The Next Big Thing in Healthy Building is Microscopic
Healthy building is an increasingly important topic
in the broader sustainable built environment arena, but much of the
focus is on active design, healthier materials, and designing systems for
air quality and comfort. These are important common sense features,
but one of the more interesting areas of research in healthy
building is something much smaller (microscopic, in fact!) and
naturally occurring: microbes.
Many of us have some degree of germphobia and have
been conditioned to fear the things we cannot see, and for good
reason-touching a doorknob or shaking a hand and than
absentmindedly scratching your nose can land you in bed with a
miserable cold, flu or worse. To minimize the threat, we wash with
anti-bacterial soaps and use harsh cleaning products to
hyper-sanitize the surfaces around us.
But what if this shotgun approach to killing bad bugs
was actually setting us up for worse infections? We know that
bioclimatic design with passive, climate-responsive approaches to
maintaining indoor comfort can offer a more efficient and effective
alternative to using brute force energy in mechanical systems.
Similarly, embracing the naturally occurring microbiome could offer
a better solution to maintaining healthy indoor environments,
compared to hyper-sanitization.
Microbes are everywhere. The human microbiome
includes a microbial cloud, a unique personal cloud of
invisible organisms (bacteria, fungi, etc.) that hovers around us.
The total number of cells in the microbiome that is in and around
you outnumbers your own cells 10 to 1. According to research by the
Oregon's Biology for the Built Environment Center (BioBE), your
body hosts a whole ecosystem of millions of living things. While
some of these are potential pathogens to be avoided, scientists are
just beginning to understand the array of other beneficial bacteria
and fungi, which can have significant health benefits.
You may have heard of the hygiene hypothesis that
suggests exposure to dirt at a young age may strengthen our immune
systems and reduce our susceptibility to allergies. A recent study by the University of Chicago supports
this hypothesis in its findings that exposure to microbial life on
farms (a dirty environment) gave kids a natural resistance to
asthma, allergies and other diseases. This suggests our increasing
rates of asthma and allergies may be related in part to our
lifestyles being too clean.
Another growing area of health concern is super bugs,
the emergence of antibiotic resistant bacteria due to overuse of
antibiotics in humans and in livestock, as well as the
proliferation of antibacterial soaps and sanitizers. One of the
most notorious is Methicillin-resistant Staphylococcus aureus
(MRSA) infections caused by a type of staph bacteria that has
become resistant to commonly used antibiotics. This is an area of
particular concern in health care and nursing home facilities.
How can we apply this evolving science to building
design and operation? We can start with a basic understanding of
biodiversity. Without the regular application of chemical
herbicides, the monoculture of a lawn can be quickly overrun with
dandelions. By contrast, in a healthy forest we rarely see any one
species of plant dominating the landscape because the diversity of
species and their interdependence keeps the whole system in
balance. The microbiome is no different. In a typical sealed
building, air is recirculated and janitorial practices often focus
on hyper-sanitization, so that when pathogens are introduced
(through coughs, sneezes, etc.), there is little to resist their
spread. Like the forest, a diversity of micro flora and fauna may
prevent any one organism, especially harmful bacteria, from
proliferating and increasing the risk of infection.
A recent study by the BioBE inventoried the
biogeopraphy in dust within a LEED-certified building on the
University of Oregon campus in Eugene, Ore., with some spaces
having only mechanical ventilation and others with mixed-mode,
natural and mechanical ventilation. The mechanical-only spaces were
found to contain higher concentrations of potential pathogens and
lower diversities of organisms, while spaces with operable windows
experienced the opposite. Not surprisingly, microbes common to
outdoor environments were present in greater numbers in spaces with
operable windows, apparently helping to keep other microbe
populations in check.
Another experiment looked at the impact of daylight
on bacterial diversity in dust. It found that dark spaces had
greater concentrations of bacteria, while light exposure led to
lower concentrations, but greater diversity of organisms. More
research is needed to draw firm conclusions to guide design
recommendations, but these results reinforce what we already know
intuitively: that is, buildings with plentiful daylight and
operable windows tend to be better for our health. In addition to
designing for healthy microbiomes, now we can also introduce a
blend of helpful microbes into our buildings as a form of probiotic cleaning to reduce and control
pathogen bacteria better than chemical cleaning regimens. Companies
like BetterAir, Hollywood, Fla., are working with
researchers to pioneer this approach.
While regular hand washing and building cleanliness
upkeep are still recommended, we should nevertheless rethink our
approach to creating and maintaining a healthy built environment
based on recent discoveries about the rich and diverse microscopic
world around us. Some examples of steps in the right direction
include designing our cites with natural areas and gardens so that
kids can get outside and get dirty, letting the outside into our
buildings (including micro organisms), and dialing back the use of
anti-bacterial products. To do this effectively, we need research
to better understand how to design and operate buildings in a way
that supports a beneficial microbiome while limiting the potential
for harmful microbes. Perhaps your next project team might include
a microbiologist along with the typical crew of engineers.
Alan Scott, FAIA, LEED Fellow, LEED
AP BD+C, O+M, WELL AP, CEM, is an architect with nearly 30 years of
experience in sustainable building design. He is a director with
YR&G Sustainability in Portland, Ore. To learn more, visit www.yrgxyz.com and
follow Scott on Twitter @alanscott_faia.