Opinion column: It’s the humidity, stupid!

Indoor weather the missing link to fighting coronavirus

The coronavirus has ravaged the world in so many ways like nothing we’ve seen before. But what if the solution was something so simple? In fact, it’s been right under our nose the whole time, and nobody is talking about it.

President Trump and health officials at last week’s news conference suggested that Coronavirus is weakened by sunlight and humidity outdoors. But there’s more to this story. Humidity indoors is the missing link that caused the pandemic in the first place, more specifically dangerously dry indoor air.

Bone dry indoor air was the blasting cap that made Wuhan, New York City and other hot spots explode. Dry indoor air is like an accelerant that turns small viral outbreaks into massive viral bombs. In dangerously dry indoor air, COVID spreads like wildfire. This is so significant because we spend close to 90 percent of our time indoors.

When you look at each hotspot, you’ll notice a number of similarities: high population density indoors, virus and dangerously dry indoor air. This chart, for perspective, demonstrates exactly that in Wuhan.

The key is not relative humidity, but absolute humidity, a metric most of us have never heard of because it’s not part of standard weather reports. But it’s the only metric that counts with COVID because meteorologists can use it to accurately forecast indoor air emergencies.

Safely humidified indoor air protects us in three critical ways:

  1. It’s like Kevlar against COVID for our respiratory tract. By keeping mucous membranes moist, we optimize our natural protective barriers that prevent COVID from penetrating our lungs, nose and mouth. When indoor air is dangerously dry, our body’s natural protections against COVID are impaired.
  2. Humidified indoor air reduces person-to-person spread of COVID by substantially reducing how far the virus travels in the air we breathe indoors. Also, indoor humidity decreases the time that COVID remains infectious.
  3. Virus on surfaces indoors are less likely to dry out, become airborne and get into your lungs when the humidity is 50-60 percent.

The two-part solution

While the government and health organizations are still pushing for social distancing, self-quarantining and increased testing, we must urgently focus on making indoor air safe to breathe.

To win this war we must see the enemy. The critical first step is to make invisible danger visible by adding a new “Vital Sign of Viral Safety” to every weather report, every day, around-the-clock, across the globe. The Viral Safety Index is both a call to action and a plan to keep us safe. On “red” days, we humidify and hydrate. On “Green” days, we can all breathe easier. The Viral Safety Index warns in advance of dangerously dry indoor air in time to make “red” air “green. “Green” indoor air is like social distancing on steroids. COVID does not do well in “green” air.

The second step is to keep indoor air “green” around-the-clock until the crisis has passed. This means increasing the relative humidity indoors to between 50 and 60 percent. In our homes, this can be done inexpensively with a simple home humidifier and a $12 digital hygrometer. This is especially important for the elderly, for people living in densely populated inner cities and for anyone with a pre-existing medical condition.

Just like we did with ventilators and PPE, America must go into overdrive now to make indoor air “green” in nursing homes, hospitals, prisons, meat packing plants, Navy ships and many other vulnerable public spaces. If you own a barbershop, a restaurant, a store or an office, keeping your air “green” will help make customers and employees safer and the economy rebound sooner.

The takeaway

Had we known about the danger of dry indoor air back in February, I believe we could have avoided the shutdown of America.

I believe COVID infections will decline in the coming months because as spring turns to summer, the weather is more “green” than “red.” But we can’t let our guard down because “red” days and even “red” hours can happen in the middle of summer and the middle of the night which can turn a small COVID outbreak into a massive COVID bomb. Rest assured: COVID will be back with a vengeance this fall. By making indoor air “green” across America, we can avoid another pandemic.

COVID isn’t going away anytime soon. Authorities shut down America to prevent catastrophic loss of life and a collapse of the healthcare system. By keeping indoor air “green,” I believe we can keep the curve flat and get America back to work sooner and safer. “Green” indoor air may be our most important public health measure until a vaccine is widely available.

The new battle cry in our war against COVID is: It’s The humidity, stupid! These hopeful words should be on the tip of every American’s tongue.


Indoor weather the missing link to fighting coronavirus

Jeff Gusky M.D. is an emergency physician, National Geographic photographer, and explorer. https://jeffgusky.com/

Jeff Gusky M.D. is an emergency physician, National Geographic photographer, and explorer. https://jeffgusky.com/