Talk:Polychlorinated dibenzodioxins

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

POV alert[edit]

POV alert: this article is mainly about effects and laws in the US. Compare the french article, which is just as guilty (but talks about mainly france). Some cross-pollination is required! -- Tarquin 20:25 26 Jul 2003 (UTC)

The article states that dioxin "cannot travel long distances." This statement may have been meant to indicate something about the tendency for bioaccumulation, but as worded, the statement is just wrong. Nothing prevents these compounds from being put on a plane and being flown across the globe, for instance.

Incineration[edit]

This section was purely political. I've rewritten it to accurately reflect the tremendous reductions in dioxin emissions from U.S. municipal waste combustors over the past ten years, as demonstrated by the EPA.

Dioxins and Olestra[edit]

Supposedly, consumption of olestra can help decrease dioxin levels in the body; however, I do not know if this has been completely confirmed.

Comment: Apparently, the one way to lower one's body burden of dioxin is to lose fat in which the dioxin bio-accumulates.

If Olestra is a fat substitute, and if, as charged, a side-effect of Olestra is diarrhea, that may be the source of claims about Olestra decreasing dioxin levels. For that matter, dieting or a long walk, run, or bike ride would reduce dioxin levels...unless you did the exersises along an exhaust spewing highway.


Wrong....Olestra works because it is a fat. Dioxin is lipophilic. Walking etc would have no affect on dioxin levels.

Actually, excercise or any other mobilization of fat reserves (such as breast feeding) will serve to temporarily increase an individual's circulating dioxin level (as well as any other lipophilic compound) as the fat is moved to the blood stream. Might be a mechanism to increase circulating dioxin concentrations to toxic levels. Jed 06:13, 4 January 2007 (UTC)

Two Austrian women poisoned by Dioxin where put on a diet of fat-free Pringles, doctors hypothesized that the indigestible Olestra fat would mop up fat soluble TCDD, but they stopped eating Pringles after a few weeks, proving that eating Pringles for a month is more unpleasant that Chloracne. But a guy in Australia ate Pringles for 2 years and his dioxin levels dropped dramatically. --Diamonddavej (talk) 03:06, 13 December 2008 (UTC)

Dioxins in Spolana[edit]

I added a note about dioxins in the Spolana chemical plant. I have written that parts of the factory are contaminated since 60's. This was changed to "were contaminated in 60's". I want to be sure that this mean the same: certain parts of the factory are still contaminated even after 40 years. Is it clear? Miraceti 11:39, 12 Dec 2004 (UTC)

I have found MOS:TENSE to be very interesting. "were contaminated in 60's" is an event, so past tense. That is the contaminating event. So, they mean different things, but both are correct at the same time. Does that help? Gah4 (talk) 01:49, 28 May 2016 (UTC)

Please, do not use Dioxin Wikipedia page for political claims[edit]

Please, misterious story about Mr. Yuschenko poisoning is not a good example for the Dioxin page. There is no consensus about this case, and it have very strong political background. I saw a lot of refutations of this Dioxin poisoning version on Web. Sena 22:57 12 Dec 2004

The evidence in favour of dioxin poisoning in that case is now overwhelming. -- FirstPrinciples 03:13, Dec 13, 2004 (UTC)
Not really and even if it is NPOV says that we should not go beyond reporting what the doctors said.Geni 02:24, 14 Dec 2004 (UTC)
There is consensus from independent toxicologists including John Henry; lab tests in Vienna have showed 1000 times the normal dioxin levels in his blood; and the severe chloracne is undeniable. There is little doubt that Yushchenko was somehow poisoned. However, the circumstances surrounding the poisoning (e.g. was it deliberate?) are still unclear. -- FirstPrinciples 03:52, Dec 14, 2004 (UTC)
FWIW, NPR is carrying the story as "[He] was poisoned", quoting his physicians by name, as of 13 Dec 04. Baylink 04:18, 14 Dec 2004 (UTC)
The blood which was analyzed by "independent" toxicologists was not taken in official way. Mr. Yushchenko poisoning version is not proved officialy, as it should be done to be accepted as a proof in court. AFAIK all necessary procedures (like biopsy) are not done till now! I think current version is not balanced and makes somebody think that poisoning was somehow proved. --Sena 10:07, 11 November 2005 (UTC)

Whether the blood taken was analysed by independent toxicologists or not, the fact remains that chloracne is the one human clinical effect universally linked to dioxin exposure. Although there is some environmental exposure to dioxins wherever you are in the world, 10μg is the lowest level which is thought to produce chloracne and this is really not possible purely from environmental levels. People found with these levels in their body have generally have had very high exposure to dioxins (like an industrial accident), something Mr. Yushchenko would probably not have been exposed to. Unfortunately all this probably points to deliberate exposure.

Removed sentence[edit]

There is no 'safe level'; exposure to any dose can lead to cancer. This is ridiculous, it implies that a single molecule of dioxin may cause cancer, which is very unlikely and entirely unproven. See hormesis. -- FirstPrinciples 03:20, Dec 13, 2004 (UTC)

The hormesis article itself states this. It is well known that a single mutation event, whatever its cause (single molecule of carcinogen, single ionised particle) can lead to cancer. It's just highly unlikely, with the chances increasing linearly with dose.

