Months into the coronavirus pandemic, researchers are finally getting a better handle on how the virus spreads. Yes, it can be transmitted on surfaces, but the primary source of new infections is close, person-to-person contact.
And there is also growing consensus among experts that being outdoors is less risky than being inside.
“It is safer,” said Kimberly Prather, a professor of atmospheric chemistry with Scripps Institution of Oceanography in California who is an expert in aerosols. Prather told HuffPost that air and wind can quickly dilute the virus.
But they’re not magic.
So if you’re heading outdoors, here are some safety steps experts say you should still take.
Wear a mask.
Mask wearing has become woefully tied up in politics, but there is mounting research showing it’s one major way to help halt the spread of Covid-19. Even researchers who say that the current data is somewhat limited still say that wearing a mask is a good idea.
That’s because of how the virus spreads.
It passes from one person to the next through respiratory droplets that are not only released when a person coughs or sneezes, but also when they talk or breathe — which means you cannot stay healthy simply by steering clear of people who seem obviously unwell. (Also, while there is no clear consensus on how common asymptomatic spread is, estimates suggest anywhere between 40% and 80% of cases are mild or symptom-free.)
Many experts, including Prather, also now believe that Covid-19 can be transmitted via aerosols — basically, really tiny particles that can hang in the air for some time. For that reason, Prather has been beating the “wear masks” drum for months now, and recently published a piece in the journal Science that argued for universal masking.
“What people have missed for a long time, and now it seems to finally be catching on, is that when you have big drops from a cough or sneeze — or when people are talking, or singing, or breathing, you produce aerosols, and those don’t settle to the ground in 6 feet,” Prather said. Instead, aerosols can build up in the air and last there for hours.
The good news is that aerosols and other respiratory droplets are diluted much faster outdoors. And most viruses can also be inactivated in sunlight, Prather wrote in her paper. But there are no guarantees — especially with a virus about which so little is known ― and she has called for more studies examining what, exactly, happens to the coronavirus outdoors.
That’s why, for now, she believes mask wearing is a really simple step people can take toward helping cut transmission.
“The masks are what work, and they work by blocking what is coming out of an infected person,” Prather said.
“We’ve come to a break in this outbreak where people have a sense of quarantine fatigue, or mask fatigue, and maybe even a sense of complacency where they’re thinking the cases are coming down,” Jade Flinn, a nurse educator for the bio-containment unit at Johns Hopkins Hospital, told HuffPost. (To be clear, they are not.)
“I think many people are thinking the same way,” Flinn added, “and we’re all congregating and going to the same spots.”
But one reason why the outdoors helps limit transmission is simply that there is generally more space: “It’s easier for people to socially distance,” she said.
But air flow may not matter all that much if you’re sitting next to several people for hours. So use the space available to you, Flinn urged, and follow guidelines to keep at least 6 feet between you and others. Think about building layers of safety: Being outdoors is a good start. Being outdoors in a mask is even better. Being outdoors, in a mask, away from others? Better still.
What you’re doing outdoors matters.
Outdoor dining, the Centers for Disease Control and Prevention emphasises, is not risk-free. Sure, you’re outdoors, but you’re sitting stationary with other people. You’re not wearing a mask. You’re coming into close contact with restaurant staff that may be taking precautions, but they’re still people whose exposure levels you don’t know about.
So really think about what you’re doing outdoors, and consider the level of risk. Taking a walk outside with your kids is different than taking your kids to a playground where they might come into close contact with other children. Being outdoors at a relatively empty beach is different than being at a crowded one.
Experts also stress that the length of any given interaction with others influences risk. In theory, you might get the virus from a person running or biking past you outdoors, but experts generally agree the risk there is pretty minimal. If, however, you’re spending hours next to someone — even outdoors — your risk is likely higher.
“It’s all about how much is in the air, and how much you’re near that person,” Prather said. When she takes her daily walk, she acts as though any person she comes close to is smoking a cigarette and she tries to avoid their smoke. (“That’s the path I carve,” Prather said.)
Of course, none of this is to say you shouldn’t do these activities (if current local and national guidelines allow). But do so with the understanding that being outside is not enough on its own to fully prevent Covid-19 from spreading. By adding in physical distance and masks, you’re layering on even more protection.
“Aerosols can go really far. They float. They can live in the air for hours,” Prather said. “They can live in the air for days.”