Good IAQ improves workers’ response

USA: Improved indoor environmental quality doubled participants’ scores in cognitive function tests, according to a new study.

The Impact of Green Buildings on Cognitive Function study, carried out by researchers at Harvard University TH Chan School of Public Health’s Center for Health and the Global Environment, SUNY Upstate Medical University and Syracuse University, found that employees’ cognitive performance scores averaged 101% higher in green building environments with enhanced ventilation compared to a conventional building environment. Green office buildings were defined as those with low VOC concentrations.

Primary support for the study came from United Technologies and its UTC Climate, Controls & Security business.

“We know green buildings conserve natural resources, minimise environmental impacts and improve the indoor environment, but these results show they can also become important human resource tools for all indoor environments where cognitive abilities are critical to productivity, learning and safety,” said John Mandyck, UTC’s chief sustainability officer. “When it comes to the decision-making ability of green building occupants, intelligence is in the air.”

“The payback for improved indoor environmental quality far outweighs the investment, considering that more than 90% of the costs associated with a building are related to the people who work within it once construction is completed,” he added.

The double-blind study evaluated the cognitive performance of 24 participants who experienced conditions in a laboratory setting that simulate those found in conventional and green buildings, as well as green buildings with enhanced ventilation. Researchers measured cognitive function for nine functional domains, including basic, applied and focused activity levels; task orientation; crisis response; information seeking; information usage; breadth of approach; and strategy.

The largest improvements in cognitive function test scores occurred in the areas of crisis response, information usage and strategy. Crisis response scores were found to be 97% higher for the green environment and 131% higher for the green environment with enhanced ventilation and lower carbon dioxide levels compared to the conventional environment.

Information usage scores for green and enhanced green environments were 172% and 299% higher than in the conventional environment, respectively. For strategy, green and enhanced green scores were 183% and 288% higher than the conventional environment.

“This study suggests that indoor environments can have a profound impact on the decision-making performance of workers, which is a primary indicator of worker productivity,” said Dr Joseph Allen, assistant professor of exposure assessment science at the Harvard TH Chan School of Public Health, director of the Healthy Buildings Programme at the Center for Health and the Global Environment at Harvard Chan School, and principal investigator for the study. “These results are provocative for three reasons. First, they suggest that the levels of carbon dioxide and volatile organic compounds that we commonly encounter in conventional office buildings are associated with decreases in worker performance compared to when those same workers are in green building environments. Second, when we enhance ventilation and optimise indoor environmental conditions, we see improvements in the cognitive function of workers. And third, these results fill important knowledge gaps in existing research about the relationship between green buildings and occupant health.”

The full report is available at here.