Carbon monoxide poisoning

Carbon monoxide (CO) binds very strongly to the iron atoms in haemoglobin, the principal oxygen-carrying compound in blood. The affinity between CO and haemoglobin is 200 times stronger than the affinity between haemoglobin and oxygen.

Related Topics:
Carbon monoxide - Iron - Atom - Haemoglobin - Oxygen - Blood

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As CO binds to the haemoglobin, producing carboxyhaemoglobin, it cannot be released nearly as readily as oxygen would be.

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Thus, the body's haemoglobin becomes saturated with CO and cannot carry oxygen to the body. A sufficient exposure to carbon monoxide can reduce the amount of oxygen taken up by the brain to the point that the victim becomes unconscious, and can suffer brain damage or even death from anoxia. The brain regulates breathing based upon carbon dioxide levels in the blood, rather than oxygen, so a victim can succumb to anoxia without ever noticing anything up to the point of collapse. Haemoglobin acquires a bright red colour when converted to carboxyhaemoglobin, so a casualty of CO poisoning can look abnormally pink-cheeked and healthy.

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A major problem of accidental CO poisoning that still exists is the use of heaters, particularly gas water heaters and gas fires which are improperly vented. A number of deaths occur every year from this cause. This can occur in any enclosed area with such a heater: a home, a camper or RV, in a houseboat, etc. Other types of fuel-burning with improper ventilation can create deadly levels of CO as well: a fireplace with an obstructed chimney, burning charcoal indoors, etc. A carbon monoxide detector can be set up in homes (and other enclosed spaces with heaters) to detect a build-up of CO. If a high level of CO is detected, the detector sounds an alarm, giving people in the area a chance to ventilate the area or safely leave the building before they succumb to anoxia.

Related Topics:
Camper or RV - Fireplace - Chimney - Charcoal - Carbon monoxide detector

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CO poisoning can occur in scuba diving due to faulty or badly sited diving air compressors. See under Diving hazards and precautions#Effects of relying on breathing equipment while underwater for more information. At great depth pressure, enough oxygen to support life may dissolve in the blood plasma and thus bypass the blocked haemoglobin; the CO poisoning symptoms show when the diver comes back up to a shallower depth.

Related Topics:
Scuba - Diving air compressor - Diving hazards and precautions#Effects of relying on breathing equipment while underwater - Blood plasma

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First aid for carbon monoxide poisoning is to immediately remove the victim from the exposure without endangering oneself, call for help, apply CPR and if possible apply oxygen first aid. Hyperbaric oxygen therapy is a treatment for carbon monoxide poisoning.

Related Topics:
First aid - Call for help - CPR - Oxygen first aid - Hyperbaric oxygen therapy

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New research shows that in chronic low-level exposure, carbon monoxide acts as a potent neurotoxin, creating irreversible lesions in the brain's white matter (i.e., the myelin sheath). Such lesions, which are similar to those found in multiple sclerosis, can result in severe cognitive impairment.

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