Carbon monoxide poisoning
Risk factors for ongoing effects from poisoning
Ongoing symptoms and effects from carbon monoxide poisoning is a risk for anyone that has been
exposed to unsafe levels of carbon monoxide.
People respond differently to the same level of exposure. The relationship between symptoms, carboxyhemoglobin
(COHb) in the bloodstream, levels of carbon monoxide in the air, and ongoing effects is
Symptoms and after effects of poisoning can range from mild to severe in people with the same level of
However, the following factors may increase the likelihood of short term symptoms and effects and long term effects caused by poisoning damage:
- The length of time high levels of carbon
monoxide remain in the body/bloodstream.
- The higher the level of carbon monoxide in the
- Anyone exposed multiple times to low levels of carbon monoxide (chronic CO poisoning).
- Someone engaged in higher levels of physical activity while breathing unsafe levels of carbon monoxide
(someone doing physical work, exercising, or if the poisoning itself triggered physical convulsions).
- A person resuscitated from unconsciousness due to CO poisoning.
- A person knocked or rendered unconsciousness one or more times prior to carbon monoxide poisoning.
- Anyone physically vulnerable and less able to recover: infants, elderly, sick, heavy smokers.
- If a woman is pregnant, the fetus is at higher risk of effects from carbon monoxide poisoning. It takes
longer to eliminate carbon monoxide from the fetus's blood than from the mother's blood.
- People with a history of: circulatory problems, respiratory problems, heart disease, anaemia, cellular weakness, weak constitution, concussions, or brain injury.
- Carbon monoxide poisonings have been lethal for people with [severe] heart disease at levels of 10 to 30%
in the blood, while lethal poisonings are typically 50 to 60% and higher.
- Carbon monoxide in cigarettes and tobacco smoke causes
smokers to have above average levels of carbon monoxide
in their blood stream. Smokers are at higher risk of more severe symptoms and ongoing effects.
- Altitude. The higher the altitude, the less oxygen in the air to compete with the carbon monoxide.
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term effects or top of Risk factors
for ongoing effects from carbon monoxide poisoning