Effects of Exposure to Carbon Dioxide Indoors on Human Comfort, Health and Performance

Recent experiments in the USA show that concentrations of carbon dioxide (CO2) of 2,500 ppm can negatively affect cognitive performance in particular the decision-making. They suggest that CO2 should be considered as the unwanted pollutant at concentrations likely to occur indoors. CO2 is a human metabolite, thereby its main source indoors are humans. The indoor concentrations of CO2 are between 400 ppm, which is a typical outdoor concentration, and 5,000 ppm, which is an occupational exposure limit. CO2 is normally used as the indicator of poor air quality and the adequacy of ventilation in spaces occupied by humans. Concentrations below 1,000 ppm have been considered to indicate acceptable indoor air quality.