I've re-read the hormesis article and it says no such thing. It merely describes the deficient 'linear' model. It is a mistake to assume that the dose response curve is infinitely linear; we are able to cope with a small amount of dioxin via cytochrome p450 and DNA repair mechanisms. -- FirstPrinciples 01:18, Dec 14, 2004 (UTC)

However it's not really relevant to point this out in the dioxin article, so I'm not restoring it. Dan100 23:30, Dec 13, 2004 (UTC)

Please don't delete relevant and accurate information from the article. (e.g. the hormesis link.) -- FirstPrinciples 01:13, Dec 14, 2004 (UTC)

Actually, even a single molecule can cause cancer. It is not very probable but it may happen.Miraceti 22:45, 14 Dec 2004 (UTC)

Can you supply scientific evidence for this claim, rather than just making an unsupported assertion?-- FirstPrinciples 23:03, Dec 14, 2004 (UTC)
Can you supply scientific evidence for the opposite claim?
I don't know how many molecules are needed in order to corrupt RNA and DNA processing in the cell in such a way that the cell will become a cancer cell. But I am afraid, in theoretical case, the single one is more than enough. Prove, that you need at least 2 (or n) molecules. However, this is a quite stupid discussion. I would rather write "the lowest harmless amount of dioxine in a body is very low" or something similar. Miraceti 22:11, 15 Dec 2004 (UTC)
It's simply a matter of logic and common sense. To interpolate that one molecule causes cancer, we would have to possess a technique that could deliver a single molecule of substance to a study subject. We would also have to possess a technique to ensure they had no other molecules of the same type in their body. Also, the study sample would have to be an order of magnitude larger than the population of the earth. You are free to speculate, extrapolate and "theorise" all you want, but you can not say any definitive claim has been made; nor can you say that such an event is even remotely likely.
Cancer is a highly multi-factorial disease. It occurs as a combination of genetic predisposition, immune system malfunction, DNA repair failure leading to multiple mutations, and repeated exposure to a significant and varied range of chemicals and radiation. To say that a single molecule of dioxin can cause cancer on its own with no other intervening factors simply denies our current understanding of oncology and biochemistry. (OK... it may happen; but its also true that a man from Mars may land on my lawn tomorrow. That doesn't mean we should attach any credence to either claim, and certainly we should not state them as facts, except with very explicit disclaimers.)
The EPA itself has set an absolute safe limit of 20 parts per billion. Below this the risk is irrelevant. If I eat nothing but fatty, relatively dioxin-rich food for the rest of my life, I will still recieve 10,000 times less than the minimum to feel any adverse affect. In fact, the average daily burden of dioxin is 2 parts per quadrillion which is 100,000 times less than the EPA danger limit.
So, in conclusion I simply dispute the claim that there is no safe limit. Any given population can go their whole life receiving the normal daily dioxin dose and suffer no ill effects. However, I completely agree that the toxic limit is relatively low, and when the threshold is reached the effects are extremely adverse. -- FirstPrinciples 23:41, Dec 15, 2004 (UTC)

I agree with FirstPrinciples that while one molecule MAY cause cancer, it is extremely unlikely. Also one thing to consider about any ultra-small dosage of a carcinogen, is that our bodies have self-repair mechanisms for wayward DNA/protein mishaps - this happens constantly to everybody - otherwise we'd all be dead.Joeylawn 23:54, 26 December 2006 (UTC)

Experience shows (when experiments are possible) that the linear interpolation do not work for canceriogenes and mutagenes. The statistics are suspect since only shortlived small animals and plants can be experimented with in enough numbers and duration to give god data. Fact remains that epidemological statistics show that there are probably a drop to zero with low but nonzero concentrations. One example with plenty of data is radiation which seems to show that effect is lowest at radiation levels abowe normal background radiation. (One example I like is comparing cancer in Denver Colorado with Miami Florida. Miami very low due to: 1: almost no ground radiation due to chalk ground. 2: low cosmisk radiation due to deep in thick atmosphere. Denver opposite, specially ground because of high levels of uranium in ground. Smoking, drinking and other known risks about the same. Cancer levels much higher in Miami!)

The whole subject hotly debated!!!!Seniorsag (talk) 13:16, 23 December 2011 (UTC)

Well, you can get cancer with zero molecules of TCDD, so it makes sense that you can also get cancer with one. As well as I can tell, though, the connection between TCDD and cancer is not well understood. That is, any connection between amounts and cancer probabilities. Until there is, it doesn't seem useful to make such arbitrary statements about it. Gah4 (talk) 02:01, 28 May 2016 (UTC)

Body Burden?[edit]

What is "body burden"? I guess it is some kind of technical term, but is not defined in the article. Can it be either defined or replaced with non-technical language please? Quasicharacter 05:13, 28 Dec 2004 (UTC)

Body burden means the total concentration of a (toxic) substance in the body at a given time. Graufuchs 20:07, 30 Dec 2004 (UTC)

Dioxins and birth defects[edit]

This article claims that dioxins have no effect on the unborn child, and takes 2,4,5-T (a component of Agent Orange) as an example (the massive use in the Vietnam war). I read that there are MANY birth defects, probably due to the byproducts of the herbicide, which is TCDD. I refer to the Wikipedia page for Agent Orange and two websites about people still having to cope with the effects: http://vietnam-dioxine.org http://vava.portal.vinacomm.com.vn

Neither of those sites are in English so they're probably not going to be of much help. -- FP 17:03, Apr 21, 2005 (UTC)
They are in English as soon as you click the appropriate links...

