A study by Harvard T.H. Chan School of Public Health’s Center for Health and the Global Environment, SUNY Upstate Medical University, and Syracuse University. (October 16, 2015) found that cognitive performance scores for the participants who worked in the green (low VOC) environments with a high outdoor air ventilation rate were, on average, double those of participants who worked in conventional environments.
Measuring nine cognitive function domains, researchers found that the largest improvements occurred in the areas of:
- crisis response (97% higher scores in green conditions and 131% higher in green+)
- strategy (183% and 288% higher)
- information usage (172% and 299% higher)
In another study by Harvard T.H.Chan School of Public Health, when researchers looked at the effect of CO2 — not normally thought of as a direct indoor pollutant—they found that, for seven of the nine cognitive functions tested, average scores decreased as CO2 levels increased from 600 ppm (CO2 levels with good ventilation) to 950 ppm (CO2 levels commonly observed in many indoor environments).
This Harvard University study estimated that the productivity benefits from doubling the ventilation rates are $6,500 per person per year. This does not include the other potential health benefits, such as reduced sick building syndrome and absenteeism.
“We have been ignoring the 90%. We spend 90% of our time indoors and 90% of the cost of a building are the occupants, yet indoor environmental quality and its impact on health and productivity are often an afterthought,” said Joseph Allen, assistant professor of exposure assessment science, director of the Healthy Buildings Program at the Harvard Center for Health and the Global Environment, and lead author of the study. “These results suggest that even modest improvements to indoor environmental quality may have a profound impact on the decision-making performance of workers.”
High levels of CO2 (above 800 ppm) lead to slow performance, fatigue, difficulty concentrating, and impairs executive function (Allen et al. 2016)
The available scientific literature indicates the potential for a few percent to 15% increases in aspects of student performance, including and higher scores in standardized math and reading tests, with increased classroom ventilation rates.(Fisk)
A study in Denmark reported an 8% increase in speed of school work tasks with a doubling of ventilation rate (Wargocki et al.)
Ventilation rates in roughly half of U.S. public elementary school classrooms appear to be less than specified in codes (Fisk)
Increasing the ventilation rates toward recommended guideline ventilation rates in classrooms should translate into improved academic achievement of students.(Shaughnessy et al.)
- Green Office Environment linked with highher cognitive scores
- 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 (Joseph G. Allen, Piers MacNaughton, Usha Satish, Suresh Santanam, Jose Vallarino, and John D. Spengle)
- Stale Office Air Is Making You Less Productive by Joseph G. Allen
- Indoor air quality, ventilation and health symptoms in schools: an analysis of existing information. Daisey JM1, Angell WJ, Apte MG.
- The ventilation problem in schools: literature review. Indoor Air, 2017 Fisk W.J.
- Association between substandard classroom ventilation rates and students' academic achievement By Haverinen-Shaughnessy U1, Moschandreas DJ, Shaughnessy RJ