Muscle Oxygenation and Performance during Low Level Carbon Monoxide Exposure

Abstract

Carbon monoxide (CO) is a toxic, odourless, colourless gas that can cause profound physiological disturbances, even at low concentrations. At low levels of approximately 5% carboxyhemoglobinemia (COHb), selective increases in blood flow to vital organs occur (Stewart, 1975). At approximately 15% COHb, people may develop frontal headaches and experience abnormal visual responses. Further, increases to 20–30% COHb result in a throbbing headache, nausea, and abnormal fine manual dexterity (Stewart, 1975). COHb levels can increase to 10–25% in people who are heavy smokers, when working in underground garages, during exposure to high traffic-congested areas in large cities (especially on a hot, humid day with low cloud cover) and during confinement in military tanks.