dosage of the virus, which makes it slightly less dangerous. Virus contagion comes down to a lot of basic math. Having everyone cooperate by wearing masks protects the herd. It doesn’t make us immune, but it reduces the numbers of people who get sick. It reduces the severity of the illnesses. It allows healthcare workers to give patients more attention. It makes the work environment of first responders safer because there are fewer COVID-19 patients. Wearing a mask isn’t about you or me; it’s about all of us.
I can’t get over how many people here are stubbornly refusing to do very basic things to protect not just themselves but others.
I think you’d have to look at how well those masks were worn to compare the benefit to America. In those countries, did people do things like have their nose sicking out of the top of the mask, pull down the mask to talk to people in the store, wear masks of tightly stretched t-shirt material, and so on? Did they use a hand to hold a rumpled up cloth to their face as a mask. Did they act like the mask gave them 100% protection so they could ignore social distance guidelines? That’s the kind of stuff I see regularly in public. If the citizens in other countries were properly wearing surgical masks and better, we shouldn’t directly apply the benefit they saw with masks to Americans wearing masks.
Funny you should pick that number. I know that you picked it because it looked absurdly low, but the actual effectiveness of the Mumps part of the MMR inoculation is only about 60% for an individual, but yet it works across society as a whole, and, excepting a few antivax nutjobs, is accepted as working across society. Shows how effective herd immunity is. If only we can convince everyone that even 60% effective, if used across the entire population, is very effective.
There are not enough of those masks to go around and the should be reserved for our health care professionals.
If we as a society wait until everyone has a supply of those types of masks, and there is a vaccine and mass testing, we will have waited to long to reopen commerce.
The threshold of no one transmitting the virus and zero deaths is too low.
There was a relevant article in The Atlantic last month. It emphasized that cloth masks are not for your own protection, but the protection of others. However, that protection may be better than most people realize.
Money quote:
“Models show that if 80 percent of people wear masks that are 60 percent effective, easily achievable with cloth, we can get to an effective R0 of less than one. That’s enough to halt the spread of the disease.”
I stand by the statement that there’s no safe way to go back to an office workplace.
Yes, we can mitigate the risk and reduce the infections.
Yes, we can do things to keep the curve flattened.
But it is absolutely 100% false and irresponsible to say that it’s safe to open everything back up and resume life as usual now. The reality is that though it’s no longer getting worse (in most places), it’s just about as bad as it ever was.
The only reason we’re having seriously reopening decisions is that all of us (I think) understand that the economy and workers cannot withstand an indefinite prolonged shutdown. A total shutdown definitely would stop the pandemic, but in reality, different people and systems will reach their respective breaking points as shutdowns remain in effect.
This means that leaders are making decisions on the best way to permit (or coerce) people back to work to limit the economic damage, with differing levels of sensitivity to worker safety. In some cases we have clear guidelines as to mitigate risk, in other cases businesses are asking for exemption to liability from lawsuits. Whatever strategy is being employed, they all recognize that it isn’t yet safe for people to share workplaces as they used to.
Even if we had an adequate supply of N95 respirators or surgical masks made with qualified ASTM F2100 materials, many people would not wear them properly, e.g. not fitted, the mask covering the mouth but not the nose, excessive facial hair, handling and adjusting the mask frequently, et cetera.
I’m not sure how effectiveness of the mask in ranked in terms of reducing transmission butby that chart if everybody wore masks that were 40% effective R[SUB]0[/SUB] would be less than 1, which seems unlikely given an unmodified R[SUB]0[/SUB] between 3.8 and 8.9.
As an upgrade to my experiment in [POST=22230904]this post[/POST] I recently ran a similar experiment with a professionally-made fitted fabric mask with a dual thickness nonwoven spunbond polypropylene filter element (not the nanofiber melt-blown PP used in surgical and N95 masks but a droplet-impermeable fabric used in medical gowns and dental bibs). I’ve been meaning to write this up in more detail but essentially while there was some modest improvement in emission through the filter elements themselves, aerosolized fluorescein dye still escaped the mask and covered the forehead, neck, ears, shirt, and hands. While any face covering will prevent violently exhaled sputum from traveling many feet as a violent cough or sneeze will do, from what I observed it does little to attenuate the exhalation of aerosols even with a filtering element (again, not surgical mask or respirator grade) because the aerosols can escape through or around fabric areas. The potential for a mask saturated with breath containing virions or other pathogens to produce aerosols due to the user exhaling and forcing tiny droplets to be released on the front side of the mask exists, although this is still probably less than the viral load an infected person’s breath may contain
There are still good reasons to wear a mask, insofar as it signals the wearer’s understanding of the epidemic, it prevents users from putting fingers in their mouth or nose (although eyes are still exposed mucosal tissues that could accept virus), and may instill some discipline in handwashing and other hygiene measures if people are educated. But it should be well understood that wearing a non-respirator mask, or wearing a respirator mask that is not correctly fitted or handled, is not a substitute for physical distancing outside the household and other hygiene measures.
Unfortunately this seems to fall under the behavior response of oppositional defiance, and thus, is not really subject to an appeal of rationality or compassion. It is understandable that people who have lost employment or own businesses that are shuttered are resistant because they are placed into a precarious position, but the people refusing to wear face coverings or follow other easily adopted distancing measures are doing so just because they don’t feel like it or because it offends their sensibilities.
