Sarah Green Carmichael

Keep the Fresh Air Flowing After Covid-19

Humans are essentially an indoor species. A landmark article published 20 years ago found that people spent 87% of their time indoors, and another 6% in the car. There’s little reason to suppose that the rise of flat-screen TVs and smartphones has us spending more time outside.

There are two main problems with this. We’re cut off from nature, which in addition to its beauty, offers all sorts of emotional and cognitive benefits. And indoor air isn’t great. The pursuit of more energy-efficient buildings — a worthy goal — has left our homes and offices rather stuffy.

Here’s where the pandemic has helped: It’s led many of us to get more fresh air than we’ve had in years.

Diners ate al fresco even in the depths of winter. Extended families gathered around the fire pit rather than the dining table. Friends met for long walks instead of drinks. People couldn’t go to the movies, so they went hiking.

Meanwhile, the indoor air has gotten a bit fresher, too. To limit coronavirus spread, workplaces have installed new HVAC filters or added portable air purifiers. People at home have thrown open windows. And all this has very likely helped our brains function a bit better.

In a study led by Joseph Allen at Harvard, researchers tested workers’ cognitive function over the course of six work days, while subtly altering the air quality in the building (though never setting it at a dangerous level). The two days with the cleanest air saw test scores that were 61% and 101% higher than on the days with conventional office air. A follow-up study of airline pilots in a flight simulator showed similar results: Elevated CO2 levels interfered with their ability to avoid collisions or respond to an engine fire.

One reason employees feel drowsy in a packed conference room or students struggle to stay awake in a stuffy classroom is that so many of these spaces are poorly ventilated. As Allen has written, “Casinos figured this out a long time ago,” and began pumping in fresh air to keep customers gambling longer.

Research also shows why daily Covid walks, as inadequate as they may feel, are probably doing a world of good. Time spent in nature has been linked to lower levels of stress, depression, anxiety and ADHD. The benefits are greatest when outdoor time involves greenery, but even a walk down a city street with only a tree or two is better for the brain than staying inside.

As much as it may be nice to get back indoors with other people, and dine without wearing a coat, the past 12 months of cleaner breathing have been a gift, even if it’s come through a mask. It’s a pandemic-induced change that shouldn’t be allowed to disappear into thin air.