But the precautions we take are not necessary or realistic for the general public. Even if there were no shortages of PPE (personal protective equipment), people can’t be expected to wear a gown, N95 mask, face shield, head covering, boots, and gloves to go to the grocery store. So what’s the real risk in the community for contracting the coronavirus? And how best to mitigate that risk? The answers to these questions involve a number of factors. Your specific geographic location (population density, viral presence), underlying health (including genetics), and adherence to physical distancing and realistic personal protection measures (such as wearing facial coverings) ultimately determine your overall exposure and infection risk. What we do know is this: The virus is highly transmissible, especially in crowded settings with high traffic, no physical distancing, and poor hand hygiene.
Looking at How the Virus Spreads
To fully evaluate risk, we have to take into account how the virus spreads. Based on recent studies, the primary and most efficient modes of transmission are coughs and sneezes, which expel respiratory droplets as far as six feet. You are at highest risk of becoming infected if you inhale droplets containing viral particles without any protection from a mask or other facial covering. That said, a recent study found that speech-generated droplets could linger in stagnant air for eight to 14 minutes in a laboratory setting. (Of note, the researchers did not study this phenomenon using the coronavirus.) There is also debate as to the importance of transmission in aerosolized droplets, based on another lab study demonstrating that these may linger in the air for up to three hours. These studies reinforce the importance of wearing a mask in public. You can also become infected by touching contaminated surfaces and then touching your face, but it’s important to think about relative risk. While the virus can survive on surfaces from several hours to several days, transmission would require direct contact with hundreds or even thousands of viral particles. Ultimately the infection risk from contaminated surfaces — a metal rail, a cardboard shipping box, a plastic takeout food container — appears to be relatively small. RELATED: 10 Misconceptions About the Coronavirus
Determining Higher-Risk and Lower-Risk Situations
So how do we use this information to make important decisions in daily life? Is it safe to sit in your front yard? Walk down the street or in a park? Drive your car? Go to a grocery store or the post office? Open a package? Order food delivery? All of these actions are associated with some degree of risk, but there is certainly higher risk with some than with others. This was detailed in a recent blog post by Peter Tippet, MD, PhD, in which he offers a more concrete and realistic explanation of risk than can be gleaned from simply reading the guidelines by the Centers for Disease Control and Prevention (CDC). As Dr. Tippet notes, your house, yard, and the interior of your car are generally considered safe (assuming you don’t invite outsiders in). For the general population, a trip to the grocery store or post office requires basic caution but not overwhelming fear. If you wear a mask, stay six feet apart from others, and don’t touch your face before thoroughly washing your hands, the chance of acquiring the virus is quite low. Wiping down cartons with cleaning wipes and letting groceries, other than perishables, sit for a few hours will further lower risk. RELATED: Food Safety and COVID-19: A Guide for Handling Groceries and Takeout Because the risk of exposure also depends on how often you visit high traffic areas and how much time you spend there, it is best to make your post office trips as quick and infrequent as possible. And be aware of situations that place you at even higher risk for exposure and try to avoid them — for instance, by not going to the grocery store at times when it’s likely to be crowded. Note: You’ll need to be even more careful if you are medically compromised — for instance, if you’re older, obese, or have heart disease, high blood pressure, or chronic lung disease. If at all possible, have someone shop for you and leave your groceries at your front door rather than venturing out to highly populated places like the grocery store. RELATED: Coronavirus Shopping List: What to Buy and Skip
Taking a Balanced View
This has been a very scary and confusing time and it doesn’t help that there are still a lot of unknowns about COVID-19. News stories have highlighted the extremes, with videos of people at beaches en masse taking no precautions, followed by interviews with others who are terrified to sit on their front porch. My best advice is to take what we do know about the virus and use that knowledge to mitigate risk with equal amounts of practicality, caution, and calm. Robert Glatter, MD is an attending physician in the department of emergency medicine at Lenox Hill Hospital in New York City and an assistant professor of emergency medicine at Zucker School of Medicine at Hofstra–Northwell in Hempstead, New York.
