Carbon Monoxide

( Article Type: Explanation )

Carbon monoxide is a colourless gas produced by incomplete combustion, mainly from motor vehicles and cigarettes. It is found naturally in the atmosphere in minute quantities. Carbon monoxide is toxic because it combines with haemoglobin (the red blood pigment) to form pink carboxyhaemoglobin, which prevents the blood from performing the function of transporting oxygen to body tissues.

The natural levels of carbon monoxide in the blood are around 0.5%. Levels in a driver sitting in dense traffic may rise to 2%, smokers may have levels of between 4 and 8% and chain smokers may achieve 9 to10%. At these levels, no permanent harm is known of, except in people with heart or lung complaints. However, higher concentrations can be fatal.