During the past month, the fear of coronavirus had spurred political leaders to close parks and nature areas throughout the country.
In Washington State, all state parks and state lands managed by the Department of Natural Resources are closed through at least May 4. Here in Seattle, all major city parks were closed last weekend and parking lots for city parks are still shuttered. Picnicking, barbecuing, and any sports are illegal in Seattle parks. In California, hundreds of state parks, including many major beach areas, have been closed, and parking has been blocked off for all state recreation facilities.
All of these closures are predicated upon the assumption that coronavirus infection is a serious threat in outside air and that virus spread is significant outdoors. As documented in this blog, such an assumption is not consistent with the best science. Furthermore, there is strong evidence that restriction of public access to parks and natural areas threatens both the physical and mental well being of the population and thus is counterproductive. Many politicians claim that parks must be closed to prevent large groups from gathering and spreading the virus. As we will see, such worries appear to have little basis in fact.
Is Outside Air Safe?
After searching through the literature and talking to a number of doctors and researchers, I could not find a single paper suggesting significant outdoor transmission of COVID-19 or any coronavirus. But there is a huge literature and long historical experience suggesting that outside air is immensely safer than indoor air within constrained spaces.
Here are a few examples and some quotes from medical experts on this point:
- Nishiura et al., 2020: Transmission of COVID-19 in a closed environment was 18.7 times greater compared to an open-air environment (95% confidence interval).
- Lidia Morawska, professor and director of the International Laboratory for Air Quality and Health at Queensland University of Technology in Brisbane, Australia.”: 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”
- 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. To quote one paper on the subject (“The Open Air Treatment of Pandemic Influenza”, which documented the reduction of mortality and morbidity in the open air: “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.”
- There is an extensive literature that ultraviolet radiation from the sun can quickly degrade the viability of viruses in [ … ]