The rankings, based on interviews with four Michigan public health experts by local news source Michigan Live, assess the risks various activities pose for the spread of coronavirus. All four doctors and infectious disease specialists based their assessments on the same framework used by most public health experts, considering "whether it's inside or outside; proximity to others; exposure time; likelihood of compliance; and personal risk level," or put another way, time, space, people, place.
The ideal combination, health experts agree, is a short amount of time spent in a large (preferably outdoor) space, with few people, in a place where virus transmission levels are already trending low and social distancing guidelines are likely to be enforced.
For the chart that's going viral, 36 different activities are rated on a scale of 1 to 10 in terms of the likelihood of spreading the coronavirus. Getting takeout from a restaurant—which happens quickly outside at the curb and with plenty of risk-reducing practices in place including masks and contactless pickup—is ranked a 1.
Amusement parks, by contrast, where lots of people are gathered together all day, talking (and sometimes screaming) and touching a lot of the same surfaces, are ranked an 8.
Playgrounds are considered a 6. "Kids tend to touch their mouth or cough or sneeze on surfaces. You can't make little kids separate by 6 feet—it's just not the way they work," Dr. Dennis Cunningham, McLaren Health Care medical director for infection prevention, told Michigan Live. "I'm not a big fan of playgrounds right now."
Here's how various activities were ranked in terms of virus transmission risk:
It's worth noting that the experts who created these risk assessments were being interviewed by a local news organization and probably had virus transmission levels in Michigan in mind as they made their suggestions. (Speaking as a native Midwesterner, seeing "pontoon boat rides" on the list was a big clue as to its origins.) But they are based on a widely-supported understanding of coronavirus transmission: Most cases come through person-to-person contact, and mostly indoors.
Other experts have reinforced the importance of local virus transmission levels—the number of cases, the amount of testing, and the number of positive test results in your area—when considering how risky an activity might be this summer. A recently-published guide to living in a pandemic by the New York Times suggests that the number one risk factor to keep in mind is how active the virus is in your area.
And of course, another important consideration is your family's particular tolerance for risk. If you have older or immunocompromised people in your household, if you are pregnant or if you have a newborn, your tolerance for risk is likely to be very low—and you may view these risk assessment rankings differently. You know your family's situation best.