Hi, I'm not an expert, but in NZ we had some alleged (but highly likely) cases of many birth defects as a result of dioxin poisoning. The govt sprayed gorse using 2,4,5-T containing dioxin and soon after a number of cases of birth defects started popping up, including spina bifida and acephalism (children born without brains). We had 8 quite localised cases in a month; 8 times the national yearly average for these types of birth defects. There was even one street that had 3 cases of acephalism. This is very strong inductive evidence; although it is not scientific evidence.--124.197.33.229 06:52, 23 October 2006 (UTC)

There is a very thourough report published by the National Academies Press on the effects of Agent Orange on US Veterans that includes a huge amount of data. I've not digested it but here it is: http://www.nap.edu/books/0309086167/html/ Jed 06:13, 4 January 2007 (UTC)

Sources of Dioxin[edit]

When this article menstions "Residential wood burning" it implies that burning wood creates dioxins when in fact it is the burning of trash and treated wood products in fireplaces that creates dioxins.

In actuallity Dioxins can be found in all residue from burning, even a simple non-polluted tree limb. There have been tests conducted on many pottery fragments and earthenware fragments dating back to the era of the fertile crescent that have shown the presence of Dioxins (albeit trace amounts due to half-lifes). Dioxins are one of the key chemical classes focused upon in courses covering toxic substances in the environment, and are some of the oldest poisonous compounds known (even though they were not known as to what they were until modern science). Das Nerd 02:11, 4 July 2006 (UTC)

Dioxins can be formed in the low temperature combustion (burning) of organic matter along with chlorine. Thus, in particular, burning plastic trash bags containing polyvinylchloride will produce significant amounts of dioxin. It turns out that even burning trees that have been soaked in salt water (non-organic form of chlorine) can produce measureable amounts of dioxin (Environmental Science and Technology, 2005 I think). So, it does appear to have "natural" (ie non-anthropogenic) sources. However, naturally produced concentrations are likely to be vanishingly small. Dioxin does not have a half-life except as regards to biological alteration (eg bacterial). Jed 06:13, 4 January 2007 (UTC)

Plastic trash bags are typically made of some form of polyethylene, not polyvinyl chloride. Polyethylene does not have chlorine in its chemical structure. H Padleckas 20:37, 25 October 2007 (UTC)

Dioxin Debunk[edit]

Definitely POV, but I wanted to link to this. I genuinely don't know if it's accurate, but I came to Wiki for more information on its claims, and this article neither debunks nor affirms it:

http://www.junkscience.com/foxnews/fn081800.htm

Dioxin's effect on biological processes[edit]

Could someone who knows add more technical information on the effect of dioxin on biological processes? Exactly why is it toxic in a certain dosage? Thanks. Anonymous 23:14, 27 Apr 2006

Well, a discussion of how dioxin affects biological processes cannot occur without introduction of the Aryl hydrocarbon Receptor (AhR). What makes dioxin the paradigm in toxicology is that dioxin (2,3,7,8 tetrachlorodibenzo-p-dioxin) is thought to mediate most if not all of its effects through one target in the cell: AhR, a nuclear receptor. "Nuclear" refers to the fact that AhR can move out of the cytoplasm and into the nucleus of the cell to turn on certain genes, most notably the cytochrome P450s.

AhR is a very fascinating protein, and toxicologists can use dioxin to study how the AhR works in living systems. To date, every species of fish and animal studied has some form of the AhR. So it stands to reason that because AhR is so widely conserved across species, that AhR must be extremely important. Indeed, AhR has been shown to participate in the normal development of the major blood vessels in the livers of mice. Other roles for AhR in development and in other natural processes are still be investigated.

So the short answer to your first question (what is the effect of dioxin on biological processes) is that dioxin activates the AhR - dioxin binds to AhR and AhR is then able to move into the nucleus to interact with genes in the nucleus. Thus, Activation of AhR by dioxin turns on certain genes. Many of these "certain genes" encode proteins which are involved in xenobiotic metabolism (the cytochrome P450s). In essence, xenobiotic metabolism is how cells rid themselves of foreign compounds.

The short answer to your second question (why is it toxic in a certain dose range) is that higher doses of dioxin means more molecules of AhR will be activated and this can severly disrupt a cell's normal function by inappropriately turning on genes. Another explanation is that excessive activation of AhR disturbs the normal distribution of ARNT, a protein that partners with the AhR. This imbalance in ARNT can be detrimental to the cell because ARNT interacts with several other proteins which affect gene expression in the cell. Adipocytes 02:49, 12 November 2006 (UTC)

To add to this: it is believed, although still a matter of signficant scientific debate, that some of the principal routes of dioxin toxicity are via various cytochrome p450 (CYP) enzymes. Mouse gene knockout studies have confirmed that AhR is required for dioxin toxicity, but there is conflicting evidence for mice and zebrafish on the specific roles of varous CYP enzymes. One hypothesis is that attempted oxidative metabolism of the dioxin goes awry due to the chlorines sticking into the CYP enzymes incorrectly, resulting in the release of reactive oxygen that in high enough fluxes causes protein, lipid, and DNA oxidation.Jed 06:13, 4 January 2007 (UTC)

More clarification, please[edit]

I am completely ignorant on this subject, so could someone who knows please expand the article to answer these questions? First, do dioxins only occur naturally in the environment or are they also manufactured? If they are manufactured, what are they used for? The article as it stands today only seems to address the health effects on people, nothing more. Thanks! --Wspencer11 (talk to me...) 13:39, 20 October 2006 (UTC)

