**2.6 Health effect of carbon monoxide**

Kinetics of carbon monoxide starts with inhalation of the pollutant and diffuses to the alveolar membrane of the lung. During a gas exchange that takes place in capillaries, the CO gas can be exchanged in the same way oxygen does. After its bioavailability in plasma, quickly binds with hemoglobin (Hb) at rate 200–300 times more than oxygen [15]. It can equivocally compete for hemoglobin binding sites with oxygen. Unlike oxygen, the bond is stronger and lasts longer. The formation of carboxyhemoglobin (COHb) makes the transport of oxygen difficult for the body system and results in a state of hypoxia. The primarily affected body organs with reduced oxygen delivery are the myocardium (muscle of the heart), brain, skeletal muscles that employ exercise, and developing fetus. At low levels, symptoms of CO exposure include fatigue, headaches, and dizziness, but in higher concentrations, it can lead to impaired vision, disturbed coordination, nausea, and eventually death.
