What health effects can high levels of CO2 cause?

High levels of carbon dioxide (CO2) in indoor environments can lead to a range of negative health effects, primarily due to its impact on human physiology and brain function. When CO2 concentrations rise, they can cause symptoms such as drowsiness, headaches, and impaired cognition.

As CO2 levels increase, the amount of oxygen available in the air decreases, which can impair cognitive performance and alertness. Drowsiness arises as the body struggles to obtain sufficient oxygen, and headaches result from the body reacting to the high levels of CO2. Additionally, studies show that elevated CO2 can lead to reduced attention, decision-making abilities, and overall mental performance, making it an important factor to monitor in indoor air quality assessments.

In contrast, the other options suggest possible positive or neutral outcomes that are not supported by research. For instance, high CO2 levels do not contribute to improved concentration or increased energy; instead, they typically cause the opposite effects on brain function and physical well-being.