Bacteria are a familiar part of indoor environments – always present, difficult to remove – and a lot of those microbes aren’t friendly (remember Legionnaire’s Disease?). While cleaning is often ineffective – and can even be counterproductive – there are solutions to keeping buildings healthy. New research is looking into design methods that cooperate with biology, rather than fighting it. In the process, this work could bring microbe management into mainstream architectural design.
The Ecology of us
Building health starts with us or, rather, our microbiome. This is the community of lifeforms that each of us carries around. There are, in fact, ten times more microbial cells than human cells in our bodies. Medical science is still exploring the relationships between the types and numbers of these microbes to our health, but there’s no debate that their well-being determines our overall well-being.
Buildings have microbiomes, too, and we contribute a lot to their makeup. We share our microbes with indoor spaces by living in them, and buildings share their microbes with us. It’s the mixing of these populations that affects our health in processes that we don’t yet fully understand. Designing for healthy living requires better information about how indoor microbe populations emerge, grow, and change in response to human use.
Several research teams are now working to build that knowledge base.
What’s on the walls?
Bacteria types can be distinguished by their DNA. Fortunately, the expense, complexity, and time requirements of DNA sequencing have all dropped dramatically in recent years, resulting in a proliferation of studies to survey and classify microbe populations in places like hospitals and public transportation systems.
Other work measures the growth and spread of bacteria on different kinds of interior surfaces, under different environmental conditions such as temperature and humidity.
Figuring out which microbes are where, and how they live, will inform architectural designers about what concerns they must address for building health and safety. How they address these concerns is limited only by their imagination.
One design approach involves permeable surfaces, impregnated with “good” bacteria and layered onto carpeting, furniture, and walls. These bio-active surfaces could continuously distribute useful microbes into the environment to counter harmful pollutants or pathogens. An alternate approach employs air conditioning systems to distribute beneficial microbes.
Active systems like these are likely to stay in the “proposed” category, however, until the risks of releasing bacteria into complex environments are more clearly documented.
A more modest, but more practical approach to fostering a healthy population of indoor microbes is being carried out by the architecture firm of Skidmore, Owings, and Merrill (SOM). The firm is responsible for building a new Public Safety Answering Center (PSAC II) in New York. Air quality is a big design factor here, as some emergency operations (such as a HAZMAT spill) may require sealing off the building air supply from the outside.
SOM designers and the Center for Architecture, Science and Ecology (CASE) have included an Active Modular Phytoremediation System (AMPS), otherwise known as a “bio-wall,” in the center design. AMPS is tied directly to the air conditioning system, which draws air through a network of plant roots. Microbes in the roots filter out organic compounds and other toxins, and generate fresh oxygen. It’s a simple concept but, once the center is operation, should go a long way toward controlling the indoor microbe environment.
More tech or more trees?
It will likely be some time before we see aggressive attempts to alter the building microbiome, as there’s still a lot we don’t know about microbe populations of indoor environments. For now, simply installing more green plants may be the most direct way to improve indoor health.
Investigations like these, however, will almost certainly yield new architectural design tools and encourage a new vision of buildings as living ecosystems, capable of enhancing human health through microbe management. At the very least, such work promotes the idea of the built environment as a biological – as well as structural – extension of who we are.