Talk:Paraquat

Legality

• paraquat is it illegal? 12:28, 29 October 2005 82.38.113.127
• In the United States, paraquat is classified as a Restricted Use Pesticide, which means that only appropriately licensed individuals are allowed to purchase or apply it -- but it's not what you'd call illegal. ---Belgrano 07:03, 15 December 2005 (UTC)
• Removed a section that seemed to be from a company selling Paraquat. Added a linke to the CDC's information sheet about paraquat insted. Problems? 23:45, 3 January 2006 131.230.28.41
• I'd like to bring attention to the "Caracteristics" section of this article which appears quite biased to my eye. this sounds like the type of thing you'd expect from a brochure meant to promote the product. I'm not implying that any of the information is false, just that the tone might be misleading. Can anyone more knowlegeable than I please rework this section ? 65.93.193.205
• Possible issue: The article lists 2004 as the year Paraquat was allowed in the EU. This (AP) article about the now decided EU court case says 2003: http://www.pr-inside.com/eu-court-bans-toxic-weedkiller-paraquat-r169487.htm

Paraquat pot?

As paraquat is very quick acting, rapidly destroying the green tissues of plants exposed to it, it would seem unlikely that much of a crop sprayed with the chemical would ever have been used. Booshank 16:10, 18 October 2006 (UTC)

The tissues are destroyed in the sense of being killed, but they remain otherwise intact. Assuming the plant is mature enough that an adequate concentration of pyschoactive compounds has formed, it could still be harvested and used.

--Belgrano 14:37, 27 February 2007 (UTC)

Operation Paraquat

• The two articles Paraquat and Operation Paraquat (viz. the Falklands War) need some disambiguation. --Wfaxon 22:52, 29 October 2006 (UTC)
• Done. Anthony Appleyard 07:17, 30 October 2006 (UTC)

Diquat redirection

• Sorry if this is not the correct talk-page to post this on but I just searched for diquat and got redirected here. I find that a bit bothersome since they are two completely different molecules and even though they have approximately the same mechanisms (inducing oxidative stress) diquat is primarily nephrotioxic while paraquat does a lot of its damage to the lungs... Winterbay 13:53, 16 November 2006 (UTC)

mode of action?

i have read that paraquat only reacts on the green parts of plants and not roots and woody stems. the article mentions a superoxide radical that can attack unsaturated membrane lipids.

• are there only saturated membrane lipids in roots and stems?
• is there any other reason for this specificity?
• what happens when the unsaturated lipids are "attacked" by the superoxide radical?

I can't say anything about the first two questions (sicne I'm not a biologist of any kind) but the last one I can. What you get is this reaction scheme:

Radical + LH (Lipid) -> L^*, L-radical + O₂ -> LOO^*, LOO^* + LH -> LOOH + L^* (a new one that can continue the radical cycle...)

The * indicates a radical. This leads to the distruction of the cell membrane integrity and cell death (usually by necrosis). |Winterbay 20:00, 20 november 2006 (CET)

Roots and stems are susceptible to damage by oxygen radicals, but the radicals and other secondary compounds produced by paraquat destroy vascular tissue so rapidly that those compounds have little chance to translocate out of the foliage.

--Belgrano 15:56, 7 February 2007 (UTC)

mode of action?

please, TELL US MORE ABOUT THE MODE OF ACTION!! there are several articles about this, i guess the biochemistry of the mode of action it is at least as important as the "wonderful story of paraquat pot" !!!!!!!!!!

Cultural references

Rolling Stone magazine recently reported that the line, "You human paraquat!" was one of the only deviations from the script in the Coen Brothers' 1998 film The Big Lebowski. Jeff Bridges, who played The Dude in the movie described to the interviewer how the Coen Brothers normally stick completely to the script in their films, but the Human Paraquat line made it into the final cut. —Preceding unsigned comment added by 75.160.102.57 (talk) 22:38, 5 September 2008 (UTC)

paraquat pot and bpy toxicity.

