Talk:Carbon monoxide poisoning

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Good article Carbon monoxide poisoning has been listed as one of the Natural sciences good articles under the good article criteria. If you can improve it further, please do so. If it no longer meets these criteria, you can delist it, or ask for a reassessment.
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[edit] Strength of Ligands

Though CO and Cyanide are both strong ligands why do they proceed in two parallel routes in their mechanism for poisoning the human body? --Curieous 09:58, 14 October 2007

[edit] Another possible treatment for CO poisoning

I found this on the "iron" article:

Humans also use iron in the hemoglobin of red blood cells, in order to transport oxygen from the lungs to the tissues and to export carbon dioxide back to the lungs. And iron is an essential component of myoglobin to store oxygen in muscle cells.
The human body needs iron for oxygen transport. That oxygen is required for the production and survival of all cells in our bodies.

This seems like taking an iron tablet would help. -Usernamefortonyd

Maybe to combat the effects of chronic low-level exposure. Taking iron isn't going to help if most haemoglobin has been rendered useless by acute CO exposure, the body isn't going to make new haemoglobin fast enough. Also remember WP:NORM0ffx 11:09, 12 October 2007 (UTC)

Then you have to deal with the effects of iron overload as well; iron is pretty toxic (like most minerals) when outside it's normal dosage; case in point, haemochromotosis. For the treatment to be effective, the iron would need to be a form easily and quickly absorbed into the bloodstream, and capable for readily forming a stable, non-toxic complex with CO. The iron in an iron tablet is not in such a form. —Preceding unsigned comment added by (talk)

[edit] Resolving the disputed tag

I've left a message with User:Physchim62 asking him for information on the disputed tag. --Arcadian 16:58, 9 December 2005 (UTC)

The following paragraph was queried on the Reference Desk:
"With chronic low-level exposure, similar neurologic injury may occur. 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."
As with most of the article, its source is unclear; I have however managed to track down the paper, which appears to be Penney, D. G.; Verma, K.; Hull, J. A. (1989). "Cardiovascular, metabolic and neurologic effects of acute carbon monoxide poisoning in the rat". Toxicol. Lett. 45(2/3):207–13. As the title suggests, this study concerned an acute exposure in an animal model, not chronic exposure in humans.
The use of the term neurotoxin is more than ambiguous: such neurological damage may not be solely related to primary anoxia, but other animal studies suggest that secondary hypertension, secondary acidosis and elevated blood glucose levels are also involved (Penney, D. G. (1990). "Acute carbon monoxide poisoning: animal models: a review". Toxicology 62(2):123–60.)
"The effect of prolongued exposure to low levels of carbon monoxide [in humans] is still a very controversial subject. It seems however that a long term toxic effect on the cardiovascular system cannot be excluded." Institut national de recherche et de sécurité (1996). "Oxyde de carbone". Fiche toxicologique n°. 47, 6pp. (PDF, in French) And how can you discuss possible chronic effects without noting that heavy cigarette smokers have HbCO levels of 10% or over (compared to 1–2% for non-smokers in the countryside: Source Sax's Dangerous Properties of Industrial Materials)
Unfortunately, such imprecisions seem common throughout the article, which should be completely rewritten from trustable sources: I certainly don't object to being an external link, but if it is really the only source then we should just start again from scratch.
Physchim62 (talk) 10:24, 10 December 2005 (UTC)

[edit] Reduction of O2 delivery isn't often relevant?

The reduction in oxygen delivery (DO2) caused by carboxyhaemoglobin is seldom relevant, but often quoted as the mechanism of the observed tissue hypoxaemia. For example, if total Hb is 15 g/dL and CarboxyHb is 33%, then this still leaves 10 g/dL of normal OXYHAEMOGLOBIN. So at worst, CO poisoning has caused a mild functional anaemia. This can hardly be responsible for tissue hypoxia to any degree. Whilst it is true that the P50 of this oxyhaemoglobin is left shifted, this has a minor effect in the context of tissue acidosis which mostly overcomes it. The principal mechanism of tissue hypoxia is poisoning of cytochrome oxidase, with failure of electron transport and reduction of molecular O2. The value of measuring Carboxyhaemoglobin is that it merely serves as a useful marker of exposure to CO.


