Carbon Monoxide Poisoning - Causes

Causes

Carbon monoxide is a product of combustion of organic matter under conditions of restricted oxygen supply, which prevents complete oxidation to carbon dioxide (CO₂). Sources of carbon monoxide include cigarette smoke, house fires, faulty furnaces, heaters, wood-burning stoves, internal combustion vehicle exhaust, electrical generators, propane-fueled equipment such as portable stoves, and gasoline-powered tools such as leaf blowers, lawn mowers, high-pressure washers, concrete cutting saws, power trowels, and welders. Exposure typically occurs when equipment is used in buildings or semi-enclosed spaces.

Poisoning may also occur following the use of a self-contained underwater breathing apparatus (SCUBA) due to faulty diving air compressors. Riding in pickup trucks has led to poisoning in children. Idling automobiles with the exhaust pipe blocked by snow has led to the poisoning of car occupants. Generators and propulsion engines on boats, especially houseboats, has resulted in fatal carbon monoxide exposures. As part of the Holocaust during World War II, German Nazis used gas vans to kill an estimated 700,000 prisoners by carbon monoxide poisoning. This method was also used in the gas chambers of several death camps.

Another source of poisoning is exposure to the organic solvent dichloromethane, found in some paint strippers, as the metabolism of dichloromethane produces carbon monoxide. In most light aircraft and some cars the cabin heating system comprises a shroud around the exhaust. Any perforation between the exhaust manifold and shroud can result in exhaust gases reaching the cabin. In caves carbon monoxide can build up in enclosed chambers due to the presence of decomposing organic matter.