FAA Ground School Practice Test

As altitude increases, what happens to susceptibility to carbon monoxide poisoning?

1. It decreases

2. It remains the same

3. It increases

4. It becomes negligible

The correct answer is: It increases

As altitude increases, susceptibility to carbon monoxide poisoning increases due to a combination of factors related to atmospheric pressure and the body's ability to transport oxygen. At higher altitudes, the partial pressure of oxygen decreases, which can impair the body's ability to effectively utilize oxygen. When carbon monoxide is present, it competes with oxygen for binding sites on hemoglobin in the blood. This competition becomes more critical at high altitudes because the reduced availability of oxygen means that the body is already under stress to get sufficient oxygen. Consequently, even small amounts of carbon monoxide can lead to more significant physiological effects, increasing the risk of poisoning. In addition, the reduced atmospheric pressure at higher altitudes causes the concentration of gases, including carbon monoxide, to be less dispersed, potentially leading to greater exposure. Therefore, the overall risk and susceptibility to the effects of carbon monoxide poisoning increases as altitude rises.