A team of researchers from the Environmental Energy Technologies Division and State University of New York—Upstate Medical University has found that increasing indoor carbon dioxide concentrations at the higher end of the range typically measured in buildings, 1,000 parts per million, and 2,500 ppm, can reduce human decision-making performance.
Relative to a concentration 600 ppm in a well-ventilated building, at 1,000 ppm CO2, moderate and statistically significant decrements occurred in six of nine scales of decision-making performance. At 2,500 ppm, large and statistically significant reductions occurred in seven scales of decision-making performance
In previous research, associations of higher indoor carbon dioxide concentrations with impaired work performance, increased health symptoms, and poorer perceived air quality have been attributed to other indoor air pollutants whose concentrations closely correlate with indoor CO2 with concentrations. Consequently many studies of indoor air quality use carbon dioxide concentration as a proxy for the concentrations of an array of other indoor air pollutants.
This study assessed the direct effects of CO2, within the range of indoor concentrations, on decision-making, and suggests that carbon dioxide itself can have impacts on human performance.
The authors write: "the findings of this study, if replicated, would have implications for the standards that specify minimum ventilation rates in buildings, and would also indicate the need to adhere more consistently to the existing standards."
Satish, U., Mendell, M.J., Shekhar, K., Hotchi, T., Sullivan, D., Streufert, S., Fisk, W.J., et al. "Is CO2 an Indoor Pollutant? Direct Effects of Low-to-Moderate CO2 Concentrations on Human Decision-Making Performance". Environ Health Perspect. doi:10.1289/ehp.1104789