Dioxins are not naturally found in the environment, they are a result of unintentional man-made chlorination processes. 2,3,7,8 TCDD has no uses, but Dioxane does.Joeylawn 06:03, 21 December 2006 (UTC)

See above - dioxins can be the result of low temperature burning of plastics, household trash (containing plastics) and even just seawater-soaked logs. Thus, while significant dioxin contamination is the result of human activities, very very low levels of dioxin may have existed as long as there were salty seas and combustable organic matter (ie high enough atmospheric oxygen levels - maybe 550 million years?) Jed 06:13, 4 January 2007 (UTC)

Good point, Jed, about possible natural dioxin production. Dioxin seems to be easily formed when burning organic material with chlorinated substances. Joeylawn 22:22, 7 January 2007 (UTC)

Chemical structure[edit]

In the section "Chemical structure" there is this sentence which confuses me:

"Chlorine atoms are attached to the basic structure at any of 8 different places on the molecule, numbered from 1 to 10."


As I said, this confuses me. The numbers seem to not add up. But, hey, I'm no chemist.

- Misha

216.254.12.114 20:09, 27 December 2006 (UTC)

Hi Misha.
This is a confusing sentence. I'll reword it. The numbering of dioxins follows this pattern:
The skeletal formula of dibenzo-p-dioxin, with its numbering scheme annotated
Ben 22:56, 27 December 2006 (UTC)
Oh, thank you, Ben.
This is now understandable. The only thing I don't know now is what the white spheres in the graph at the top represent. I'm guessing this is one of those times when it's assumed one understands how to fill in the blanks...
-Misha
216.254.12.114 19:46, 31 December 2006 (UTC)

Each white circle is a letter O, representing the position of an oxygen atom.

Or do you mean the white spheres in the image below?

Dioxin-3D-vdW.png

Those are hydrogen atoms.

Ben 19:53, 31 December 2006 (UTC)

Congeners[edit]

The statement that there are 75 cogeners is not referenced. My own count suggests there should be 40. ...

I would like to know where the number 75 comes from. When I googled it, all I found were copies of the wikipedia page.

This is similar to the question voiced above:

"Chlorine atoms are attached to the basic structure at any of 8 different places on the molecule, numbered from 1 to 10."

err... you will not find anyone mentioning a 2,3,5,7,8 - PCDD. Nomad sotnos (talk) 14:59, 13 May 2009 (UTC)

The French version says:

On a identifié 210 types de composés apparentés à la dioxine (appelés « congénères »), dont 17 seulement sont considérés comme ayant une toxicité importante, la 2,3,7,8-TCDD étant la plus toxique[1].

I propose that the number 210 is also incorrect. Unfortunately, the dioxin-cogener page attempts to consider many many different structures. Nomad sotnos (talk) 15:07, 13 May 2009 (UTC)

There are 75 congeners of PCDD and 135 congeners of PCDF (210 in total). --Leyo 16:01, 13 May 2009 (UTC)

Yes, that would explain the number 210. Do you ahve a reference for these numbers, or an argument or something? I can imagine that I'm wrong, but it does me little good to imagine it... I should see it, eh? Nomad sotnos (talk) 15:47, 14 May 2009 (UTC)

See here or here. --Leyo 06:51, 15 May 2009 (UTC)

Thanks, I see it now.Nomad sotnos (talk) 13:50, 15 May 2009 (UTC)

Here are a couple of references for numbers of congeners: Poland A, Knutson JC. 1982. 2,3,7,8-tetrachlorodibenzo-p-dioxin and related halogenated aromatic hydrocarbons: examination of the mechanism of toxicity. Annual Review of Pharmacology & Toxicology 22:517-554. Safe S. 1990. Polychlorinated biphenyls (PCBs), dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and related compounds: environmental and mechanistic considerations which support the development of toxic equivalency factors (TEFs). Crit Rev Toxicol 21(1):51-88. 15:07, 13 May 2009 (UTC)

Why only animal sources of fat?[edit]

Many, many vegetables contain fat, wouldn't dioxins accumulate in them? This smacks of vegan propaganda to me.--Rotten 15:53, 11 January 2007 (UTC)

Dioxin, like other fat soluble pollutants, tend to bioaccumulate and biomagnify - that is, they stay in fat and are passed up the food chain as animals eat other animals, with total concentrations increasing up the food chain. Thus, while the ultimate origin of the dioxin in a food chain is with the 'vegetables' (since dietary dioxin usually comes from fish, this mean marine plants), intake concentrations are too low to be significant to most herbivores (unless they're very very large, eat a lot of food, and live a long time). Jed 17:31, 20 January 2007 (UTC)

Other dioxins[edit]

Are dioxins with fluorine, bromine, or iodine as toxic as the polychlorinated dioxins? Also, is the base compound dibenzo-p-dioxin (C12H8O2, without any halogen atoms) toxic? Polonium 15:22, 2 February 2007 (UTC)

Polybrominated dibenzo-p-dioxins (PBDD) and dibenzo-p-furans (PBDF) have been studied and found to be as toxic or more toxic than their chlorinated versions. Because of the increased use of brominated diphenyl ethers as flame retardants, environmentla PBDD and PBDF concentrations are on the increase, and thus more studies are being done. Fluorinated dioxins are probably less toxic, as they have much faster elimination kinetics (minutes versus days for half-life in mice. However, as fluorinated, and iodinated dioxins aren't present in the environment they've not been studied much. Jed 23:29, 2 February 2007 (UTC)

Reversion of the "first line for the layman"[edit]

I spent a great deal of time considering this change. Since a citation is still missing from the "cancer" line item under "health effects", the portion stating that dioxin has been shown to cause cancer was patently incorrect (at least it is, insofar as the project is concerned, until a reference is added). Having removed that, and unable to come up with a NPOV way to state both that some people have asserted it causes cancer and that no references for that exist, I was left with

Dioxin is the popular name for a family of chemicals released from a wide array of sources.

