What is the effect of carbon monoxide on the human body?

Carbon monoxide has a significant and detrimental effect on the human body by reducing the blood's ability to carry oxygen, which can lead to a condition known as hypoxia. Carbon monoxide binds to hemoglobin in red blood cells much more effectively than oxygen does, forming carboxyhemoglobin. When carbon monoxide is present, this binding limits the availability of hemoglobin to transport oxygen effectively throughout the body.

As oxygen is vital for cellular respiration and overall bodily functions, its deficiency can result in a variety of symptoms such as headaches, dizziness, weakness, confusion, and in severe cases, it can be life-threatening. The understanding of carbon monoxide's impact highlights the importance of monitoring air quality and ensuring proper ventilation, especially in enclosed spaces where combustion engines or heating systems are present. Thus, the correct answer clearly encapsulates the harmful consequences of carbon monoxide exposure.