Covid and Low Humidity

Covid-19 has killed almost 250,000 Americans and infected 11,000,0000 or more.  On Friday November 13th, Johns Hopkins reported 184,000 new cases of covid-19.  Deaths are on the increase as well, going from 700 deaths/day in September to over 1100/day now.  According to the Covid Tracking Project, almost half the states are reporting record covid-19 hospitalizations.  This disease is  surging  in the US., Washington, and Clark County.  The  Covid Tracking Project was created for The Atlantic by Alexis  Madrigal whose mother, Elizabeth, lives in Ridgefield.

Moderna and Pfizer are in trials of two very promising vaccines with over 90% success in preventing disease.  However, it will likely be a few months before these vaccines are readily available.  In the meantime, we need to follow the guidance the state and county have required.   You can’t get the disease if you are not exposed to it, nor can you pass it on if you don’t have it.  We are asked to practice social distancing, wear masks,  and practice good sanitation.

The increase in cases now is alarming and people can  get sick even if they take precautions.  The surge in the autumn was predicted.  Much of the prediction was based on the knowledge that other viral diseases increase in the autumn and winter.  Earlier this year, epidemiologists stated that with colder and drier air the virus can survive longer.  Now that is not mentioned as much.  With it being colder and darker, the emphasis is more on people being indoors and thus closer together.  In our area, rainy days are  also a reason to be indoors.

There may be another consideration and that is of a drier environment, especially indoors.  There is a bacterial disease called meningitis can be spread as an airborne.  Many years ago, I read an article that suggested that if it was too dry, then this bacterium could infect through the sinus membrane.  In Africa and Asia there are occasional epidemics of meningitis.  There was a large study done that noted that in times of extreme dryness there was an increased incidence of meningococcal disease.  The study’s authors suggested other airborne diseases could gain access  as well if it is too dry.

There was a study done by researchers at Oregon State University that researched  low humidity and influenza.  They looked at death records of people in the US noting date and location.  Then,  they looked at weather for that area at the time of the deaths.  They found a correlation between times of low humidity and death from the flu.    Another study focused on infecting susceptible rats with an influenza virus.   Some were kept in a low humidity environment and some were kept at a higher humidity.   Again, rats did better in an environment that was not too dry.  Another article about the common cold suggested colds could be more easily transmitted if the humidity is low.  Nosebleeds are more common if the humidity is low.  Dryness damages the sinuses and suppresses the immune system in both the sinuses and lungs.

Covid-19 is not meningitis, a cold, or the flu, but it is spread the same way.  It seems reasonable that the virus that causes covid-19 may be more transmissible if the air is too dry.  The study done by OSU suggested that it may be of benefit to increase the humidity indoors.  The recommendation for the most comfortable indoor humidity is 40-60%.    East of the cascades it can be very cold and dry in the winter.  Here on the west side, it is wetter.  Still, with homes being heated, the air becomes much drier.  A few weeks ago, inside my home, the humidity was only 37% when we had our first frost.  So, I’m thinking of ways to keep the humidity around 50-60%.  If we do have some very cold weather, as we sometimes do here, the inside humidity  may be very low.  It may only  help  a little with covid-19 or even with colds and flu but certainly would be more comfortable to  increase the humidity at times.

By Paul Snoey

About Paul Snoey

I have a degree in Biology and Environmental Science from WSU Vancouver
I am very fond of Gee Creek and Allen Canyon Creek and do a lot of volunteer work to restore these creeks.

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