What is the outcome of short-term exposure to moderate concentrations of CO?

The outcome of short-term exposure to moderate concentrations of carbon monoxide (CO) typically leads to symptoms such as impaired vision and dizziness. 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, reducing the amount of oxygen available to tissues and organs.

Impaired vision occurs because CO can affect the oxygen supply to the eyes, leading to temporary visual disturbances. Dizziness is a common symptom due to reduced oxygen levels in the brain, which can impair cognitive function and balance. These effects can manifest quickly, making them a common set of symptoms associated with short-term exposure to moderate concentrations of CO.

Other options reflect symptoms that might arise either from longer-term exposure or at higher concentrations of CO. Thus, the selection of impaired vision and dizziness most accurately represents the immediate effects of moderate, short-term CO exposure.