UNIVERSIDAD POLITÉCNICA DE MADRID ESCUELA TÉCNICA SUPERIOR DE ARQUITECTURA
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federico soriano Textos 2014-2015
14 The carbon dioxide trapped in your meeting is making you think more slowly. JOSEPH STROMBERG http://www.vox.com/2014/8/6/5971187/carbon-dioxide-indoors-air-pollution
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If, after sitting for hours in a stuffy, crowded meeting room or classroom, you’ve found yourself thinking a little more slowly than usual, it may not have been your imagination.
and engineers need to prioritize indoor air quality if they want to put students or workers in a position to succeed. “Codes need to be in place, and they need to be enforced,” he says.
An emerging body of research is indicating that the high levels of car-
“And people who design buildings need to have the awareness to construct ones
bon dioxide and other indoor pollutants that we face in poorly ventilated rooms
that are healthier for people to spend time in. To really solve the problem, all par-
reduces our cognitive performance and decision-making ability.
ties need to be involved.”
A study published in 2012 by researchers at the Lawrence Berkeley Na-
Of course, most of us aren’t architects: we’re the people who spend so
tional Laboratory found that levels of carbon dioxide commonly found in crowded
much time sitting in stuffy workspaces and classrooms. In the meantime, we may
rooms decreased people’s performance on decision-making tests, and ongoing
not be able to redesign these buildings — but the next time you’re part of a stuffy,
work at that and other labs has found that many other volatile organic compounds
unproductive meeting that’s dragging on endlessly, you can use all this research
(VOCs) — emitted in slight quantities by building materials and even personal
as a great reason to end it.
care products — also play a role. “I see this as a significant issue,” says William Fisk, the researcher who’s
Joseph Stromberg on August 6, 2014, 9:10 a.m.
led much of the work. “And for carbon dioxide in particular, it’s been really surprising to see such a strong detrimental effect.” All this research is in its early stages, and other labs are still checking to see if it can be consistently replicated. But a growing amount of evidence suggests that poor ventilation may be affecting the thinking skills of students and office workers to a far greater degree than previously thought. What researchers thought they knew about indoor pollutants Over the past few decades, a number of different studies have shown that in indoor spaces with poor ventilation, people’s cognitive abilities — whether office workers’ ability to proofread and add numbers or call center workers’ performance on talking tasks — suffer. Initially, researchers blamed VOCs or other pollutants. “We’ve known for a long time that higher carbon dioxide levels were statistically correlated with reduced performance,” Fisk says. “But we assumed it was a proxy for other pollutants that varied with ventilation rates. That’s basically been the dogma.” It’s well-known that carbon dioxide can cause detrimental physical effects at extremely high levels: at 100,000 parts per million, for instance, it can cause unconsciousness, and even higher levels can lead to death. But no one had specifically considered the effect of carbon dioxide at high but environmental2
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would affect not only carbon dioxide levels, but the levels of VOCs emitted by
ly relevant levels — say, 3,000 ppm, a concentration frequently found in crowded
individual people — and found greater declines in performance than with carbon
places like elementary school classrooms.
dioxide alone elevated.
That changed with a small study published in 2012 by researchers from
One thing that’s unclear, though, is which types of VOCs are most impor-
Budapest University of Technology and Economics. They found spending a few
tant. In most scenarios, they individually exist at very low levels, and researchers
hours in a chamber with carbon dioxide concentrations elevated to 3,000 ppm
hypothesize it may be the combination of different VOCs that affect thinking skills,
made it more difficult for people to concentrate. “That really caught our attention,”
but it still needs to be tested.
Fisk says.
What can be done to improve indoor air quality.
How carbon dioxide may affect thinking and decision making
For both carbon dioxide and VOCs, there are regulations in place that
The study led Fisk and other Berkeley lab scientists to conduct research
govern indoor air quality — but in both cases, they’re aimed at preventing the
evaluating how a few different carbon dioxide concentrations — 600, 1,000, and
much higher concentrations of the pollutants known to cause physiological prob-
2,500 ppm — affected decision-making. Working with Usha Satish, a psychiatry
lems, rather than these lower levels that may simply cause us to think a bit more
researcher at SUNY Upstate Medical University, they put 22 participants in an
slowly.
office-sized chamber and subjected them to each of the three carbon dioxide Fisk, for one, thinks that stricter indoor air quality regulations, in terms
of ventilation, are merited. But even beyond that, he says, enlightened architects
(FREDERICK FLORIN/AFP/GettyImages)
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concentrations for 2.5 hours each. They also had the participants take something called the Strategic Man-
(Jeff Hutchens/Getty Images)
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agement Simulation, a test that gives people hypothetical scenarios and asks
Levels in the majority of offices, Fisk says, are generally below 1,000 parts per
them to plan an appropriate response, then grades them in a variety of factors:
million, but he’s found that in a crowded conference room, concentrations can
basic activity, applied activity, focused activity, task orientation, initiative, informa-
climb quickly and break through this threshold within a half hour or so. He’s es-
tion orientation, information usage, breadth of approach and strategy. The idea
pecially concerned about schools: one survey, for instance, found that 21 percent
is that this sort of test, which considers more complex thinking skills, is more of a
of elementary schools in Texas had carbon dioxide concentrations above 3,000
realistic indicator of a person’s workplace productivity than, say, proofreading or
ppm.
arithmetic ability.
Now, Fisk and the other researchers caution that these findings need to
Satish had previously used this test to measure the effect of things like
be replicated. Both this and the Hungary study both had small sample sizes, and
prescription drugs and alcohol — and she and the other researchers were sur-
looked at the effects of carbon dioxide at lower levels that no one ever had before.
prised to find that the impact of 2,500 parts per million of carbon dioxide was
But if ongoing replication projects elsewhere do show the same results, this could
roughly equivalent to a .08 blood alcohol concentration, the legal limit for driving
be a very legitimate real-world problem, impacting office workers’ ability to think
in most states.
clearly during long, stuffy meetings and students’ ability to learn and perform to
“We found some pretty dramatic results,” Satish says. “People had a lot
their full potential on tests.
more difficulty taking initiative, staying oriented to a task, thinking strategically and managing information usefully. People’s abilities to make high quality decisions
How other indoor pollutants may impact our thinking too
seemed to be compromised.” How common is 2,500 parts per million carbon dioxide in the real world?
All this research, though, doesn’t let VOCs off the hook. Like carbon dioxide, it’s long been known that they cause physiological problems at higher levels, and recent work by these scientists and others has found that at lower thresholds, they likely affect decision-making as well. VOCs can come from a number of different sources. For the first few days after paint is applied, it emits slightly higher levels of them, and Satish has found that putting people in a freshly painted room causes their performance on the same test to diminish as well. VOCs can also be emitted by building materials — again in highest quantities when buildings are new — and potentially by computers and other electronics. “For our latest study, which we haven’t yet published, we had levels of organic pollutants that would be relatively typical of an office that had been renovated within the past year or so,” Fisk says. “And again, we saw cognitive declines.” Other experiments at Berkeley have even raised the possibility that VOCs emitted in slight amounts by people’s clothing and personal care products
In most categories, 2,500 ppm of carbon dioxide led to statistically significant decreases in performance. (Satish et. al., Environmental Health Perspectives)
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like shampoo and perfume may affect cognitive performance. In one study, Fisk and other researchers varied the chamber’s ventilation rate per person — which 5