Which effect does carbon monoxide have on human health?

Carbon monoxide is a colorless, odorless gas produced by the incomplete combustion of carbon-containing fuels. When inhaled, it binds to hemoglobin in the blood more effectively than oxygen, leading to a decrease in the body's ability to transport oxygen. This reduction in oxygen delivery can contribute to the deterioration of lung function, which is especially harmful for individuals with pre-existing respiratory conditions or those who are exposed to it in high concentrations. Symptoms of carbon monoxide exposure can include headaches, dizziness, weakness, confusion, and in severe cases, can lead to loss of consciousness or death.

The other options do not accurately reflect the impact of carbon monoxide on health. It does not boost the immune system, enhance cognitive performance, or have no effect on health; rather, its exposure poses significant risks to respiratory and overall health.