Quality of the air you breathe indoors linked to your cognitive performances

Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance

indoor-pollution image
Studies suggest that indoor exposure to carbon dioxide can impair performance and decision-making. The findings pose troubling questions for people in many indoor environments, including schools, airplanes, autos and even homes.

ABSTRACT

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, EHP DOI:10.1289/ehp.1510037, October 2015.

Background
The indoor built environment plays a critical role in our overall well-being, both due to the amount of time we spend indoors (~90%) and the ability of buildings to positively or negatively influence our health. The advent of sustainable design or green building strategies reinvigorated questions regarding the specific factors in buildings that lead to optimized conditions for health and productivity.

Objective
To simulate indoor environmental quality (IEQ) conditions in “Green” and “Conventional” buildings and evaluate the impacts on an objective measure of human performance – higher order cognitive function.

Methods
Twenty-four (24) participants spent 6 full work days (9 a.m. – 5 p.m.) in an environmentally controlled office space, blinded to test conditions. On different days, they were exposed to IEQ conditions representative of Conventional (high volatile organic compound (VOC) concentration) and Green (low VOC concentration) office buildings in the U.S.
Additional conditions simulated a Green building with a high outdoor air ventilation rate (labeled Green+) and artificially elevated carbon dioxide (CO2) levels independent of ventilation.

What scientists are discovering about the air you breathe indoors, washingtonpost, February 29 2016.

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.
Conclusions: Cognitive function scores were significantly better in Green+ building conditions compared to the Conventional building conditions for all nine functional domains. These findings have wide ranging implications because this study was designed to reflect conditions that are commonly encountered every day in many indoor environments.

Economic, Environmental and Health Implications of Enhanced Ventilation in Office Buildings, mdpi, 2015

Discussion
The health benefits associated with enhanced ventilation rates far exceed the per-person energy costs relative to salary costs. Environmental impacts can be mitigated at regional, building, and individual-level scales through the transition to renewable energy sources, adoption of energy efficient systems and ventilation strategies, and promotion of other sustainable policies.

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