Effects of Smoking

Carbon monoxide is a colourless, odourless, tasteless gas that is a product of incomplete combustion. Haemoglobin, the oxygen-carrying chemical in the blood, picks up carbon monoxide over 200 times more readily than it picks up oxygen. Thus, even minute quantities in the cockpit (often from improperly vented exhaust fumes) may result in pilot incapacitation.

The symptoms of carbon monoxide poisoning are insidious. Initially, there is an inability to concentrate, thinking becomes blurred, and subsequently dizziness and headache develop. If any of these symptoms are noticed, pilots should turn off the heater, open the air ventilators and descend to a lower altitude if it is safe to do so. If oxygen is available, it should be used. If an exhaust leak is suspected, the pilot should land the aircraft as soon as possible.

Smoking is a source of carbon monoxide. Smokers carry some carbon monoxide in their blood all the time, and may have 5 to 10 percent of their haemoglobin saturated with carbon monoxide. This reduces the oxygen-carrying capacity of the blood and smokers may become hypoxic at altitudes below 10,000 feet ASL.