I hope you agree with me that that communicates very little information at all, so I reverted the change wholesale. I would strongly support a good one- or two-sentence summary at the top of the article, but I cannot support this particular one. I hope I have made it clear why. Jouster  (whisper) 18:58, 21 March 2007 (UTC)

Cancer[edit]

Reading the page closely, we have two links that say cancer is NOT a result of human exposure to dioxin, and none saying that it is. Any opposition to changing "health effects" to remove cancer and reword the "cancer in lab animals" statement, using the existing two sources as refs? TBH, I'm terrible with the <ref> tag, so if someone else is reading this and feeling nice.... Jouster  (whisper) 19:02, 21 March 2007 (UTC)

I think I need to read further into some of the specific literature to find a reference. This is still a hotly debated and researched topic - does dioxin cause cancer in humans? The new update of the "Veterans and Agent Orange" NAS report may have something to say on the topic. It's due out shortly, I believe. Jed 03:44, 8 April 2007 (UTC)
Someone was nice enough to drop in a <ref>, but it was, again, for lab animals. I edited the line accordingly, for now. The real problem is, it's pretty darn hard to run a credible, controlled study on something like this in a human population without violating every medical ethics rule in existence. I guess I'll wait for the report, and go from there. Jouster  (whisper) 08:21, 9 April 2007 (UTC)

References[edit]

Article looks good. Soon I will try to standardize all references in the text. 74.69.33.164 21:48, 25 April 2007 (UTC)


I went through and fixed the formatting of all the references so they are the same. Fixed some minor grammatical errors along the way. Next I will fix up the external links section. Demantos 00:56, 26 April 2007 (UTC)


Standardized all references. If anyone adds more, please use http://diberri.dyndns.org/wikipedia/templates/?type=pmid as a tool to create standardized references. Be sure to click the add ref tag box.


Toxicity[edit]

This modification changed "Dioxins are carcinogenic in higher amounts" to "Dioxins are carcinogenic at very small concentrations". Since neither one was sourced, and one was the exact opposite of the other, I just removed the statement wholesale. Feel free to re-add with a citation. Jouster  (whisper) 20:40, 27 April 2007 (UTC)

Added Picutre[edit]

I added a better looking TCDD picture drawn with Chem3d. Demantos 17:29, 11 May 2007 (UTC)

I think it's worse. Why remove a skeletal formula. They're standard - people want skeletal formulae in articles.
Ben 23:04, 11 May 2007 (UTC)
I agree with Ben. Each chemistry article should at least have a standardized skeletal formula with consistent appearance throughout Wikipedia's chemistry articles. Guidelines for such can be found at Wikipedia:WikiProject Chemistry/Structure drawing. For additional images such as 3D pictures, etc., I think there can be some flexibility depending what is visually best to represent the compound. In this case, there is already a good 3D image too. I'd recommend returning it to the previous state. --Ed (Edgar181) 23:39, 11 May 2007 (UTC)

Intro statement wrong[edit]

As currently stated "Dioxin is the common name for the family of halogenated organic compounds, the most common consisting of polychlorinated dibenzofurans (PCDFs) and polychlorinated dibenzodioxins (PCDDs)." Dioxin is the common name for...polychlorinated dibenzodioxins, not furans. This needs to be clarified. Likewise, why is there now a picture of a furan on the dioxin page. That needs to be removed as well. I also think the space filling model needs to be removed from the intro section since that is for a specific compound. Demantos 18:56, 29 May 2007 (UTC)

Additionally, all the furan statements should be removed from the opening paragraphs. Furans should have their own page. Demantos 19:09, 29 May 2007 (UTC)

I'll blithely assume you know what the hell you're talking about and heartily endorse this cleanup! Jouster  (whisper) 19:26, 29 May 2007 (UTC)
He does. Furans should have their own page, even though the toxicity, decontamination, etc are essentially the same.Jed 14:27, 4 June 2007 (UTC)

Cleaned it up a little. This should make more sense. I will try to find the missing citations later today. Demantos 14:18, 30 May 2007 (UTC)


External Links[edit]

Removed external links that were cited in the article. Demantos 15:18, 4 June 2007 (UTC)

Rename[edit]

I wonder, whether this article [entitled "Dioxin" as of Oct. 16, 2007] should be renamed to Polychlorinated dibenzodioxin, and a disambiguation page be created under its current [as of Oct. 16, 2007] name Dioxin, with the following contents:

The name Dioxin can describe several diferent chemical substances:

What do you think?--77.234.80.83 13:37, 16 October 2007 (UTC)

Maybe, but I'm not sure that we need a disambiguation page when only one of the possible substances has an existing article. --Itub 09:26, 17 October 2007 (UTC)


