Are antibacterial building materials making you unhealthy?

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Architects and chemists of building materials need to embrace bacteria — and need to stop promoting practices that spur antibiotic resistance.

As green design turns its eye to health, architects are looking not only at chemical properties in materials but also at the microbes around us to promote environmental health and sustainability and human health.

Rare and minor metals, or chemicals made from metals such as cadmium, titanium and molybdenum, are in everything in our buildings from sheeting, to LEDs, to solar panels, to appliances, equipment and paints. We use them, for example, to enhance steel and prevent corrosion.

Tracing the environmental and health consequences of acquiring and using and recycling these metals is unwieldy, from destructive open pit mining in Mongolia to unregulated waste disposal of materials in China to the unstudied health effects of these metals, Ken Geiser of the Lowell Center for Sustainable Products at University of Massachusetts told an audience at the BuildWell symposium in San Francisco.

With an increasing emphasis on health and wellness in green design, how are building professional addressing this heretofore somewhat unexamined aspect of their supply chain? Labeling and transparency of materials is a start. Geiser's recommendations to design teams: Check all the components of a product, know your sources and, until we can clean up our supply chains, put a gap in between construction and move-in dates.

The microbial cloud

Erica Hartmann, a Fulbright scholar at the Biology and the Built Environment Center at the University of Oregon, is the first person to look at how chemicals in building materials affect microbes.

A healthy "microbial cloud" is not necessarily intuitive. You may be surprised that scientists claim more microbes are healthier than fewer microbes in a space. That’s because it’s better if pathogens face more competition. Outdoor air contains more microbes and is healthier as a result. Scientists are finding hospitals with operable windows have fewer pathogens, for example.

Manufacturers, however, operate on the opposite assumption — that more microbes are bad, and they have set about diligently eliminating them. Hartmann disclosed an alarming fact: Manufacturers of all kinds of building materials and products place an anti-microbial called triclosan in practically everything from paint, tiles and carpets to keyboards.

But antimicrobials don’t stay there. They end up in dust. "Almost all dust from indoor environments contain triclosan," she explained to the BuildWell audience. Contrary to their intention to kill bacteria, antibacterial products seem to make bacteria stronger.

"There is a corollation between tricloasan and antibiotic resistance. So, merely by being inside, you increase your chance of an antibiotic resistant infection," according to Hartmann. (This is why Kaiser Permanente has banned the use of antimicrobials in interior building products in its hospitals and facilities. It also bans anti-bacterial soaps for the same reason.)

Hartmann already knows outdoor air improves the health of an indoor microbiome, so what about sunlight? In fact, she is currently studying glazing on windows to see how blocking UV light affects the microbiome in a room.

Green chemistry

By studying what’s different about how nature handles molecules and how it manufactures and recycles products, innovative manufacturers are learning about what’s wrong with industrial processing of materials.  

John Warner of the Warner Babcock Institute used to work at Polaroid. Then he went to work on environmental toxicity for the EPA, and now has his own company doing things such as developing an asphalt product that contains a molecule that allows it to rejuvenate itself rather than be ripped out and repaired as it ages.

This may sound like magic but "bio" products that mimic nature in their manufacturing process hold huge potential, both for reducing environmental impacts and for increasing profits. Pike Research stated "green chemistry" will be a $98.5 billion global industry by 2020 as many safer and greener alternatives make their way out of the laboratory and into the market.

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