The possibility of airborne transmission of SARS-CoV2 increases the utility of wearing masks, … [+]
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The Covid-19 coronavirus is not like romance. You don’t want it to be in the air.
More and more evidence, though, suggests that the severe acute respiratory syndrome coronarvirus 2 (SARS-CoV2) can remain floating in the air for a while and potentially travel further than six feet. If you are thinking, “great, now I have to give up breathing,” it’s not that bad. It just means that you should take some additional precautions and avoid certain locations.
Some researchers who study aerosols and air flow have recently been airing concerns that not enough attention has been paid to possible airborne transmission. For example, in a Perspectives article in the journal Science, Kimberly A. Prather and Robert T. Schooley from the University of California, San Diego, and Chia C. Wang from National Sun Yat-sen University in Kaohsiung, Taiwan wrote that “a large proportion of the spread of coronavirus disease 2019 (COVID-19) appears to be occurring through airborne transmission of aerosols produced by asymptomatic individuals during breathing and speaking.” In other words, people who don’t seem to have any symptoms can be contagious and spread the virus into the air by doing silly things like breathing and talking.
Near the beginning of the pandemic, the main concerns being transmitted were the larger respiratory droplets (0.1 to 1000 μm in size) that can come out while coughing and sneezing. These are heavier and thus tend to drop to the ground before traveling more than six feet as you can see in this simulation of a sneeze from Dassault Systèmes:
Note, it is rude to sneeze directly at someone like this, even if that person is wearing a face shield. Don’t expect a “gesundheit” when you sneeze into someone’s face. Regardless, notice how much of the white spray drops the the ground fairly rapidly. This is why many public health officials felt that maintaining a six foot distance was enough to avoid such a spray, assuming that people don’t jump forward while sneezing or coughing.
However, at the same time, watch how some of the colored spray that goes more airborne and floats off towards the right upper hand corner of the screen. It is the airborne particles, the ones that are smaller (5 μm or less) that could possibly travel further and potentially hang in the air for much longer periods of time. In fact, as I have covered previously for Forbes, you don’t even have to sneeze or cough to expel these smaller particles. Even simply talking and breathing may expel such particles, especially if you use the “th” sounds as in saying “shake that thang.” Of course, just because you find viruses hanging in the air doesn’t necessarily mean that there is enough of them around to get you infected. However, the more you say “shake that thang,” the more things could add up to create more of a mist.
In a publication in Environment International , Lidia Morawska from the Queensland University of Technology and Junji Cao from the Key Lab of Aerosol Chemistry & Physics (KLACP) at the Chinese Academy of Sciences argued that it is “extremely important” that “national authorities acknowledge the reality that the virus spreads through air, and recommend that adequate control measures be implemented to prevent further spread of the SARS-CoV-2 virus, in particularly removal of the virus-laden droplets from indoor air by ventilation.”
Why is this lingering possibility now a distinct possibility? Well, the original SARS virus seemed to spread through the air, based on studies what occurred in the Prince of Wales Hospital in Hong Kong, health care facilities in Toronto, Canada, and an airplane during the 2002-2003 SARS outbreak. This raised the question of whether air travel runs in the family, meaning this SARS-y family. Indeed, a study that was published as a research letter in the New England Journal in March did show that SARS-CoV-2 could survive in the air for three hours, leaving everything still up in the air.
Scientists continued to wonder about the airborne possibility as more and more reports suggested that the SARS-CoV2 has been spreading much more readily than the flu, which, incidentally is not the same as the Covid-19 coronavirus. For example, the virus has seemed to run through cruise ships faster than a smear rumor spreads in a high school or an academic department. Even those who didn’t seem to come into close contact with others caught the virus. A recent publication in the Centers for Disease Control and Prevention’s (CDC’s) Morbidity and Mortality Weekly Report (MMWR) sang a different tune from the original thinking about SARS-CoV2 as well. It detailed how 52 out of 61 attendees of a two-and-half-hour-choir practice subsequently became ill with Covid-19 with three eventually being hospitalized and two dying. Unless, it’s some kind of extreme or mixed martial arts choir practice, such activities don’t tend to involve everyone coming into close contact with each other or holding the same items.
