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
Published on Jun 01, 2016 by Environmental Health Perspectives
Quality Score: High
Study Quality
This study was of extremely high quality. The researchers took great effort to have proper controls in place. The human population of subjects were from diverse professional backgrounds of varying ages and not just university students. The researchers made sure to control for ambient noise and worked hard to make the study truly double-blind. There was great effort to ensure the environment the working professionals were in resembled a typical office. The study duration was over two weeks for 7 1/2 hours per day Tuesday-Thursday to control for the Monday and Friday effects. To measure cognitive behavior, the researchers used the Strategic Management Simulation (SMS) software tool, which is a validated, computer-based test that has been designed to test the effectiveness of management-level employees through assessments of higher-order decision making.
Supports Claims
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Claim
Carbon Dioxide can impair cognitive function
Research Findings - (Strength: Strong)
This study found that on average, a 400-ppm increase in CO2 was associated with a 21% decrease in a typical participant’s cognitive scores across all domains tested. This study's subjects were exposed to CO2 levels in the range of 486 - 1,420 ppm.
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Claim
Increased outdoor air ventilation rates improve cognitive function
Research Findings - (Strength: Strong)
This study compared outdoor air ventilation of 20 cubic feet per minute per person versus 40 cubic feet per minute per person. The study subjects performed 18% better on cognitive tests when in exposed to the higher ventilation rate.
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Claim
Exposure to volatile organic compounds can impair cognitive function
Research Findings - (Strength: Strong)
This study found that a 500-μg/m3 increase in volatile organic compounds (VOCs) in the indoor environment was associated with a 13% decrease in cognitive performance.
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Claim
Air pollution can impair cognitive performance
Research Findings - (Strength: Strong)
On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001).
Research Paper Facts
Results
- On average, cognitive scores were 61% higher on the Green building day and 101% higher on the two Green+ building days than on the Conventional building day (p < 0.0001).
- VOCs and CO2 were independently associated with cognitive scores.
Publishing Journal
Environmental Health Perspectives
Published On
Jun 01, 2016
Related Topics
Open Access
true
Study Type
Human
Control Method
Double Blind
Number of Study Subjects
24
Funding Sources
This research was supported by a gift from United Technologies to the Center for Health and the Global Environment at the Harvard T.H. Chan School of Public Health. J.G.A.’s time was primarily supported by faculty startup funds, J.D.S.’s time was primarily funded by his endowed chair, and P.M.’s time was supported by National Institute of Environmental Health Sciences (NIEHS) environmental epidemiology training grant 5T32ES007069-35. United Technologies Research Center provided limited input during the study design phase (support for adding a control day and adding a third CO2 test level). United Technologies was not involved in the data collection, data analysis, data interpretation, data presentation, or drafting of the manuscript.The authors declare they have no actual or potential competing financial interests。
Authors
- Joseph G. Allen,
- Piers MacNaughton,
- Usha Satish,
- Suresh Santanam,
- Jose Vallarino,
- John D. Spengler
Sponsoring Institution(s)
- Department of Environmental Health, T.H. Han School of Public Health, Harvard
- Department of Psychiatry and Behavioral Science, Upstate Medical University, State University of New York
- Industrial Assessment Center, Center of Excellence, Syracuse University