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Your Environment. Your Health.

Green Office Environments Linked with Higher Cognitive Function

P. MacNaughton
Harvard School of Public Health
NIEHS Grant T32ES007069

People who work in well-ventilated offices with below-average levels of indoor pollutants and carbon dioxide showed significantly higher cognitive functioning scores than those working in offices with typical levels, according to a new study funded in part by NIEHS. The new findings suggest that improving air quality could greatly increase the cognitive performance of workers.

The double-blind study included architects, designers, programmers, engineers, creative marketing professionals, and managers who worked in a controlled office environment for six days. Participants performed their normal work while exposed to one of four simulated building conditions per day. The indoor environmental quality conditions were conventional with relatively high concentrations of volatile organic compounds (VOCs); green conditions with low VOC concentrations; green conditions with enhanced ventilation; and conditions with artificially elevated levels of carbon dioxide, independent of ventilation. At the end of each day, participants underwent cognitive testing.

On average, cognitive scores were 61 percent higher on the days participants experienced green conditions with low VOC concentrations and 101 percent higher on the days they experienced green conditions with enhanced ventilation compared to the conventional building day (p less than 0.0001). VOCs and carbon dioxide were independently associated with cognitive scores. Measuring nine types of cognitive function, the researchers found the green conditions with low VOC and green conditions with enhanced ventilation showed the largest improvements in the areas of crisis response, strategy, and information usage.

Citation: Allen JG, MacNaughton P, Satish U, Santanam S, Vallarino J, Spengler JD. 2015. Associations of cognitive function scores with carbon dioxide, ventilation, and volatile organic compound exposures in office workers: a controlled exposure study of green and conventional office environments. Environ Health Perspect; doi:10.1289/ehp.1510037 [Online 26 October 2015].

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