https://www.nytimes.com/2020/04/17/well/live/coronavirus-contagion-spead-clothes-shoes-hair-newspaper-packages-mail-infectious.html?utm_source=pocket

Your chances of catching the virus when you go outdoors is
extremely low, provided you’re keeping a safe distance from others.

“Outdoors is safe, and there is certainly no cloud of virus-laden droplets
hanging around,” said Lidia Morawska, professor and director of the
International Laboratory for Air Quality and Health at Queensland University of
Technology in Brisbane, Australia.

“Firstly, any infectious droplets exhaled outside would be quickly diluted in
outdoor air, so their concentrations would quickly become insignificant,” Dr.
Morawska said. “In addition, the stability of the virus outside is significantly
shorter than inside. So outside is not really a problem, unless if we are in a
very crowded place — which is not allowed now anyway. It is safe to go for a
walk and jog and not to worry about the virus in the air, and there is no need
for an immediate washing of the clothes.”

Why is it that small droplets and viral particles don’t typically land on our
clothing?

Studies show that some small viral particles could float in the air for about
half an hour, but they don’t swarm like gnats and are unlikely to collide with
your clothes. “A droplet that is small enough to float in air for a while also
is unlikely to deposit on clothing because of aerodynamics,” said Linsey Marr,
an aerosol scientist at Virginia Tech. “The droplets are small enough that
they’ll move in the air around your body and clothing.”

I asked Dr. Marr to explain further, since we’re all getting a mini lesson in
aerodynamics.

“The best way to describe it is that they follow the streamlines, or air flow,
around a person, because we move relatively slowly. It’s kind of like small
insects and dust particles flowing in the streamlines around a car at slow speed
but potentially slamming into the windshield if the car is going fast enough,”
said Dr. Marr.

“Humans don’t usually move fast enough for this to happen,” Dr. Marr continued.
“As we move, we push air out of the way, and most of the droplets and particles
get pushed out of the way, too. Someone would have to spray large droplets
through talking — a spit talker — coughing or sneezing for them to land on our
clothes. The droplets have to be large enough that they don’t follow the
streamlines.”

So, if you’re out shopping and somebody sneezes on you, you probably do want to
go home, change and shower. But the rest of the time, take comfort that your
slow-moving body is pushing air and viral particles away from your clothes, a
result of simple physics.