I have reverted the assertion that new research shows that paraquat in pot is dangerous because this seems to be synthesis/original research. I have only read the abstract of the newly added (and now removed) source, but it seemed to be about that toxicity of bipyridines in general, and not about the hazards arising from smoking paraquat laced marijuana. If someone has access to the full text, and can confirm that it specifically addresses the issue, then by all means put it back in. But the fact the anon editor who added this info doesn't seem to know the difference between 2,2'- and 4,4'-dipyridyl (bipyridine)[1] doesn't give me a lot of confidence that his conclusions about the hazards of paraquat pot are better than the EPA's. Yilloslime (t) 23:38, 4 October 2008 (UTC)

Its a highly contentious herbicide as its still used in anti-narcotics campaigns throughout the world. A cursory search provided several competing views which should at least be represented in the article. In fact even the EPA's own website! —Preceding unsigned comment added by 76.215.158.193 (talk) 20:18, 15 October 2008 (UTC)

Modifying first paragraph.

First paragraph currently says, in effect:

Paraquat is realign the sensor dish and redirect the phase arrays through Geordies visor. Paraquat is used as a Forward nacelle antimatter transfer herbicide. It is extremely poisonous to humans if swallowed. Other members of this class include neutron density reversers, photonic translators, neutron carriers, photonic reversers, and ISDN polarisers. All of these are easily reduced to the liberal teflon, which generates hyperoxide conservative that reacts with supersaturated membrane gastropods.

Basically, it's unreadable to normal humans. First paragraph is meant to be an introduction to the subject for lay persons, and most of the stuff in the intro paragraph has no place there.

Creating a "chemical properties" section and hiving off the technobabble there. DewiMorgan (talk) 19:06, 26 November 2008 (UTC)

Looks like my edits were reverted without comment, which is poor editing form. However, tech-speak remains inappropriate for the intro paragraph, per guidelines. http://en.wikipedia.org/wiki/Wikipedia:LEAD - in particular, read the sections "Provide an accessible overview" and "First sentence" - the techspeak is far from accessible, and the chemistry is far from the most notable aspect of the substance. I'm not saying my edits are in any way perfect, but they are a start in the right direction, and give those interested in chemistry their own section to expand on that aspect of the topic. DewiMorgan (talk) 22:34, 2 February 2009 (UTC)

Thanks for dropping a note at my talk. It's been two months... Anyway, this is why I reverted your changes:

Per the Chemicals style guide (this compound IS a chemical, no matter how you slant it...), the introduction should define and classify the compound. [2] That the identity of the compound is assumed. Your original edit was to replace the original classification and remove the chemical name, inserting somewhat dramatic text in place: "... capable of rapidly killing green plant tissue on contact..."

Looking back, I might have edited, rather than reverted your edits had the replacement text been less sensationalist.

At the Chemicals wikiproject, we want to avoid dumbing down articles, while attempting to maintain accessibility to non-chemists. We can expand on what it does, etc. in the lede as well, but I must insist on following the Chemicals style guide in having the chemical name, and the classification of the compound in the first few sentences. Let's try to draft the first section below: --Rifleman 82 (talk) 05:06, 3 February 2009 (UTC)

I've re-read the article, and it seems that the statement which offended me was lifted straight out of the body of the article. Giving the issue some thought, I'm sorry I was so quick to revert. However, I'm still not happy about the lede of the article, and having the chemistry section for a chemical buried toward the end. I've prepared my first draft, please feel free to edit. --Rifleman 82 (talk) 05:22, 3 February 2009 (UTC)

Sorry to be slow to look back at this. I really like your edits, and strongly agree they are better than my edit (which was, as you spotted, just a shifting of information about to take the heavy weighting of chemistry out of the first paragraph). Hurrah for a well written middle ground! I note that "a common trade name" has been changed to "the trade name", though: I thought that Parquat was a trademark of what about all the other names in the US under which it is sold ("Gramoxone Max" in the US, etc), and of course all other countries? I haven't changed it because I suspect that I am misinterpreting the term "trade name" here: is it, perhaps, a US term that means something more than "Trade Mark"? DewiMorgan (talk) 16:40, 8 February 2009 (UTC)

It's good we have found consensus. Can't help about the trade name though. Perhaps someone else. --Rifleman 82 (talk) 19:14, 8 February 2009 (UTC)

I think paraquat is the common name and gramoxone is a trademarked product name.Yilloslime (t) 21:15, 8 February 2009 (UTC)

Draft

Paraquat is the trade name for N,N'-dimethyl-4,4'-bipyridinium dichloride, a viologen. This compound is one of the most widely used herbicides in the world. Paraquat is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings when swallowed.

Comment

The lede should end here. Discussion about the mechanism of action should have its own section

Other herbicides of the viologen family (di-quaternary ammonium salt derivative of 4,4'-bipyridine) include diquat, cyperquat, diethamquat, difenzoquat, and morfamquat. All of these are easily reduced to the radical ion, which generates superoxide radical that reacts with unsaturated membrane lipids.

