Question

Which of the following air pollutants reduces the oxygen-carrying capacity of blood?

• A. Carbon dioxide
• B. Carbon monoxide
• C. Sulphur dioxide
• D. Nitrogen dioxide

Answer 1

The correct option is B

Carbon monoxide

• 
  Carbon monoxide can bind to haemoglobin (240 times more tightly than oxygen), forming a compound called carboxyhaemoglobin. This means that if carbon monoxide and oxygen are inhaled, carbon monoxide will preferentially bind to haemoglobin.
• This reduces the amount of haemoglobin available to bind with oxygen, so the body and tissues become starved of oxygen.