This is analogous to the opposition to wearing seatbelts in automobiles once they were standardized; it took a generation of public information campaigns before people were regularly wearing seatbelts despite the obvious potential to reduce a fatal accident to a much less severe outcome and there is virtually no downside to doing so. And wearing a seatbelt is something that directly benefits the wearer; following isolation guidelines is about the benefit to the population as a whole in limiting the spread of the contagion, and it seems like a lot of people look upon such measures from the lens of “What does this do for me?” and decide to do whatever they please unless forced or shamed into doing so.
Which supports Riemann’s point in a broader way … the biggest benefit in public contact circumstances is in maintaining 6 feet or more distance to a very great degree.
What you describe is that someone not wearing a mask may be more likely to have others keep farther away from them, which lowers their risk much more than a mask would. And, he posits, wearing a mask may give a false sense of security, resulting in more time spent within others’ greater risk six foot circles.
The point is that the benefit of all wearing masks if all else stays the same can be easily swamped by what does not stay the same when masks are worn, if they result in less safe behaviors by the individual or those around the individual.
It is a good point but I am not convinced it is true.
We are socially conforming creatures. A large portion of others wearing masks signals that the norm is to take protection from exposure seriously, that people around you care, that you would be negatively judged for behaviors that signal you do not take it seriously, and encourages others to conform with that attitude and the behaviors consistent with it. A large portion not wearing masks sends the opposite message and has the opposite impact.
My WAG would be the conforming benefits of that social signaling outweigh any potential risk compensation. Beyond risk reduction it sends a message to others that you minimally respect their anxiety and concerns. Not wearing a mask around those who are wearing them is a bit like smoking in an enclosed space with those who you know object to it: minimally it is just being a jerk.
Masks when more than the very briefest contact within 6 feet in public is expected as moderately likely are a low cost intervention. Despite Riemann’s well made point, their risk of negative impacts is minimal. There should be no rush to pull back from low cost interventions of likely little negative impact.
Have you done that experiment with a surgical mask? If so, one variation I’d be really interested in seeing is using first aid tape to seal the edges of the surgical mask to your face to prevent anything from escaping along the edges. When I wear a surgical mask, I can feel the air escaping along my cheeks from the gaps.
This is the argument that the federal health ‘experts’ made against wearing masks in public, but there’s no reason not to wear a mask - none at all. It’s obviously better if people can wear the mask properly, and use the right size, and so forth, but wearing masks is for everyone’s benefit. Some people wear them incorrectly; most I have seen wear it the right way. The only danger from encouraging masks is a false sense of security, but that can be addressed with sufficient public awareness.
Anecdotally, one of the main problems I’ve observed is that it’s so much more difficult to conduct a conversation when masked. Without masks, it’s pretty easy to talk to somebody from 10 feet away. With masks, that’s impossible, so you’re either lifting your mask to speak or approaching closer together. A real-world test of transmission risk would not be just with/without a mask at the same distance, it would consider the realistic need to communicate with and without a mask.
As for psychological effects - supermarkets are probably one of the principal hotspots for spread while we’re generally in lockdown, and I always watch people’s behavior, employees in particular. Numerous times over the past few weeks I’ve had employees approach close to me at the self checkout “to help”, and when I’ve challenged them and asked them to maintain 6-foot separation, the response has always been “but I’m wearing a mask”. Most supermarkets are counting people in and out of the store, and at more than one location they have an employee standing in a doorway that’s maybe 4 feet wide. When challenged to stand further back? “But I’m wearing a mask”.
Contrary to your assumption, pretty much every time I venture out that I observe people apparently (or even explicitly) engaging in riskier behavior because of masks. I’m not suggesting that we stop wearing masks, but I think we need much stronger guidance and training to try to stop this risk compensation. It’s not easy to judge. On the one hand you want to convince people that there’s a good reason to wear masks. On the other hand, you want to tell them that the amount of protection they are getting may be so minimal that they should act just as they would without a mask.
But bear in mind that the issue that needs to be factored in here is that the most physically protective mask will almost certainly not be the best mask in practice. An effective mask will be something that people are comfortable wearing for long periods without frequently touching and moving, and through which (where applicable) they can communicate from a suitable distance.
My wife just returned from a run to several stores. As usual, she was wearing a mask and gloves. (She also takes a shower as soon as she gets home and washes her clothes.)
She was a bit distressed to find that the cashier at the grocery store was wearing her mask well below her nose and was wiping her nose with her ungloved hand as she moved my wife’s purchases through the scanner. My wife pointed this out to her in a reasonably polite way and the cashier basically threw a hissy-fit. The manager had to get involved. All my wife wanted was for the cashier to wear the mask properly, per the store’s policy, and stop touching her snotty nose while handling the groceries.
Trust me, my wife is a very courteous person, so I really do believe that it was brought up in a polite manner.
Totally agree. I’m the type who favors efficiency over comfort. I tape my surgical mask to my face so that it seals better and I don’t have to worry about it moving around. I also wear my P100 respirator when I go grocery shopping because I can relax when I have that level of protection in that close environment.
People can tweak their mask depending on their situation. When walking along a trail, a simple mask may be fine. But when someone is going to be in a crowded situation for a long time–like in an office, airplane, etc–then the person should be more worried about effectiveness over comfort. Making your mask more comfortable on a trail may not really change your chances very much, but it could make a big difference on a 3-hour flight.
But yeah. We are in world in which people get violent over being asked to wear a mask, getting hissy over being told they are doing it wrong doesn’t surprise.