I personaly think a section describing the symptoms of carbon monoxide poisoning would enhance this article.

Yes. Also, some information on prognosis. How fast do the symptoms of minor poisoning fade with time (or do they), what treatments are used, and how effective are they?--Srleffler 23:07, 12 February 2006 (UTC)
I can answer this from experience, as I used to work with the stuff and suffered minor poisoning on a couple of occasions. First symptoms are lethargy and/or a headache. Treatment is to remove the source of intoxication (I used to take myself off home for the afternoon), recovery is complete within hours. I'll see if I can come up with more citable sources for the article. Physchim62 (talk) 00:21, 13 February 2006 (UTC)

Recommeded reading: Henry CR et al: Myocardial injury and long-term mortality following moderate to severe carbon monoxide poisoning. JAMA 2006; 295: 398-402.

[edit] CO and heart disase

Missing from this article seems to be a discussion of the link between CO and heart disease. --Badger151 19:56, 16 April 2006 (UTC)

Is this painless?

[edit] Carbon Monoxide toxicity

Should the term carbon monoxide toxicity redirect to this site?

Does Carbon Monoxide poisoning have any relation to cancer? Such as Bladder Cancer or Lung Cancer?

There appears to be a contradiction of facts or at least a begging explanation, as to why in the section labeled "Sources" it lists undiluted cigarette smoke as having 30,000 ppm YET, in the section "Toxicity" a concentration of 12,800 ppm results in unconsciousness after 2-3 breaths. So, why aren't more smokers falling over unconscious? I think there is an exaggeration of some kind in one of the two places.

Here is an article that says cigarette smokers exhale between 10-50ppm of Carbon Monoxide. Carbon Monoxide in Cigarette Smoke

At the very least, the statement that undiluted cigarette smoke has 30,000 ppm of Carbon Monoxide is misleading and should be removed unless it is explained or justified. —Preceding unsigned comment added by (talk) 19:45, 26 October 2008 (UTC)

[edit] Out of place

Smething seems out of place here

Because carbon monoxide binds to haemoglobin several hundred times more strongly than oxygen, its effects are cumulative and long-lasting, causing oxygen starvation throughout the body. Prolonged exposure to fresh air (or pure oxygen) is required for the CO-tainted hemoglobin (carboxyhaemoglobin) to clear. Carbon monoxide detectors for homes are now readily available and are increasingly being required by municipal building codes.

The last sentence seems very out of place and I think it should be moved to a different section (I tihnk it is already mentioned somewhere else anyway).Father Time89 05:10, 7 November 2006 (UTC)

[edit] Palladium compounds

"The carbon monoxide can be easily detected by the filtering paper impregnated by the solution of the palladium chloride. Carbon monooxide reduces the palladium monoxide to the black metallic palladium. This reaction is very sensitive."

Well, which one is it? The oxide or the chloride? —The preceding unsigned comment was added by MikaelRo (talkcontribs) 19:09, 6 December 2006 (UTC). --MikaelRo 19:11, 6 December 2006 (UTC)

[edit] Carbon Monoxide Poisoning - Long Term Effects

The long-term effects of Carbon Monoxide poisoning seems to have been left out of the general Carbon Monoxide catagory. One might survive CM poisoning but what then? The University of Kentucky did a study on this and found that men my experience impotence and women may experience premature sexual aging. Cardiovascular disease and Parkinson's disease have also been cited. When a person is CM poisoned it's the equivalent if being at the bottom of a lake with no air except that this time it is being caused by a poison. Linda Dohse 00:51, 19 January 2007 (UTC)

[edit] Hb tetramer effect

In the "Toxic mechanism" section under "Hemoglobin" the article says:

Because hemoglobin is a tetramer with four oxygen binding sites, binding of CO at one of these sites also increases the oxygen affinity of the remaining 3 sites, which interferes with normal release of oxygen. This causes hemoglobin to retain oxygen that would otherwise be delivered to the tissue.

