WUWT by Leo Goldstein March 28, 2020
Bullet points:• COVID-19 spreads mostly indoors by person to person and person to surface to person transmission
• Increasing humidity indoors to 50%-60% is a safe and promising method to fight COVID-19 spread
Increasing Indoor Humidity to Constrain COVID-19Indoor temperature, humidity, and ventilation must be increased in public and private buildings in all COVID-19 affected areas. Here, indoor temperature of at least 75°F (24°C) and relative humidity levels of 50%-60% are recommended.
SummaryIt is a common knowledge, confirmed by the rigorous body of research, that low temperatures and low humidity contribute to flu-like virus epidemics, while high temperatures and high humidity reduce or even prevent flu-like epidemics. Good ventilation (rapid exchange of indoor air, which potentially contains viruses, with clean outside air) is another important factor that decreases the virus spread. COVID-19 is caused by a coronavirus SARS-CoV-2. Coronaviruses and Influenza viruses are enveloped RNA viruses from the respiratory virus group. Therefore, the knowledge gained by the vast amount of prior studies of such viruses is fully applicable to the current epidemic.
People in the US and other developed countries spend most of their time indoors. The typical indoor conditions are characterized by very low relative humidity, lower than optimal temperature, and bad ventilation. Today, the seasonality of flu-like illnesses is better explained as an indirect impact of cold weather. Heating without humidification dries indoor air, and the low humidity contributes to virus survival, infectivity preservation, and transmission. There is evidence that these indoor environment conditions have been worsening over the last 10-15 years.
The suggested temperature and humidity for decreasing the spread of viruses is within most existing regulations. However, the humidity of many indoor environments typically goes unchecked and frequently falls below 30%, per Quinn and Shaman (1). Reisman and Das (2) shows that an increase of humidity in schools, from ordinary ~28% to ~45%, decreases influenza-like illnesses among children by 2.3 times in wintertime. Thus, increasing indoor humidity levels and temperatures, as stated above, would yield immediate benefits beyond just slowing the spread of COVID-19. These measures also seem to have no downsides, at least over a few weeks’ period.
More:
https://wattsupwiththat.com/2020/03/28/increased-indoor-humidity-may-decrease-coronavirus-covid-19-transmission/
