Why Some Experts Say Humidifiers Could Help Against Covid-19
Your warm, dry home can be a hotbed for Covid-19 infections, but is a humidifier helpful and safe?
When a coronavirus particle takes flight from an infected person’s mouth or nose, encased in a tiny airship of spit or snot, it must quickly invade another human host and unlock a respiratory-tract cell before all its spiky “keys” melt away like a Wicked Witch splashed by water.
How long the virus remains viable and infectious — stable, as scientists say — depends on the environment. “The virus is more stable as the temperature and the humidity decrease, and it is less stable as the temperature and humidity increase,” says Lloyd Hough, PhD, head of the Hazard Awareness and Characterization Technology Center at the Department of Homeland Security.
Humidity not only affects the virus itself, but also the front lines of our immune system. From the nose on down, the human respiratory tract filters out particles that would do us harm. That filtering system and other aspects of our immune system don’t work as well in dry air, somewhat like how a dry sponge doesn’t clean as well as a wet one.
The specifics are below. But here’s the upshot, from Akiko Iwasaki, PhD, a professor of immunobiology at Yale University: “When cold outdoor air with little moisture is heated indoors, the air’s relative humidity drops to about 20%,” Iwasaki says. “This dry air provides a clear pathway for airborne viruses, such as [the virus that causes] Covid-19. In addition to this, our immune system’s ability to respond to pathogens is suppressed by dry air.”
“The virus is more stable as the temperature and the humidity decrease, and it is less stable as the temperature and humidity increase.”
Iwasaki is one of several scientists calling on the World Health Organization to offer guidelines for minimum humidity levels in public buildings. Further, she tweeted recently, “Let’s humidify our homes.”
However, given the evolving science on a virus still only months old, Hough and other scientists are not convinced a humidifier in the home will offer…