As there is no particular enthusiasm for a disambiguation page I have edited Description, and Chemical structure to include 1,4-Dioxin. Pages will be created for this and for Dibenzodioxin, which is currently redirected to Dioxin without any information of its properties on that page. The redirection will have to be removed. LouisBB 03:56, 25 October 2007 (UTC)
Maybe change the article name to Polyhalogenated dibenzodioxin with Polychlorinated dibenzodioxin and Polybrominated dibenzodioxin as REDIRECTS going to this article. H Padleckas 21:13, 25 October 2007 (UTC)
I do not currently see anything in this article about polybrominated dibenzodioxins, and I doubt they are discussed anywhere else in Wikipedia. Therefore, I think we need not bother making a Polyhalogenated dibenzodioxin article or a Polybrominated dibenzodioxin REDIRECT. Moving this article to Polychlorinated dibenzodioxin would be good enough. H Padleckas 06:57, 26 October 2007 (UTC)
Both LouisBB and I (H Padleckas) have been working on the introductory section of this article to inform the Wikipedia-reading public that dioxins originally and most correctly still refer to the two compounds with the following structures:
Dioxin isomers
and that most if not all "popular" mentions of dioxins are simplifications that should more correctly say polychlorinated dibenzodioxins or something similar. My recommendation is as follows: (1) Move this current article to Polychlorinated dibenzodioxins with appropriate simplification of the introductory section. (2) Recreate the "Dioxin" article with the current introductory section and a link to the Polychlorinated dibenzodioxins article. If nobody does this or objects, I might just do this myself in a few days. H Padleckas 07:18, 26 October 2007 (UTC)
I support your proposal, good idea.
Ben 15:11, 26 October 2007 (UTC)
Happy to agree LouisBB 15:17, 26 October 2007 (UTC)
I started working offline on the above-proposed Polychlorinated dibenzodioxins intro section. H Padleckas 21:46, 26 October 2007 (UTC)
I just made the move I proposed based on the concurrence of User:Benjah-bmm27 and User:LouisBB. Also as I proposed, I re-created a short Dioxin article from the previous intro section of the former unmoved "Dioxin" article. The Talk page has been moved too, and this last Section on this Talk page relevant to the re-creation of the Dioxin article included on the latest Talk:Dioxin page. H Padleckas 01:31, 27 October 2007 (UTC)

Since the December 08 Irish pork contamination incident...[edit]

This comment was misplaced at Talk:Dioxin (chemical) (orginally [Talk:Dioxin] before page move). I have copied it here Power.corrupts (talk) 09:13, 12 December 2008 (UTC)

I've had a look at various sources of information. There is information at the UK's HPA web site here; and at the Food Standards Agency of Ireland website.

It seems to me (as a public health/health protection consultant, but not one with great knowledge specifically about dioxins) that:

  • Dioxin, above certain levels is toxic. As you drop below these levels the toxicity drops, and at low levels it is probably harmless (or, more technically, if it does any harm, it's such a small amount of harm that it's next to impossible to detect or measure it).
  • Dioxins occur naturally as well as industrially.
  • There is a certain level of dioxin in food.
  • Your body can clear dioxin, but only slowly.
  • As long as the amount of dioxin you consume, over a period of time, is less than the amount your body can clear during that period, it is unlikely to be harmful.
  • If you consume more dioxin than your body can clear, and continue to do so, the level of dioxin will gradually build up in your body (at least until you stop consuming dioxin at a greater rate than you can clear it). If you continue to do this for long enough, dioxin levels could start to reach the levels at which it becomes significantly toxic.

For this reason, "safe" levels in food are very low indeed - otherwise people who consume a lot of a contaminated product could start to build up dioxin. But, as long as you don't continue to eat it over a long period of time, it is not dangerous to consume food with dioxin levels that exceed these safety levels by a considerable margin.

I'm not 100% certain that all of the facts above are correct, but I think they're about right. Thinking it through did raise some questions about the toxicodynamics (is that a word? - pharmacodynamics doesn't seem quite right when discussing a toxin) of dioxins. HPA guidance says it has a half-life of years (I don't have it in front of me, something like 4-7 years IIRC). Is it cleared by 1st order kinetics - at a rate proportionate to the concentration of dioxin in the body, as the statement about half life implies? Or is it more like zero-order kinetics, as is the case with alcohol (cleared at a constant rate, regardless of the blood alcohol concentration). Or does it approximate more to first-order dynamics at higher concentrations, and more to zero-order at very low concentrations? --peter_english (talk) 09:50, 8 December 2008 (UTC)

With a controversial and complicated subject its best to stick to consensus reports, and provide a few quality papers that show differing points of view in order to illustrate areas of disagreement & a lack of knowledge. Dioxins remind me of the controversy over Radiation - Linear No Threshold, threshold and hormesis (Vitamin-R). Well anyway, I see Zambon et al. (2007) are claiming that incinerators producing 4.2 fg/m3 Dioxin increase cancer rate, this is ~12,500 times lower than the dioxin levels in tobacco smoke (Muto & Takazawa 1989). Sounds a little suspicious. It illustrates why an article should to stick to consensus reports, as people can select any old paper from any old journal supporting whatever point they like to promote. --Diamonddavej (talk) 02:53, 13 December 2008 (UTC)

New page - List of dioxins[edit]

The many types dioxins are quite confusing. I have created the page List of dioxins a a first attempt to provide an overview, also of the toxicity equivalents. Comments please? Power.corrupts (talk) 15:38, 12 December 2008 (UTC)

Natural Sources of Dioxins[edit]

Two claims are made in this article-

1.) Dioxins are created whenever organic compounds are burnt at low temperatures in the presence of chlorine or chlorine compounds;

2.) Dioxins are persistent in soil.

