© 2010 Roy Benaroch, MD
Shannon wrote in, “I just recently read in a magazine that a humid environment as opposed to a dry environment is more hostile to viruses. It sounds a little counter-intuitive to me, however, if it’s true would it be best to run my children’s humidifiers all winter long to stave off the flu and other viruses as this article recommended? I tend to run them more in the winter anyway because my kids tend to have more runny noses or their nasal passages are drier and bloodier. What are your thoughts?”
I’m not sure the viruses, themselves, would even care. Viruses are just little teeny packets of genetic material, with a small handful of protein. They’re not cells, so they won’t “dry out”, and I doubt that their survival would depend much on humidity.
I would guess, though, that a dry environment might make it easier for viruses to invade the nasal lining to make your children sick. Viruses can’t penetrate normal intact skin, and even moist surfaces like the lining of a mouth or nose does a pretty good job repelling these little monsters (the viruses, I mean, not the children.) But once the lining of a nose gets dried out and develops cracks and fissures, the viruses can grab hold and jump right in.
By preventing dry air with a humidifier, you’ll also keep whatever mucus is around nicely wet and runny—that’s good, because thin and runny mucus is less likely to plug up noses and sinuses and get infected with bacteria. Thick and sticky mucus just sits there, an inviting bacterial playground. Thin and runny mucus drains, carrying infection away.
If you do run a humidifier all winter, you’ve got to keep it clean. That warm, moist environment can also become a playground for mold. Once a week, take the humidifier apart, wipe it down with diluted bleach (1 capful per gallon) and let the pieces dry before re-assembling.
What kind of humidifier is best? The ultrasonic ones are easiest to clean, so those get my vote. The kind with the big fabric wicks are just about impossible to clean well, and the ones that use a heating coil could cause burns when Junior pulls it over onto her head.