I just changed the lede slightly to:

Paraquat is the trade name for N,N'-dimethyl-4,4'-bipyridinium dichloride, one of the most widely used herbicides in the world. Paraquat, a viologen, is quick-acting and non-selective, killing green plant tissue on contact. It is also toxic to human beings when swallowed.

Having the first sentence say paraquat is a viologen rather than an herbicide seemed to misplace emphasis. Certainly it is both, but the fact it is an herbicide is far more notable than the fact it is a viologen. Yilloslime (t) 21:10, 8 February 2009 (UTC)

I'm replacing "when swallowed" with "and animals". According to the toxicity section, it's also toxic in inhalation, and toxic on contact. If the story below is to be believed, it's also toxic when applied to wounds. If the paraquat story is to be believed, it may be toxic when smoked. Basically: it's toxic, to some extent, about any way you can take it. I'd hate someone to read the lede and say "my dog only fell in the vat, he didn't drink it, and he's not human... guess he's OK then", or "I only huffed it, so I'm OK". DewiMorgan (talk) 04:38, 22 September 2010 (UTC)

Viologens

The page says:

"Paraquat is one of the trade names for the viologen N,N'-Dimethyl-4,4'-bipyridinium dichloride. Other members of this class include diquat, cyperquat, diethamquat, difenzoquat, and morfamquat. All of these are easily reduced to their radical ion, which generates superoxide radicals that react with unsaturated membrane lipids."

Is any of that relevant for the "Viologens"? Probably more relevant there than here, if so.

What does "this class" mean in that context? Viologens? Things with trade names? Things with "dichloride" in the name? Needs clarifying on this point.

Does reacting with unsaturated membrane lipids explain the high toxicity of Paraquat? If so, and if this attribute is shared in common with other Viologens, then there should definitely be a section on toxicity on the "Viologens" page, and the first paragraph should contain a statement like: "Viologens are very toxic to humans if swallowed." DewiMorgan (talk) 20:13, 26 November 2008 (UTC)

Note to Rifleman 82. Your synthesis diagram for paraquat results in the wrong product. Change the pyrimidines to pyridines by removing the 2 extra nitrogens.Danabetz (talk) 21:50, 5 February 2009 (UTC)

Thanks danabetz. Was doing both 2,2' and 4,4' and forgot to change it back. i'll go fix it. --Rifleman 82 (talk) 04:17, 6 February 2009 (UTC)

correct structural name?

The lede sentence says N,N'-dimethyl-4,4'-bipyridinium dichloride; the infobox says 1,1'-dimethyl-4,4'-bipyridinium dichloride. Which is it? —Steve Summit (talk) 12:03, 8 May 2009 (UTC)

Paraquat soked sticks used to beat MDC supporters in Zimbabwe.

BBC news's Mike Thompson recently reported that MDC supporters had been beaten with sticks soaked in Paraquat. The presence of the chemical in the resulting wounds creates horrific burns and deformities. I wonder if this qualifies as an attack with a chemical weapon?

Gtech411 (talk) 15:36, 9 June 2009 (UTC)

Frequency of use in suicides?

The Toxicity section says: "Accidental deaths and suicides from paraquat ingestion are relatively common. For example, there have been 18 deaths in Australia from paraquat poisoning since 2000."

Whether or not suicide-by-paraquat is common, this statistic doesn't support it. Australia has a suicide rate of 10.9 per 100,000 people, and a population of 22,300,000, for about 2431 suicides per year, making paraquat at about 2 per year relatively rare. Ok to remove the second sentence, or is the whole thing false? —Preceding unsigned comment added by 98.250.106.18 (talk) 01:12, 15 April 2010 (UTC)

dipyridylium dichloride

The correct chemical name is not "...dipyridinium dichloride", but "...dipyridylium dichloride". 95.104.141.73 (talk) 10:46, 30 March 2011 (UTC)

Paraquat in the news

More links to Paraquat and Parkinson's disease in the news today: abcnews & medicalxpress

Summary: 'A new study shows that people who have had a head injury and have lived or worked near areas where the pesticide paraquat was used may be three times more likely to develop Parkinson's disease. The study is published in the November 13, 2012, print issue of Neurology, the medical journal of the American Academy of Neurology.'

Cowicide (talk) 18:31, 13 November 2012 (UTC)