Risk ranking of everyday activities for COVID-19, according to an infectious-disease expert

• The risk of becoming exposed to the COVID-19 coronavirus increases in some cases and decreases in others
• Dr. Susan Hassig, an epidemiologist at Tulane University, shares how to think about managing the risk of everyday activities
• Analyze situations by looking at the distance you will be able to maintain with others, the diversity of households in the area, and the duration of your activity and interactions.

Following is a transcript of the video.

Susan Hassig: I basically try to remind people that this virus isn't just out in the environment waiting to jump down your respiratory tract. It's captured, it's acquired from interacting with people.

Narrator: This is Dr. Susan Hassig. Hassig: I'm an associate professor of epidemiology. I was not one of those that rushed to a restaurant the first weekend they opened up. Given the opportunity, it will spread.

Narrator: Staying safe from COVID-19 doesn't require isolating in a bunker, but it does mean weighing different risks based on the situation. You can think about everyday activities in terms of the three D's: diversity, distance, and duration. Diversity is the number of households mixing. So risk is higher if you're meeting with people you don't live with, particularly if you don't know everywhere they've been in the past two weeks. It's also higher if your area has had lots of recent cases or if testing is too limited to know how many active carriers are around. Distance is an issue whenever you're less than six feet from other people, especially if you're indoors or people aren't wearing masks. Lastly, it comes down to duration. Are you running past people in the park, or are you having an extended conversation or encounter?

Hassig: So, the challenge that you have is kind of translating that into normal day-to-day behaviors. Pool-party kinds of situations. There's food involved, and there's more than likely, at an adult gathering, alcohol involved. I would be concerned about mask wearing in that context, which actually should be part of the mix. When you're thinking about distance and density, those are two things that can be really problematic to maintain in that kind of an environment, and there may be social pressure not to maintain the distance.

Bars are really designed to attract people in in large numbers and to get up close and personal, so that's one of the venues that I am most concerned about when they eventually are allowed to reopen.

Houses of worship, very frequently the population present there is generally older, potentially more vulnerable to consequences of coronavirus infection, but there are also lots of activities that can be potentially really problematic. We know singing results in tremendous projection of air and virus, potentially.

Group sports, when you're physically working out, you're gonna be breathing a lot harder. And forced exhalation, if you happen to be infected, is a great way to expel a lot of virus. In the gym context, what I've seen, they have broken up those banks of treadmills. They've removed some of the machines or spaced them out to provide distance between individuals on them. I think the real challenge is, I think, in some respect, is for the trainers. The indoor dinner party is also fairly high. You may have some reasonable distancing, but probably not enough. And then when you're eating you're obviously not wearing a mask. If it's households comingling, that's where, you know, the real issue does come in.

Mass-transit options, basically they're relatively small, enclosed spaces with potentially lots of people in them for an extended period of time. Whether it's a surface bus or a subway or an airplane, you've got lots of possibilities going on there. A date, one on one, making sure you know who it is that you're having a date with before you actually get into a physical proximity with them is probably a really good idea. Troll their social media to see what they're posting, and if they've been to a couple of bars or parties, I wouldn't go on a physical date with them. I'd keep it virtual.

Dental visits are close proximity, certainly with a dental hygienist for an extended period of time, and as a patient your mouth is wide open, ready to accept virus. I'm assuming they would screen, physiologically, any of their patients. I think the other kinds of personal care and close-interaction services, I mean, we've seen the example of what happens when a hairstylist goes into work sick, and that's really problematic.

Airbnbs, I think it really depends on the proprietor and what kind of interval they have between their guests. Because, I mean, we know the virus will not survive more than two or three days on any kind of surface without renewed contamination. And so I would be very concerned about an Airbnb that was flipping it the same day from one client to the next. In a hotel I have a little bit less concern, although I would like to think that they are leaving at least one day in between guests in individual rooms, preferably two days.

Shopping in general is relatively low, but in a mall, where there may be opportunities for people to gather, is what I would be concerned about. Public pools, the water itself is not a risk. But if that water is full of people, you know, shoulder to shoulder or whatever, it's a risk. It's a risk environment.

I think campsites are relatively safe, as long as you're not, again, gathering around the campfire in close proximity with five other households. Walking in the park or whatever, where you're not stopping and chatting for 10 minutes with an old friend, you know, I'm not sure that you really even need to wear a mask in that context, because you're not spending any length of time in proximity to anyone, unless, of course, it's the crowded boardwalk in New Jersey or North Carolina or wherever else.

Narrator: All of this varies from situation to situation and person to person. The three D's may not be enough if you're high risk or interact with people who are, as even moderate risk can lead to major consequences. Hassig: There are some people ready and willing to accept the consequences of engaging in certain kinds of activities. But here it's more than just about an individual. It's really about your collective sphere of friends, family, and those that you interact with.