Staying home and social distancing remain the best way to control the spread of the COVID-19 virus, but if you must come into contact with other people, you’re safer outdoors than indoors. We all occupy an area in three dimensional space, and as we move away from one another, the volume of air space on which we have an impact expands enormously. “If you go from a 10-ft. sphere to a 20-ft. sphere you dilute the concentration [of contaminated air] eight-fold,” says Dr. Christopher Gill, associate professor of global health at Boston University School of Public Health. That’s important because a single sneeze can project particles a distance of 9 meters, or about 27 feet. The less concentrated those particles are in the air, the less danger they present. “Within seconds [a virus] can be blown away,” Gill says.
Sunlight may also act as a sterilizer, Gill says. Ultraviolet wavelengths can be murder—literally—on bacteria and viruses, though there hasn’t yet been enough research to establish what exactly the impact of sun exposure is on SARS-CoV-2, the virus responsible for COVID-19.