Question

In blood, carboxyhaemoglobin is formed by

• A. Inhalation of CO
• B. Inhalation of $C{O}_2$
• C. Inhalation of $S{O}_2$
• D. Inhalation of Ozone

Answer 1

The correct option is A Inhalation of CO

Carbon monoxide is a poisonous gas released during the incomplete combustion of fossil fuels. It has greater affinity for haemoglobin than oxygen. When it is inhaled, CO binds to haemoglobin to form carboxyhemoglobin, which is about 300 times more stable than the oxygen-hemoglobin complex. When the concentration of carboxyhemoglobin reaches about 3–4 percent, the oxygen carrying capacity of blood is greatly reduced which may lead to fatal.