Talk:DDT/Archive 5

A point to notice
While there is a a discussion going on whether DDT should be used or not in America, it is undeniable that It should be used in 3rd world countries like in Africa to stop the spread of Malaria. Over 1 million people a year die because of the massive populations of misquotes. No doubt that this number could be lowered dramatically. Not only is DDT a type of pesticide, it is a pest repellent, meaning that even if the bug has grown immunity to the pesticide, it will invariably avoid area's where DDT is sprayed. To use it to a maximum effect, it would be a good idea to spray it on 1 wall inside a home. That's all that is required to stop the malaria epidemic in Africa. —Preceding unsigned comment added by Delata38 (talk • contribs) 14:48, 10 August 2010 (UTC)

I like that little typo: "Over 1 million people a year die because of the massive populations of misquotes." No kidding?

DDT should not be used where it would be more damaging than helpful, nor where it would be ineffective in killing mosquitoes (DDT is wholly ineffective against misquotes, I find). The annual death toll from malaria has been under 1 million people at least since 2005 -- mostly without DDT. As a repellent, DDT is much less effective than DDT, and not so effective as bednets, since DDT use assumes every mosquito gets at least one bite before being exposed to DDT, while bednets form a prophylactic barrier against mosquito bites. A few species appear to be repelled by DDT, but that does not justify the use of a substance that is poisonous to all life, when there are more effective, less poisonous repellents.

DDT is nothing if it doesn't kill. At present, DDT is used in many locations, but generally in fighting malaria there is testing done first to be sure the local population of malaria-carrying mosquitoes are not resistant or immune to DDT. There is no sense in use of DDT where mosquitoes are not killed by it (and there is some research that suggests use of DDT as a repellent speeds the spread of malaria, since repelled mosquitoes still seek out a blood meal, posing the possibility of spreading the disease).

Beating malaria requires more than just killing mosquitoes. The bugs don't invent the disease -- they must acquire the parasites from a human host before they can spread the parasite, about two weeks later after the parasite has completed the portion of its lifecycle it must complete in the bug. Research and experience suggest it is almost impossible to kill off any species of mosquito in its natural range. DDT will leave a few, DDT-resistant mosquitoes who will breed, and then there will be a population explosion of DDT-resistant mosquitoes. For DDT to work, medical care must be improved so that, while a mosquito population has been temporarily knocked down by DDT, the human hosts of malaria can be cured of the disease. Then, when the mosquitoes come roaring back as they always do, there will be no wells of infection from which the mosquitoes can get malaria, to spread it.

If DDT alone would stop malaria, India would be malaria-free, since India today uses more DDT than all the other nations on Earth combined. Yet, malaria is a serious problem in India. Edarrell (talk) 00:24, 6 March 2011 (UTC)

Yeah, and what if the mosquito has already bitten someone, gone into the house with the DDT, died, and then the DDT has killed the person/people living there? doesn't that defeat the point of the DDT? That's all the people in the house dieing, and one who was killed by the mosquito. — Preceding unsigned comment added by McChimpMacleod (talk • contribs) 20:01, 23 March 2011 (UTC)

DDT Myths
There are a lot of mythical assertions on the page that should be deleted. For one, eagle populations and DDT had nothing to do with one another. Eagles were being hunted and were rapidly disappearing BEFORE DDT was invented. When the gov't began protecting the bird, the populations began to rebound. DDT has nothing to do with thin eggs (Pesticides Monitoring Journal 4(3):136-140). If we had a dangerous chemical out there, I'd be the first one to want to ban it, but these myths around DDT have been shot down too many times, and they deserve no place in Wikipedia. —Preceding unsigned comment added by 69.58.224.12 (talk) 17:00, 12 May 2008 (UTC)

No, some mosquitos already began to have resistance before DDT was banned and DDT was banned as an agricultural pesticide, not as a malaria controller. The assumtion that this is otherwise is probably why you extrapolate the above. Munci (talk) 06:46, 10 December 2008 (UTC)


 * Why is there no reference to the WHO declaring DDT use safe? http://www.who.int/mediacentre/news/releases/2006/pr50/en/index.html —Preceding unsigned comment added by 123.208.198.223 (talk) 14:29, 20 October 2009 (UTC)


 * Basically, b/c this isn't news. Despite the strongly worded nature of the press release you cite, it didn't really represent a significant change in WHO policy. WHO has always recommended the use of DDT to fight malaria. If you read the entire press release and read it carefully, you'll see that the change of policy being announced was to start recommending its use in endemic areas. They'd always recommended it's use in areas of sporadic transmission. This is all talked in our article on Indoor residual spraying. I don't think the DDT article needs to good into this level of detail. Yilloslime T C  17:44, 20 October 2009 (UTC)