How does that cause–effect relationship work? Seems like a CO molecule would knock one iron of the four out-of-play, having no effect on the other three. The statement gives a cite of PMID 12679050, but I don't see any discussion of Hb tetramers or of enhanced Hb affinity for O2 during CO exposure in that article. DMacks 17:41, 11 April 2007 (UTC)

The binding CO to a haem iron atom causes the haemoglobin chain to distort. Because a haemoglobin molecule is a tetramer, the distortion of one protein chain will cause distortions in the other chains, which prevents the release of oxygen. —Preceding unsigned comment added by (talk)

[edit] Real-world concentrations

Please add some real-world concentration numbers, typical CO ppm ranges:

- 00:20, 24 August 2007 (UTC)

"Several natural sources of CO of both biological origins have also been identified but their contributions to urban atmospheric concentrations are thought to be small. Background levels of CO (resulting from natural and technological sources) found in relatively unpolluted air range from 0.025 to 1.0 ppm. Urban carbon monoxide is produced primarily by motor vehicles.

Because motor vehicle traffic is the major source of CO, daily concentration peaks coincide with morning and evening rush hours. The worst carbon monoxide problems are found where large numbers of slow moving cars congregate. These problems are further aggravated when they occur in a "street canyon" situation. When there are large amounts of slow moving traffic in a street canyon situation, with the wind blowing perpendicular to the street, carbon monoxide can be trapped in the canyon and build up to unhealthful levels.

CO problems are usually worse in winter because: 1) cold weather makes motor vehicles run dirtier and requires more combustion for space heating; and 2) on winter nights a strong inversion layer develops in the atmosphere, that traps pollution near the ground, preventing it from mixing with cleaner air above."[1]

"No standards for CO have been agreed upon for indoor air. The U.S. National Ambient Air Quality Standards for outdoor air are 9 ppm (40,000 micrograms per meter cubed) for 8 hours, and 35 ppm for 1 hour." "Average levels in homes without gas stoves vary from 0.5 to 5 parts per million (ppm). Levels near properly adjusted gas stoves are often 5 to 15 ppm and those near poorly adjusted stoves may be 30 ppm or higher."[2]

"undiluted cigarette smoke contains about 30,000 ppm of CO, undiluted warm car exhaust about 7,000 ppm, and the chimney of a home wood fire about 5,000 ppm. Clean countryside air contains about 0.02 ppm of CO. The smoke from one pack of cigarettes, if distributed uniformly throughout an average sized house, could result in a CO concentration of up to 14 ppm.

An average healthy person at sea level is just barely affected by prolonged exposure to concentrations of 9 ppm, but the presence of other pollutants aggravates the situation, and respiratory and cardiac problems pose an increased risk. Chronic exposure to high concentrations of CO (30 to 100 ppm), such as in a poorly vented garage, can lead to long-term deterioration of the cardiovascular system." (1983)[3] - 01:09, 24 August 2007 (UTC)

[edit] Air quality data

It would be great if there were one integrated website people could go to for current or historic carbon monoxide measurement data for any particular locations. This is the best I've been able to find so far:

- 23:24, 28 August 2007 (UTC)

Here is a map for New England, and real 1979-2006 annual data:

For Massachusetts, here is a map of the monitoring stations:

And here are the Annual Air Quality Reports:

- 23:34, 28 August 2007 (UTC)

Access to US EPA annual database:

- 21:55, 29 August 2007 (UTC)

[edit] Heating appliance design, installation, operation and maintenance requirements

Another item that may be worth writing in to this article is government requirements concerning the design, installation, operation and maintenance of heating appliances that burn fossil fuels.

