Vox: “…A lot of these terms are confusing (even to the scientists), and they don’t answer the question laypeople care about: Which air is safe to breathe in during the Covid-19 pandemic, and which air is not safe? To answer that question, it’s helpful to understand two different scientific perspectives on the matter. One is: What physically happens when a sick person breathes, sneezes, or coughs into a room? The other is: What patterns have epidemiologists observed in the way people are exposed to the virus and get sick?…There’s growing theoretical evidence for the airborne spread of the coronavirus. Lab studies, in idealized conditions, also show that the virus can live in an aerosolized form for up to 16 hours (the scientists in this case intentionally created aerosolized droplets with a machine). Another study tracked with lasers the various droplets expelled from a human mouth during speech. It found “normal speech generates airborne droplets that can remain suspended for tens of minutes or longer and are eminently capable of transmitting disease in confined spaces.” Some studies, the WHO reports, have found evidence of the virus’s RNA in the air of hospital rooms, but notes “no studies have found viable virus in air samples,” meaning the virus was either incapable of infecting others or was in very small quantities unlikely to infect others.

What we are trying to say is, well, let’s not worry about whether you call it aerosol or whether you call it a droplet,” Morawska, the co-author of the recent commentary imploring the WHO and others to address airborne transmission of Covid-19, says. “It is in the air,” she says, “and you inhale it. It’s coming from our nose from our mouths. It’s lingering in the air and others can inhale it.”…