If both of these are true, we would expect parts of the world where wildfires are common (and have been historically) to have extremely high concentrations of dioxins in the soil, since chlorine salts are present naturally in plant material. Is it true that such parts of the world have high concentrations of dioxins in their soil, and does it cause problems for the flora and fauna living there? —Preceding unsigned comment added by Dom.uk.1 (talkcontribs) 19:59, 17 July 2009 (UTC)

Italian incident[edit]

I'm not sure I buy this paragraph from the article:

"In 2007 in Italy thousands of tonnes of foul-smelling refuse are piled up in Naples and its surrounding villages, defacing entire neighbourhoods. Polychlorinated dibenzodioxins are found in animals and humans over lethal dose[63].Sources of Polychlorinated dibenzodioxins was identified in refuse and pvc combustion and industrial refuse disposal in uncontrolled industrial waste disposal. In numbers animals and humans was found lethal dose. "

First sentance, so far so good. Second sentance, not so good. It is completely false. After reading the link in [63], all I can deduce is that higher than acceptable levels were found in animal by-products, but not in the animals themselves or in humans. The third sentance isn't sourced, and judging by it's grammatical construction, seems to be fabricated from thin air. The article even goes on to mention that there's been no scientific evidence to link the two events. The fourth sentance sounds equally made-up. Heck, what it's suggesting isn't even possible- that lethal (ie, enough to kill you) doses were found in animals and humans (when nothing died or was even tested). I'll leave it in for a while in case someone honestly meant to add this, but had a really loose grip of the English language (and better sources). Lime in the Coconut 19:50, 8 October 2009 (UTC)

Joined up thinking[edit]

I'm looking over all the articles relating to dioxin, and it's a bit of a mess at the moment. This article for instance is entitled polychlorinated dibenzodioxins(PCDDs) yet contains information relating to "dioxin" contamination incidents where often the contribution to the overall level of dioxin toxicity from PCDDs is very low, relative to the toxic contribution from furans or PCBs, even more so in terms of absolute concentration of congeners, mostly relating to the Irish incident, and the Belgian incident here, but many other occasions.

I think it's wrong to include the broad discussion of "dioxin" as a toxic class of chemicals including PCDDs, PCDFs and PCBs under such a specific and in some cases inappropriate heading.

I would recommend moving this sort of information to the article dioxin and dioxin-like compounds and linking from there to this article for specific chemical and physical properties etc, as with other chemistry articles.

Arthurbagwaste (talk) 15:37, 8 September 2010 (UTC)

There is an article called Dioxins and dioxin-like compounds. You might be interested in this discussion. --Leyo 16:41, 21 October 2010 (UTC)
I agree entirely with your approach, and also that the chemical monomer 1,2-dioxin is of much less importance to readers than the toxic TCDD, TCDF and PCBs. IMO wikipedia is currently NEXT TO USELESS as a reference source for the study of the toxicity of dioxin-like compounds. Arthurbagwaste (talk) 13:13, 2 November 2010 (UTC)
This is unfortunate, because my only interest in dioxin-like compounds is their toxicity. For example, my mother constantly implores me to remove every shred of plastic from food before I microwave it, lest I expose myself to dire risks of poisoning. I regard this in the same class of seriousness as getting cancer from overhead power lines.
At one point, I had hoped that Wikipedia could be a reference for readers looking for information on toxicity of our food supply, commonly used insecticides, secondhand smoke and so on. Not that WP could settle controversies, but that it could summarize both sides and point readers to sources. Then we could make up our own minds. --Uncle Ed (talk) 18:23, 2 November 2010 (UTC)
As far as PCDDs and PCDFs go, their only relevance is as toxins, they have no other use and are produced only as the unintended side-products of combustion and other processes. Incidentally it is unlikely that you would ingest any dioxin-like compounds by microwaving plastics, the compounds released in that process would be more likely to be phthalates and bisphenol A for example FYI.

Arthurbagwaste (talk) 14:03, 3 November 2010 (UTC)

Clone[edit]

http://wikidraft.org/wiki/Polychlorinated_dibenzodioxins looks like a not correct licensed copy. --Itu (talk) 03:30, 9 January 2011 (UTC)

Cleanup: redundance on dioxins[edit]

There are now several articles on dioxins, mechanisms are mostly under 2,3,7,8-tetrachlorodibenzodioxin, general features of the group as well as toxic equivalence factors under dioxins and dioxin-like compounds, and there is a short article on polychlorinated dibenzofurans. It would be easier to the readers to concentrate the specific material under 2,3,7,8-tetrachlorodibenzodioxin, and material relevant to all compounds of the group under dioxins and dioxin-like compounds. There could be a short description of polychlorinated dibenzodioxins, similar to that of polychlorinated dibenzofurans.Viinamakelainen (talk) 19:29, 23 January 2011 (UTC)

See also two threads above and here. BTW: In de.wikipedia, the relevant article is on PCDD and PCDF together. --Leyo 20:37, 23 January 2011 (UTC)

