If you’ve read my columns for any amount of time, you’re aware of my propensity to urge you to “get outside.”
In my opinion, right now it’s more important than ever. This may make some of you feel uncomfortable, but I believe we are safer outside and in nature than we are in other places that we are frequenting these days. Stores, shopping centers, gas stations...all of these spots may get us sick. It’s very unlikely that “the woods” will. And there is some pretty solid research to back this up, which I will share in a moment.
There is a plethora of scientific literature and anecdotal experiences that show that outside air is immensely safer than indoor air within constrained spaces. Recent studies have found that the vast majority of transmission in areas like New York City are due to public transportation (subways, busses, etc). Dense and heavily populated areas (perhaps like the stores that are currently deemed “essential”) may put you at more risk than the Kettle Moraine State Forest.
n One study from last month in China examined 1,245 confirmed cases and found that exactly two of the cases could be attributed to transmission in an outdoor environment from one person to another.
n Nishiura et al., 2020: Transmission of COVID-19 in a closed environment was 18.7 times greater compared to an open-air environment (95 percent confidence interval).
n Lidia Morawska, professor and director of the International Laboratory for Air Quality and Health at Queensland University of Technology in Brisbane, Australia, stated the following: Being outdoors is safe, and there is certainly no cloud of virus-laden droplets hanging around.... Firstly, any infectious droplets exhaled outside would be quickly diluted in outdoor air, so their concentrations would quickly become insignificant. In addition, the stability of the virus outside is significantly shorter than inside. So outside is not really a problem.... It is safe to go for a walk and jog and not to worry about the virus in the air.”
n There is deep experience during other pandemics that placing patients outdoors greatly enhanced their recoveries and lessened spread to others. In fact, during some pandemics (like 1918-1919) open-air hospitals were built and patients were moved outside into the sun, with very positive impacts. In fact, “more might be gained by introducing high levels of natural ventilation or, indeed, by encouraging the public to spend as much time outdoors as possible,” as one study stated.
n There is extensive literature that says ultraviolet radiation from the sun can quickly degrade the viability of viruses in the air (e.g., Schuit et al. 2020: The Influence of Simulated Sunlight on the Inactivation of Influenza Virus in Aerosols). As noted by Lytle et al., 2005: “Sunlight or, more specifically, solar UV radiation (UV) acts as the principal natural virucide in the environment.” Duan et. al. 2003 found that “UV irradiation can efficiently eliminate the viral infectivity”
n A fascinating study of virus transmission in dorms at the University of Maryland compared students in rooms with poor ventilation, with those who kept their windows open all the time (Zhu et al., 2020). Those with open windows had one-fourth the rate of respiratory infections. Some did complain of being cold, though.
n Virus particles rapidly disperse in the open air as noted by Case Western Reserve University Hospitals infectious disease specialist Dr. Amy Edwards: “When someone coughs or sneezes, most of the virus drops to the ground within six feet pretty quickly. That’s why doctors recommend social distancing. If a few particles remained in the air, they would be killed off by UV light in the sun, or blown away by the wind.”
Personally, I still highly recommend excellent hand washing, disinfecting surfaces (like your smart phone screen!), and social distancing. As stated above, the droplets from a cough, sneeze, or breath don’t travel more than six feet. So, maintain social distancing...but do it outside! Use an entire parking lot, and then go get some fresh air. Sometimes something as simple as sunshine and fresh air can make all the difference.
(The contents of this column are provided for general informational purposes only and are not intended as a substitute for professional health care advice. Do not use the information in this column for diagnosing or treating any medical or health condition.)