Even though mosquito populations develop resistance to DDT, they are still repelled by it. So, spraying inside of houses for vector control continues to suppress malaria transmission regardless of mosquito resistance. Resistance happens much faster when the DDT is sprayed in the environment on marshes and swamps and in agriculture. Cadwallader (talk) 19:23, 8 May 2010 (UTC)

A REAL question
I notice the abbreviation of Anopheles in this article has been An. as in ''An. culicifacies''. This is different from the Anopheles article, but more importantly against the usual taxonomic convention where it would be A. culicifacies. Is this unusual abbreviation used in the sources, and moreover are these uses in the minority or the majority of mosquito literature? --♦♦♦Vlmastra♦♦♦ (talk) 03:29, 30 May 2008 (UTC)


 * Without going back and actually checking any sources, my recollection is that Anopheles is always abbreviated An. I suspect this is done to avoid confusion with another major mosquito genus: Aedes, which, likewise, is abbreviated Ae. and is an important vector of several diseases but not malaria. Yilloslime (t) 03:54, 30 May 2008 (UTC)


 * While the above abbreviation makes a lot of sense, I've definitely seen Anopheles abbreviated as A., e.g., A. gambiae, which google-tests much better than the alternative. Graft | talk 02:07, 10 December 2008 (UTC)

If melamine has sub article why not DDT?
Melamine has sub-articles about its presence in food. Melamine is of a far lesser notability than DDT yet editors are opposed to any split of DDT into sub-articles about notable issues. Why? -- Alan Liefting (talk) - 00:24, 1 October 2008 (UTC)
 * A Wikimedia serach on "DDT" reveals 1578 pages mentioning the string. Granted that some of them are not about the pesticide, but many of them are and, among 1578, many is a large number. I'm sorry if editors can't find the right place for their PoV on this issue, but I see no reason to multiply the problem over different articles. Physchim62 (talk) 00:44, 1 October 2008 (UTC)


 * Just because Melamine is handled one way, that doesn't mean we have to handle this topic that way, too. Or one could even turn it around, and ask, If all aspects of DDT can be handled in a single article, then why not melamine? I do think there are very good reasons for the differences in the way these two chemicals have been handled, the biggest one being that no one disputes that melamine causes serious health problems and that putting it in milk or pet food or whatever, was a horrible idea. The really interesting part of that controversy is what it says about the Chinese food production system and its global ramifications. It's almost irrelevant that the chemical involved was melamine and not cyanide, RDX, Cp*Tl or some other random dangerous chemical. OTOH, the controversies surrounding DDT have a lot to do with the chemical itself and its sometimes disputed chemical and biological properties, so it seems best, IMHO, to discuss these controversies on the same page that the relevant properties are discussed on. Also—and I haven't read every word of 2007 pet food recalls, Chinese protein export contamination, or 2008 Chinese milk scandal, so take this with a grain of salt—but I suspect that these articles are bit bloated by WP:RECENTISM, and after the dust settles and they get trimmed down, it *might* just be possible to merge them into melamine. Or maybe not—I'm not saying that that's necessarily desirable. Anyways Alan, I offered up the idea of a DDT (molecule) page as a compromise, and I'm curious to know why you didn't like that. And since you last proposed splitting, I've managed to trim article down by 7Kb, and the readable prose size down by 3kB, while (IMHO) maintaining or actually improving NPOV, and cleaning up some prose and organizing things a little better. And I'm not finished yet, and I'd love it if others helped. Yilloslime (t) 04:18, 1 October 2008 (UTC)

Intro to DDT
Today I reverted an edit which added the line "The new-found interest of the WHO in spraying DDT as a cheap solution for malaria in poor regions has been described as "toxic colonialism" ". It had been added to the very top of DDT, where it didn't seem (IMHO) like a good fit. It got me thinking, though, that it would be great to use that line somewhere near the top of DDT. Some like, "The modern day use of DDT against malaria has been called everything from [ some quote about how it's the greatest thing since sliced bread ] to "toxic colonialism." Thoughts? Any ideas for what could go in the brackets? Yilloslime (t) 04:12, 9 October 2008 (UTC)


 * Sounds good. You can get lots of "best thing since sliced bread" quotes by searching google books for ddt malaria saved million lives. --Itub (talk) 09:49, 13 October 2008 (UTC)

