It's tempting to conclude from the climate change debate that all that carbon dioxide in the air is making everybody dumber.
In fact, all that carbon dioxide in the air is making everybody dumber.
Workers showed diminished cognitive functioning after spending several hours in office air that had normal levels of CO2 and chemical pollutants and ordinary ventilation, in a study published this week in Environmental Health Perspectives. Researchers tinkered with the levels of carbon dioxide and volatile organic compounds (airborne chemicals) and the amount of outside air pumped in, while the subjects did their regular work, though at a Syracuse University lab. The levels were chosen to simulate the indoor environment of conventional offices, LEED Platinum "green" buildings, and green buildings with an elevated outdoor ventilation rate ("Green+"). The 24 participants, including architects, engineers, and marketing professionals, were exposed to different conditions on different days during the six-day study, not knowing of the changes.
At 3 pm every day, the researchers administered computer-based cognitive tests of strategy-setting and focus, for example, and recorded the results and the kind of air the participants had been breathing. A day spent in the air of an extra-ventilated green building correlated with the best performance on the tests. Participants performed 61 percent better in green-building air than in conventional air, and 101 percent higher in the Green+ scenario. The research was supported in part by a United Technologies gift to Harvard's T.H. Chan School of Public Health. United Technologies, which makes building systems, wasn't involved in the experiment itself.
On one of the tests, which gauged cognitive performance in a crisis, people in the green scenario tested 97 percent better than in a conventional office environment. Participants in the Green+ air tested 131 percent better in a crisis.
Office air is a trade-off between quality and cost. Treating air takes a lot of energy, which doesn't come cheap. Indoor air is bad partly because we're getting thriftier in our use of energy.
The good news, according to lead author Joseph G. Allen of Harvard's public health school, is that improving the levels of CO2, volatile organic chemicals, and ventilation is good for employees, good for business, and relatively simple. "When you optimize all three of these" air-quality variables, Allen said, "the result is a doubling of the cognitive score." A $30 per worker investment in extra energy costs yields a $6,000 annual productivity improvement, he said.
Research for a sequel to the study has already been conducted, and the results are expected within a couple of months. They will show how cost-effective it is to improve office air.
Meanwhile there are always plants.
If only cleaning the air outside were as straightforward.