How does air quality affect cognition?

Is the quality of the air you are breathing affecting your cognitive abilities? How sensitive is your mind to elevated CO2 levels? Previous studies on CO2 exposures (according to the 2012 journal article described below) found that breathing high CO2 concentrated air could increase partial pressure and change a person's respiration, cerebral blood flow, cardiac output and anxiety level. The two studies below are a foray into the idea that high CO2 concentrated air levels--perhaps brought on by these physiological changes--may have negative effects on worker productivity.

The 2012 study implies that poor air quality negatively affects people's performance at work and may affect some people more strongly than others. It compared cognitive scores in 9 categories (as listed above) at different CO2 levels: 600ppm, 1000ppm and 2500ppm. The participants were unaware of what was changing about their environment. In 7 of the 9 categories, the raw scores consistently decreased as CO2 level increased. Note that while extremely high, the 2500ppm occurs in indoor environments even today: surveys of elementary school classrooms in California and Texas found "a substantial proportion exceeded 2,000ppm and for 21% of Texas classrooms, peak CO2 concentration exceeded 3,000ppm." To check out the full study, click here.

This study looked at not only CO2 levels, but VOC levels as well, since a green building should involve selection of low VOC containing furniture and finishes. Again the effect was evident: higher levels of CO2 and VOCs resulted in lower cognitive scores. A "green building" was defined as one with low VOC levels, while a "green+ building" was defined as one with not only low VOC levels but also higher ventilation rates. Overall scores were 61% improved for the "green building condition" as compared to the conventional building condition, 101% improved for a "green+ building" as compared to the conventional building condition. Checkout the full study here.

While the loss of ability is minor at an individual level, for employers who multiply these costs day after day and whose overall performance depends upon collective efforts of all employees, the cost could be economically significant.