CO2 and adolescents' cognitive and motor performance

The increasing CO2 concentration in our atmosphere is a hot topic in health, media, politics, and science. People often discuss the indirect impacts of increasing CO2 on humans, such as global warming and rising sea levels, but they only rarely discuss how CO2 directly affects our psychological functioning. A number of studies have in fact suggested that elevated CO2 levels can affect our cognitive performance (e.g., the ability to concentrate, or make decisions). So far, however, the specific level at which CO2 becomes detrimental is not yet clear. Moreover, there is a lack of evidence about the effects of CO2 on vulnerable populations, different kinds of performance (e.g., reaction speed, motor control), and the role of other air contaminants such as volatile organic compounds (VOC). We therefore investigate the effects of natural indoor CO2 and VOC concentrations (including possible interactions) in a very large sample of adolescents (N ~ 15,000 to 18,000). Adolescents spend much of their time indoors, where CO2 tends to be relatively high. Adolescents may also be particularly sensitive to the effects of CO2 because their brains are so malleable and developing so quickly. The adolescents in our study take a series of tests that measure, for example, their intelligence, spatial orientation, reaction time, and their arm, hand, and finger dexterity. While they are taking the tests, we measure the CO2, VOC, temperature, and humidity. To reliably measure the room environment, we use several miniature computers and gas sensors per room. The devices are small and quiet, so they can be discretely placed throughout the test rooms. We then analyze whether the CO2 level in the room is related to how participants score on the tests. We also analyze whether certain environmental or personal characteristics make the effects of CO2 stronger or weaker. Our results have the potential to expand discussions about the impact of rising CO2 levels for humanity.