Saw this and debated posting it, but didn't, as I thought it was overdone. This is exactly the kind of research that chem engineers do and it's certainly cool/interesting stuff, but I think it's worst case kind of thinking. Yeah, maybe there are rare sneezes that can go well beyond a 3-pointer, but most people don't sneeze "outward" and I doubt more than a few sneezes are that powerful and to suggest that the virus becomes truly airborne (virus droplets small/light enough to remain aerosolized for hours and infecting people who walk through the wake of a sneeze 2 hours later or 100 feet away via HVAC) strains credulity.
In addition, we still don't know the dose-infection response curve for this virus, meaning we don't know if people 5' or 20' away from a sneeze would become infected from those virus-laden droplets, much like we don't know if touching a few day-old dried up virus particles on a surface can cause actual infection. It's also been well documented that about 80% of infections in China and elsewhere come from close contact in the home and if the virus was truly airborne and infectious at great distances from sneezes/coughs, we'd very likely see far greater transmission rates than we're seeing. Doesn't mean people shouldn't try to control their sneezes/coughs (mask anyone?), though or that health care workers shouldn't wear the appropriate PPE around symptomatic patients, in particular, but I don't think we need to be changing the 6-foot rule yet.
https://rutgers.forums.rivals.com/t...entions-and-more.191275/page-125#post-4571736
Excellent article in NatGeo on the question of whether the virus remains airborne as aerosolized fine particulates (<5 micron virus-laden droplets, as larger ones very likely fall to the ground very quickly via gravity) and even if they do, whether they remain suspended and viable for extended periods and whether they truly end up infecting others more than 6 feet away via ventilation systems or just from being in the area, since we know the "dose makes the poison," i.e., the viral dose is hugely important in whether someone gets infected (even though we have no controlled studies on that, which would be unethical).
I've been very skeptical of this route of infection being more than negligible (post above), because the amounts of viable viruses ever collected far away are tiny, especially relative to the numbers of viral particles actively shed by an infected person onto that person's body and exhaled and/or discharged, via sneezes/coughs, which is why the vast majority of cases traced by epidemiological studies have been from close contact. I also look at it this way: if HVAC were a serious source of transmission, far, far more people would be infected by now (same thing for surfaces, by the way). It doesn't mean it can't happen, but I think people are way overworrying about this route, especially since wearing a mask will very likely take that risk down to essentially zero (2nd post above).
https://www.nationalgeographic.com/...20200814&rid=3F7A7D00850AD922736B3173646A296D
The article does a nice job of going through the cases for and against aerosolization as a major route of infection, but to me it leans towards that only being a minor transmission pathway, but hedges by saying the usual things: since we can't be 100% sure, wear a mask/practice distancing and stay out of crowded indoor spaces in particular.
But in all of these case studies, aerosol transport did not happen over long distances, which bucks one of the classic conditions for airborne transmission. Chickenpox, for example, is thought to spread down long hallways or across windows of adjacent rooms. Measles can infect people for two hours after someone with the disease leaves a room.
So if coronavirus is airborne, why doesn’t it behave like chickenpox or measles? Compared to most other respiratory diseases, measles is thought to require very little virus from one person to seed an infection in another, and people with measles likely spew enormous amounts.
“Measles is the champion. It’s the Mohammad Ali of viruses,” says Jorge Salinas, hospital epidemiologist at the University of Iowa’s Carver College of Medicine.
The SARS-CoV-2 coronavirus, on the other hand, may require inhaling a much higher dose to seed a new case. This may mean that coronavirus mist needs sufficient time to become more concentrated and therefore more hazardous—though a modeling study published on July 27 reported that few people with mild or moderate symptoms would produce a high enough amount of virus to pose a risk in poorly ventilated places if breathing normally. The risk increases with coughing.