Several problems in this article on PCDDs

  • It is not clear which data are specific for PCDDs and which apply for all dioxin-like compounds
  • Both in sources and in effects, major and trivial sources and effects are not clearly indicated
  • There is a misunderstanding of the tolerable intakes of breast-fed children. Tolerable daily intake 1-4 pg/kg/day is set such that in a future mother the body burden of dioxins will not increase to a level that would be harmful to the child either during pregnancy or during breast-feeding. In other words, TDI is not set for adults for their own sake but for the child (see WHO Consultation and Assessment, Food Additives and Contaminants 17 (2000) 223-240).
  • As correctly stated, the main source of dioxins is food. There exists no good evidence that inhalation near incinerators or other point sources would be important. The case-control study refered (Zamben et al 2007) on soft-tissue sarcoma is dubious, because dioxins were not measured. Exposure was only based on the assumption that distance from industrial plants correlates with exposure. Food is not usually local, and therefore this assumption is very weak and the conclusions shaky. There are studies actually measuring dioxins, and within the range of present dioxin concentrations there were less sarcomas when the concentrations were higher (Tuomisto et al. Int J Cancer 108 (2004) 893-900). As also indicated by animal studies, cancer may be a high-dose risk. This was also concluded by the WHO Consultation group concluding that developmental risks are more important, and cancer is taken care of adequately, if TDI is based on developmental risks.
  • The chapter "Health effects in humans" fails to tell the reader which health effects might be plausible at present low intake levels or moderately increased levels, and which are only based on severe accidents or poisonings or decades of high occupational exposures leading to hundredfold body burdens as compared with the present very low levels in populations. As stated above, developmental effects may be the only risk to be worried about.
  • Health effects in animals is better in the article on 2,3,7,8-TCDD. Most animal data concerns TCDD anyway, there is little on other PCDDs.
  • The recent German dioxin episode seems to be dioxin and not PCB episode contrary to the Belgian catastrophe in 1999. Compared with the Belgian case the concentrations in Germany seem to have been very modest, two to fivefold in only a few eggs of hundreds measured, and up to twofold in meat, again in just individual samples of hundreds measured (http://ec.europa.eu/food/food/chemicalsafety/contaminants/dioxin_germany_information_note_en.pdf). Because environmental samples are much cleaner now than before the Belgian case, these concentrations would have been "normal" in 1990s. This means that it is a question of discipline and law enforcement, i.e. rules that exist must be obeyed, but it is not a health problem. —Preceding unsigned comment added by 193.167.195.60 (talk) 17:00, 3 February 2011 (UTC)

Something should be done

The more I read this article, the more obvious is its patchy character. It contains material that really concerns TCDD and should be in the article 2,3,7,8-tetrachlorodibenzodioxin. Further it contains material that is common to all dioxins and dioxin-like compounds, and should be there. Scientifically this chapter is not very coherent, some points are well documented, some are at public media level. Probably some material should be moved to the above-mentioned articles, and only stuff relevant to PCDDs specifically should be here (compare Polychlorinated dibenzofurans. Viinamakelainen (talk) 15:19, 21 August 2011 (UTC)

Spolana 2,4,5-T sales to the US[edit]

The article mentions "Spolana stopped manufacture of 2,4,5-T (most of which was supplied to the US military in Vietnam)." While I don't doubt the manufacture of 2,4,5-T at Spolana and it's subsequent contamination, I find the claim that the US was purchasing 2,4,5,-T from a Soviet block country in the 1960's to use against the Soviet-supported North Vietnamese very suspect. The reference (which seems to be only a blog entry anyway) does mention Vietnam, but I am unable to read the entire reference as it is in Czech. Can anyone provide any insight into this claim? 24.121.33.200 (talk) 03:58, 7 November 2012 (UTC)

"1,4-dioxin" is wrong!! The proper name is 1,4-dioxane.[edit]

"1,4-dioxin" (actually, 1,4-dioxane) should not be linked to this page. It is a completely different chemical!

Deana Crumbling, M.S. USEPA crumbling.deana@epa.gov — Preceding unsigned comment added by 134.67.29.5 (talk) 13:13, 12 January 2014 (UTC)

The chemical nomenclature of these compounds is being used properly in this article. Polychlorinated dibenzodioxins are derivatives of 1,4-dioxin, not 1,4-dioxane. Dioxanes do not have the double bonds that dioxin and polychlorinated dibenzodioxin derivatives have. -- Ed (Edgar181) 13:20, 12 January 2014 (UTC)

Agent Orange[edit]

I've edited this section a little. All of the information was duplicated in Agent Orange, and the section did not make it clear that the actual herbicides are not dioxins themselves, and the concern was dioxin contamination as a result of the manufacture process. -- Will-h (talk) 12:02, 23 November 2014 (UTC)

Relative toxicity[edit]

The article mentions toxicity as a contaminant of 2,4,5-T, but not the fact that 2,4,5-T is also toxic. Seems to me, that would also be important. Gah4 (talk) 02:05, 28 May 2016 (UTC)

External links modified[edit]

Hello fellow Wikipedians,

I have just modified one external link on Polychlorinated dibenzodioxins. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

As of February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{sourcecheck}} (last update: 15 July 2018).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 21:23, 12 January 2018 (UTC)

External links modified (January 2018)[edit]

Hello fellow Wikipedians,

I have just modified 2 external links on Polychlorinated dibenzodioxins. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

As of February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{sourcecheck}} (last update: 15 July 2018).

  • If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
  • If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 10:05, 22 January 2018 (UTC)