Latest split proposal
A split proposal tag has been added to the top of the Silent Spring and the U.S. ban sub section. Lest the lack of discussion be interpreted as a lack of opposition, I'd like to go on record as opposing the removal of this information. The editor who proposed the split hasn't yet commented on his reasoning, but based on his previous attempts to split the article, I suspect it has something to do with reducing the article size and/or giving undue weight to the U.S. experience. I've presented counter arguments before, here, here, here, most relevantly here, here, and here. I don't want to just repeat myself, but at the same time I don't expect other editors to read through all the threads I just cited, so in a nut shell, here's my thesis:
 * 1) With 40kb of readable prose, the article in not in any immediate need of splitting, according to the relevant guideline.
 * 2) Since the controversy over its use in malaria control revolves in large part around it's ecotoxicity, human health effects, and "bans" placed on its use, it makes more sense to cover all these topics in one article, rather than forcing the reader to jump back and forth between several articles.
 * 3) Rachel Carson, Silent Spring, observations of bird kills and eggshell thinning, and the US ban are all critical points in the global history of DDT. Therefore, the weight given to these topics in the current article is not too much, and removing the Silent Spring and the U.S. ban sub section would remove essential information. I don't think you can write about DDT without mentioning Silent Spring, and I don't think you can put Silent Spring in context without an overview of the environmental effects of DDT observed in the 1950s and 60s. That those observations and the book they spurred where from the U.S. and not Canada or France or whereever is immaterial, and we shouldn't deprive the reader of this information simply because it all happened to occur in the U.S. As supporting evidence, please see http://www.ajph.org/cgi/reprint/AJPH.2007.122523v1, a recently published history of DDT and malaria control, intended to put the current controversy in perspective. It's 8.5 pages, the last 1.5 are references, and the author spends about 1 page on DDT in the U.S.: ecological effects, Silent Spring, EDF, the Wisconsin ban, Ruckelshaus's ban, etc.

For these reasons, I also think that the tag on top of the History section is unwarranted. Yilloslime (t) 10:31, 26 October 2008 (UTC)

DDT ban in the US
As a little side note to the US section - the United Farm Workers with the encouragement from César Chávez championed much of the public outcry (farm workers' civil rights to have a safe place to work) in '69/'70 or so that culminated to the ban. The section makes it sound like environmentalists did it themselves. (Source: Beyond the Fields: Cesar Chavez, the UFW, and the Struggle for Justice in the 21st Century). JoeSmack Talk 19:08, 29 December 2008 (UTC)

Please a precision about a referred study
I am not a specialist of DDT, just a precision : "In contrast to studies which measured DDT or DDE late in life, a recent study ..." is this study the one noticed in the precedent paragraph (note 49) ? —Preceding unsigned comment added by I:I Orin I:I (talk • contribs) 17:16, 11 February 2009 (UTC)

Economic Arguments
I deleted the reference to the IEA publication in the Human Exposure section because it is not a scientific source that addresses toxicity studies or chemical analysis, thus not relevant for this type of citation. It focuses on economic arguments, such as reduction in number of cases of malaria correlating with DDT use.

The IEA paper declares that DDT is "cheap, safe, and easy to use" (p. 36) and "toxicity unproven" (p. 68, which is the ONLY reference to "milk" in the entire 112-page document). The publication presents no evidence for the claim "safe", other than one citation questioning breast milk toxicity. It seems that IEA may have their own POV. Presenting opposing POV is one way to achieve neutrality in WP, but this IEA document is NOT a scientific study.

However, the IEA paper has interesting information on broader economic impact, including human productivity and indirect ecological impact in terms of cutting wood for fuel in Africa. If the IEA study is going to be mentioned at all, I recommend that it be utilized in a new section called Overall Economic Impact. There is abundant discussion of toxicity claims in preceding sections, so no need for this non-scientific study to be cited in Human Exposure. Martindo (talk) 03:51, 13 May 2009 (UTC)


 * Wikepedia is not a scientific journal. You can cite any reputable published source, as long as it isn't "self-published". However, cited sources should actually make the claim they are being cited in support of.Cadwallader (talk) 16:27, 8 May 2010 (UTC)

Human Exposure
I truncated the title of this section because the first paragraph explains that it is hard to determine that DDT spraying is only done for vector control, not for "unauthorized" agricultural uses.

I added a paragraph that summarizes a study in New Guinea which found some mothers had higher levels of DDT in breast milk than allowed in commercial cow's milk. The 1992 WHO bulletin mentioned in this section also indicates gram/kg levels that are higher than the cow's milk standard.

