Engineering Buildings To Promote Good Bacteria

Microbes are everywhere, and most are harmless. But tightly sealed buildings–like hospitals or offices–create places where only dangerous bugs survive. Time to rethink our ventilation.


Jessica Green, an ecologist and engineer at the University of Oregon, studies microbes that are everywhere in our environment. She realized that–despite our great fears of them–they may also be the key to keeping us healthy. As director of the Biology and the Built Environment (BioBE) Center, which is “training a new generation of innovators and practitioners at the architecture-biology interface,” Green has found that by trying to keep our buildings clean and sealed, we may just have been making them worse for our health.

Green is advocating that architects design structures with not only
people in mind, but also microbes. She sees a unique opportunity to
promote the diverse microbe communities we want in our buildings (the kind that keep us healthy), while
monitoring species dangerous to human health, similar to the how the U.S.
National Park System manages and monitors wildlife in proximity to
human settlements.

Doctors once prescribed fresh air as a cure, but today’s nearly hermetic hospitals and office buildings deliver exactly the opposite, by relying on extensive mechanical ventilation. The consequence is that the microflora in many buildings–those invisible bacteria, viruses, and other microbes around us–is dominated by human-linked bacteria and pathogens, compared to the relatively harmless microbe communities in well-aired buildings or the outdoors, made up mostly of benign bacteria from plants and dirt. At least, this was the finding from Green’s study comparing the microflora of mechanically ventilated hospital rooms to those in rooms with open windows, and the microbes outside. Without the benefit of direct outside ventilation, people were more likely to encounter human pathogens.

“Humans in the developed world spend more than 90% of their lives
indoors, where they breath in and come into contact with trillions of
lifeforms invisible to the naked eye,” says Green in a 2011 TEDtalk.
“Buildings are complex ecosystems that are an important source of
microbes that are good for us, and some that are bad for us.”

In the future, the BioBE’s “hypothesis-driven, evidence-based approach to understand the built environment” could lead to new kinds of buildings–ones that give us friendlier microscopic neighbors.

[Image: Flickr user LaMenta3]


Reach Michael J. Coren via Twitter or email.


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