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TEDGlobal 2011

Jessica Green: Are we filtering the wrong microbes?

July 14, 2011

Should we keep the outdoors out of hospitals? Ecologist and TED Fellow Jessica Green has found that mechanical ventilation does get rid of many types of microbes, but the wrong kinds: the ones left in the hospital are much more likely to be pathogens.

Jessica Green - Engineer and biodiversity scientist
Jessica Green wants people to understand the important role microbes play in every facet of our lives: climate change, building ecosystems, human health, even roller derby -- using nontraditional tools like art, animation and film to help people visualize the invisible world. Full bio

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Humans in the developed world
00:15
spend more than 90 percent of their lives indoors,
00:17
where they breathe in and come into contact
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with trillions of life forms invisible to the naked eye:
00:23
microorganisms.
00:26
Buildings are complex ecosystems
00:28
that are an important source
00:30
of microbes that are good for us,
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and some that are bad for us.
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What determines the types and distributions
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of microbes indoors?
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Buildings are colonized by airborne microbes
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that enter through windows
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and through mechanical ventilation systems.
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And they are brought inside
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by humans and other creatures.
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The fate of microbes indoors
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depends on complex interactions
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with humans,
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and with the human-built environment.
01:00
And today, architects and biologists
01:02
are working together
01:04
to explore smart building design
01:06
that will create
01:09
healthy buildings for us.
01:11
We spend an extraordinary amount of time
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in buildings
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that are extremely controlled environments,
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like this building here --
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environments that have mechanical ventilation systems
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that include filtering,
01:26
heating and air conditioning.
01:28
Given the amount of time that we spend indoors,
01:30
it's important to understand
01:32
how this affects our health.
01:34
At the Biology and the Built Environment Center,
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we carried out a study in a hospital
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where we sampled air
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and pulled the DNA
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out of microbes in the air.
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And we looked at three different types of rooms.
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We looked at rooms that were mechanically ventilated,
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which are the data points in the blue.
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We looked at rooms that were naturally ventilated,
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where the hospital let us turn off the mechanical ventilation
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in a wing of the building
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and pry open the windows
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that were no longer operable,
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but they made them operable for our study.
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And we also sampled the outdoor air.
02:08
If you look at the x-axis of this graph,
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you'll see that what we commonly want to do --
02:13
which is keeping the outdoors out --
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we accomplished that with mechanical ventilation.
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So if you look at the green data points,
02:21
which is air that's outside,
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you'll see that there's a large amount of microbial diversity,
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or variety of microbial types.
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But if you look at the blue data points,
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which is mechanically ventilated air,
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it's not as diverse.
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But being less diverse
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is not necessarily good for our health.
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If you look at the y-axis of this graph,
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you'll see that, in the mechanically ventilated air,
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you have a higher probability
02:47
of encountering a potential pathogen,
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or germ,
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than if you're outdoors.
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So to understand why this was the case,
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we took our data
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and put it into an ordination diagram,
03:00
which is a statistical map
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that tells you something
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about how related the microbial communities are
03:06
in the different samples.
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The data points that are closer together
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have microbial communities that are more similar
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than data points that are far apart.
03:15
And the first things that you can see from this graph
03:17
is, if you look at the blue data points,
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which are the mechanically ventilated air,
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they're not simply a subset of the green data points,
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which are the outdoor air.
03:27
What we've found is that mechanically ventilated air
03:29
looks like humans.
03:32
It has microbes on it
03:34
that are commonly associated with our skin
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and with our mouth, our spit.
03:39
And this is because
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we're all constantly shedding microbes.
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So all of you right now
03:45
are sharing your microbes with one another.
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And when you're outdoors,
03:49
that type of air has microbes
03:51
that are commonly associated with plant leaves and with dirt.
03:53
Why does this matter?
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It matters because the health care industry
03:58
is the second most energy intensive industry
04:00
in the United States.
04:03
Hospitals use two and a half times
04:05
the amount of energy as office buildings.
04:07
And the model that we're working with
04:10
in hospitals,
04:12
and also with many, many different buildings,
04:14
is to keep the outdoors out.
04:16
And this model
04:18
may not necessarily be the best for our health.
04:20
And given the extraordinary amount
04:23
of nosocomial infections,
04:25
or hospital-acquired infections,
04:27
this is a clue that it's a good time
04:30
to reconsider our current practices.
04:32
So just as we manage national parks,
04:35
where we promote the growth of some species
04:38
and we inhibit the growth of others,
04:40
we're working towards thinking about buildings
04:43
using an ecosystem framework
04:46
where we can promote the kinds of microbes
04:48
that we want to have indoors.
04:51
I've heard somebody say
04:55
that you're as healthy as your gut.
04:57
And for this reason, many people eat probiotic yogurt
04:59
so they can promote a healthy gut flora.
05:02
And what we ultimately want to do
05:05
is to be able to use this concept
05:07
to promote a healthy group
05:10
of microorganisms inside.
05:12
Thank you.
05:14
(Applause)
05:16

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Jessica Green - Engineer and biodiversity scientist
Jessica Green wants people to understand the important role microbes play in every facet of our lives: climate change, building ecosystems, human health, even roller derby -- using nontraditional tools like art, animation and film to help people visualize the invisible world.

Why you should listen

Jessica Green, a TED2010 Fellow and TED2011 Senior Fellow, is an engineer and ecologist who specializes in biodiversity theory and microbial systems. As a professor at both the University of Oregon and the Santa Fe Institute, she is the founding director of the innovative Biology and the Built Environment (BioBE) Center that bridges biology and architecture.

Green envisions a future with genomic-driven approaches to architectural design that promote sustainability, human health and well-being. She is spearheading efforts to model buildings as complex ecosystems that house trillions of diverse microorganisms interacting with each other, with humans, and with their environment. This framework uses next-generation sequencing technology to characterize the “built environment microbiome” and will offer site-specific design solutions to minimize the spread of infectious disease and maximize building energy efficiency.

The original video is available on TED.com
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