This section could be improved by a concise explanation of the mechanism of DDT storage in lipid tissue, "excretion" via lactation (i.e., women had less DDT in milk when nursing the second or later child), and general mechanism of accumulation of DDT via the food chain (possible reason it was found in breast milk in remote villages of New Guinea where no spraying had been done). It would only take a few sentences to do this, greatly enhancing the overall picture without bloating the length of the WP entry. Martindo (talk) 06:10, 13 May 2009 (UTC)

Othmar Zeidler
I added the name of DDT's original discoverer from 1874 - Othmar Zeidler - into the article. Unofrtunately, I have little experience with wiki programming, so I don't know how to link the word to the article. Could someone provide assistance? Thanks. 76.71.30.82 (talk) 00:53, 8 June 2009 (UTC)


 * THis info is already covered in the first line of the history section, and I would argue that we don't also need it in the 3rd sentence of the article. We generally only mention the most important aspects of the subject in an article's lead, and I don't think that this fact rises to that level of importance.
 * But to answer your question: you put double brackets around a word to generate a wikilink. So Othmar Zeidler gives you Othmar Zeidler. See Cheatsheet for more editing help. Yilloslime T C  01:01, 8 June 2009 (UTC)

Since you're a more experienced editor, I'll trust your better judgement on the matter. Thank you for the assistance regarding the links, by the way. 76.71.31.212 (talk) 21:59, 9 June 2009 (UTC)

Misrepresentation of sources
The following is from the carcinogenicity section: There is good epidemiological evidence (i.e. studies in humans) that DDT causes cancer of the: Liver Pancreas Breast The first source cited for this section is this lancet paper: http://depts.washington.edu/molmed/courses/conj504/2007/session2/rogan_lancet2005. Some extracts: Although extensively studied, there is no convincing evidence that DDT or its metabolite DDE increase human cancer risk. … Previous case-control studies have suggested that a history of DDT use was associated with a raised risk of non-Hodgkin’s lymphoma, but subsequent studies using measurements of total DDT concentrations in serum did not ﬁnd such increased risk. Two other studies using the history of DDT application as the exposure measure and one using adipose DDE concentration reported a slightly raised risk associated with DDT or DDE, but the effect disappeared if data were adjusted for history of use or concentration of other pesticides. The second source cited for this section is http://www.ehponline.org/members/2009/11748/11748.pdf. Some extracts: Most human studies reviewed by IARC in 1991 did not show an association between DDT exposure and cancer risk. Some studies suggested that DDT exposure may be associated with certain cancers (lung cancer and lymphomas); however, the lack of control for exposure to other chemicals, small study size, insufficient data on confounding factors (e.g. incomplete information on tobacco use), as well as short follow-up time for long-latency cancers, limited the ability to make any conclusions at that time (IARC 1991). Research on DDT/DDE exposure and cancer continued to yield mixed results following the publication of the IARC report. The claim of “there is good epidemiological evidence” is not supported by these two sources, and these two sources would seem to argue for the opposite of this claim.--Themadhair (talk) 17:20, 28 July 2009 (UTC)


 * I noticed this discrepancy as well, but unfortunately my edits have been reverted twice now. Please don't use a source that clearly contradicts the claim be made, it discredits Wikipedia. 96.48.65.167 (talk) 14:57, 1 September 2009 (UTC)


 * Both sources appear to be reviews of evidence rather than primary studies.
 * The first (Rogan & Chen, 2005) does mention evidence that liver cancers are caused in rodents and non-human primates, and briefly discusses weaker studies that indicate liver cancer in humans. Pancreatic cancers do not appear to be discussed, although the review cites a paper on them (citation 55).  The paper does mention breast cancer and cites a number of studies that are supportive of a link, but goes on to cite other population-wide studies that do not find this.
 * The second source (Eskenazi et al., 2009) includes a section that specifically tackles all three cancers (pg. 1361). It reports some correlation between DDE and liver cancer, but with ethnographic variability.  It reports mechanistic explanations for DDT links to pancreatic cancer and discusses some evidence for these.  On breast cancer the paper seems to suggest that studies point both directions, but goes on to cite recent work that more carefully relates DDT exposure to breast cancer while considering the age at which exposure occurs.
 * IMHO, I think your (96.48.65.167) rewording of the article is not contrary to these papers. Certainly, the description of the evidence for DDT links to the cancers as "good" appears somewhat too strong given these sources (although my reading is that both studies would consider this link as likely; especially given the proposed mechanisms by which DDT could act).  Any epidemiologists out there who'd care to comment?  Cheers, --P LUMBAGO  16:42, 1 September 2009 (UTC)