Additionally, some have wondered whether the more extensive mask use in Taiwan and South Korea has helped these countries better control the airborne spread of the virus than the U.S. has. Of course, mask use certainly isn’t the only thing that the Taiwanese and South Korean governments did differently from the U.S. government. For example, they didn’t seem to mention the possibility of injecting disinfectants.
What’s really needed are more air sampling studies that can detect the presence in different locations and air flow situations and then determine if enough virus is present in each case to infect people. Such studies are easy said than done though, since there aren’t simple ways to test the air for SARS-CoV2. Having someone run around face first and inhaling deeply to then see if he or she gets infected is not an appropriate way to test for the presence of the virus.
So, assuming that don’t want to hold your breath all of the time, what does all of this mean when it comes to protecting yourself? Well, for now, you probably want to beware of the following places:
1. Enclosed locations where people are not wearing masks.
Yes, you could always opt for indoor locations where people are not talking or breathing. But such a place could be creepy and have terrible service. The threat of airborne transmission means that staying six feet apart from others may not be enough. It’s still not clear how far the viruses may travel and still be able to infect people. Some are saying 12 feet (which would be about two Denzel Washingtons, assuming that Washington is six feet tall). Others have mentioned 20 feet (3.33 Denzels) or even 27 feet (4.5 Denzels). Making sure that everyone stays at least 4.5 Denzels away from you at all times is not very practical, unless you smell really bad and are willing to shout your credit card number to the check-out person.
Therefore, masks are the best available way to keep people from expelling viruses in the first place. Growing concerns about airborne transmission is why public health experts have moved towards recommending that people wear masks in indoor locations when they may come closer to others.
Therefore, before you enter any enclosed space, take a peek at what people are wearing on their faces and what they are doing to protect you from them. As I have described before for Forbes, wearing masks is not about suppressing freedoms or making people less masculine. For example, The Liberty Tree Tavern in Elgin, Texas, has taken this refusing to wear masks thing to a whole another level, actually banning its customers from wearing face coverings, as this CBS47 segment shows:
When no one is wearing masks in a tavern, freedom may not be what’s in the air.
2. Small enclosed locations.
Here is a situation where size does matter. If the virus can hang in the air, places that don’t have as much airspace may have higher concentrations of the virus. Look at not just the width and length of the room but also the height.
3. Areas that seem musty, stale, stuffy, or any other sign that the air is not moving.
“This smells like yesteryear” may be great for memories but not for air flow. you should always sniff out a joint before using it. That applies to bars, restaurants, stores, and other business establishments too. If you can smell the “Scent of the Douchebag” cologne that the person all the way on the other side of the room is wearing, then you may be breathing in others things that the person may be emitting.
4. Indoor locations that do not circulate fresh air.
Simply blowing around dirty air may be just blowing it. That can be like using a dirty towel to wipe yourself. It’s still not clear how well the SARS-CoV2 can travel through and survive in different ventilation systems. More studies are needed. Nonetheless, it’s probably safer to have a ventilation system that actually exchanges old air with fresh air, either from the outside or by filtering the air.
5. Locations where many people hang out for a while talking, singing, or panting.
As I have indicated before for Forbes, in general, you probably want to avoid a place where many people are panting for a long time. The same goes for moaning. With the Covid-19 coronavirus around, though, there should be extra incentive to stay from any place where a bunch of people are doing anything for a long time. Such lingering raises the risk that the air has something else lingering: floating virus particles. Some restaurants are moving towards outdoors seating to reduce this risk. After all the great outdoors has a gigantic ventilation system known as the wind. The risk outside is certainly not zero but the viruses are probably more likely to be blown away and less likely to remain concentrated in one location.
All of this is a reminder that health is not just about your body. It’s also about the systems around your body, including the air flow and ventilation systems. And, in this case, ventilation doesn’t just mean wearing boxers instead of briefs. There is a need to have more mergers and crossovers among historically separate fields such as flow dynamics, microbiology, infectious diseases, and sociology. Without more such circulation, knowledge could end up stagnating.