For example, unflued propane-burning portable heaters that were built since the 1980s would bave an "oxygen-depletion" sensor device which shuts the heater off if there is little oxygen burning in the room. This may also be true for recently-built kerosene heaters. Similarly, there are mandatory flueing and room ventilation requirements in most jurisdictions for installation of gas-fired appliances, especially room heaters. Similarly, people are encouraged to have their gas appliances serviced at regular intervals so that they have proper fuel-air burning ratios and ventilation requirements.

SimonMackay (talk) 15:39, 15 May 2009 (UTC)

[edit] GA

Page looks fairly good. A bit of work and it should be GA.Doc James (talk · contribs · email) 02:35, 19 December 2009 (UTC)

A few things though:
  1. A bit about how it is "the great mimicker" PMID: 16567227
  2. How the season affect its occur.
Doc James (talk · contribs · email) 02:38, 19 December 2009 (UTC)

[edit] GA Review

This review is transcluded from Talk:Carbon monoxide poisoning/GA1. The edit link for this section can be used to add comments to the review.

Reviewer: Pyrotec (talk) 09:39, 12 January 2010 (UTC)

Starting review. Pyrotec (talk) 09:39, 12 January 2010 (UTC)

[edit] Initial comments

This looks to be a strong candidate for WP:GAN, nevertheless I will carry out a full review before making my decision. Pyrotec (talk) 10:11, 12 January 2010 (UTC)

At this point I'm just going to concentrate on a few minor points.

  • Perhaps we are splitting hairs here, but the statement "In the United States, the OSHA limits long-term workplace exposure levels to less than 50 ppm" is not true. The OSHA 8 hour time weighted average limit is 50 ppm, and that is clearly stated in ref 8; peak values can be higher, 100 and 200 ppm, depending on the application, are given in ref 8. In Europe, we have a 8-hour TWA limit of 30 ppm (it was 50 ppm). (Note: I will come back to this I want to check some data first).
  • I did a copyedit on the article. Pyrotec (talk) 22:50, 13 January 2010 (UTC)
  • I'm not very keen on the statement: "Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide (CO)". Its rather vague, but at present I have not come up with a better solution. Pyrotec (talk) 22:50, 13 January 2010 (UTC)
  • That a good point, that sentence is not the best, I also have not come up with a better solution, will think about it. Mr Bungle | talk 08:39, 14 January 2010 (UTC)

[edit] Overall summary

GA review – see WP:WIAGA for criteria

A comprehensive, well-referenced article.

  1. Is it reasonably well written?
    A. Prose quality: Pass
    B. MoS compliance: Pass
  2. Is it factually accurate and verifiable?
    A. References to sources: Pass
    Well referenced.
    B. Citation of reliable sources where necessary: Pass
    Well referenced.
    C. No original research: Pass
  3. Is it broad in its coverage?
    A. Major aspects: Pass
    B. Focused: Pass
  4. Is it neutral?
    Fair representation without bias: Pass
  5. Is it stable?
    No edit wars, etc: Pass
  6. Does it contain images to illustrate the topic?
    A. Images are copyright tagged, and non-free images have fair use rationales: Pass
    B. Images are provided where possible and appropriate, with suitable captions: Pass
  7. Overall:
    Pass or Fail: Pass

Congratulations on the quality of the article. I'm awarding it GA-status. Pyrotec (talk) 19:51, 14 January 2010 (UTC)

[edit] Saturation

Carbon monoxide shifts the oxygen-dissociation curve to the left.

I'm having some trouble understanding this image. If I get it right, it says: The higher the Oxigen pressure is (horizontal axis) the higher the oxigen concentration in blood (vertical axis), with a non-linear correspondence. But why would carbon monoxide shift this toward the left now? I would expect that the oxigen pressure must be higher than normal for the blood to still bind some oxigen, which means the courve shifts to the right. --PaterMcFly talk contribs 14:44, 4 February 2010 (UTC)

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