 * I reinstated the descriptor "There is epidemiological evidence (i.e. studies in humans) that DDT causes cancer of the:.." before liver, pancreas, and breast. I agree that using the term "good epidemiological evidence" is perhaps a stretch since the source (Eskenazi 2009) doesn't actually use that word, but I don't think lumping liver, breast, and pancreatic cancer together with leukemia, testicular, and lymph cancer is in line with the source either. Even though they don't use the word "good", clearly Eskenazi et al is putting liver, pancreas, and breast cancers in a different, somewhat less-equivocal category that the other cancers, so what we do here should reflect that. The abstract uses the wording "may be associated with" for conditions "such as breast cancer...", so perhaps we could use that wording for this category, but I'm happy with the way it's phrased now. FWIW, when I rewrote this section I relied more heavily on Eskenazi 2009 than other reviews since it is the most recent. The IP editor wants to insert the quote from the Rogan & Chen paper, but I don't think this is appropriate as that paper is 5 years old--we have more up-to-date sources (i.e. Eskenazi 2009, which BTW Chen is a co-author on) so we should preference those. Yilloslime T C  21:58, 1 September 2009 (UTC)


 * I'd go with this. I hadn't thought about the lumping of liver, etc. with leukemia, etc. before.  Oops.  Anyway, I'd agree that Eskenazi et al. (2009) single out liver, etc. for special consideration, and that their study is both a more recent review, and one which draws in a wider range of researchers (so should be a "better" review).  I'd also add that the second quoted excerpt above is not really representative of the full paper.  The quotation is mostly talking about the IARC study of 1991 with a passing negative remark about subsequent studies.  But the paper goes on to review the evidence from later studies, and comes to quite different conclusions (albeit non-definitive ones).  Cheers, --P LUMBAGO  07:51, 2 September 2009 (UTC)

What is the RATE of these alleged DDT driven cancers?
DDT causes this, DDT causes that. H2O also causes all sorts of bad things and is linked to many more. What is the RATE of extra cancer cases due to DDT? The people who oppose the ban are claiming (rightly or wrongly, I don't know) that DDT could be used to wipe out malaria in Africa. Well, we know that actual malarial death rate is pretty high, and alongside child mortality there is also the debilitation of adults that prevents them from working and drives them deeper into poverty. So do the advocates of the cancer position claim that DDT would unleash a wave of cancer on a scale rivaling the malarial damage in Africa? Or are they just the sort of lying, manipulative type of people that the critics allege they are? 76.24.104.52 (talk) 20:57, 16 December 2009 (UTC)


 * DDT is listed by the US Government as a "suspected carcinogen" which means that is has never been clinically proven to cause cancer, but they still think it probably does. Given that DDT has had more toxicity and carcingenic studies done than any other substance, if they haven't proved it causes cancer yet, it is unlikely that they ever will be able to prove it.  If it hasn't been clinically proven to cause cancer, then know one knows the rate of cancer increase in the real world, because they can't get it to cause statistically significant rate of cancer in lab rats even when feeding it to them in high concentrations.Cadwallader (talk) 16:22, 8 May 2010 (UTC)

Early history.
The article says that DDT was first made in 1874 but that its pesticide properties were not found until 1939. There is a 65 year gap with no information at all. What was it invented for in the first place? What was its initial purpose and how was it found? Thanks.  Stepho  (talk) 02:49, 26 March 2010 (UTC)


 * The man who first created DDT was merely trying to create and document chemical compounds. He did not test them for application.  So he synthesized the chemical, documented it in his notebook and moved on to the next one on his list.  65 years later a Swiss chemist, Mueller, was attempting to find ways to control clothes moths.  He was not aware of the original discovery of DDT. He rediscovered it by creating various chemical compounds and testing them on insects. The reason there is a 65 year gap, is because no research on DDT transpired in those 65 years. Cadwallader (talk) 19:28, 8 May 2010 (UTC)

I agree this article is too focused on "health concerns" and not on any science or history. The point of wikipedia is not to necessarily refer people to other websites through citations. There should be an article on it's history and if no mechanism of action as to how it works is added most of the health concerns should be deleted seeing as how they only cite government websites that review the claims. The government websites state that most of the concerns are unfounded.Tomgazer (talk) 16:16, 10 April 2010 (UTC)

Criticisms of DDT
This whole section does not present the critisms of DDT alone. Rather it cites a sound bite of a criticism, then quickly jumps to a counter or refuting comment or evidence by DDT detractors. The proper way to present this, is to have a section that covers the criticisms of DDT, and then have a section that covers DDT protagonist and there commentary.

Virtually this whole Wikipedia entry is transparently one-sided and is a raw cheer-leader for the activist position that DDT should be banned. All evidence or commentary in favor of DDT is quickly trounced and chided by assertion of other evidences, and it is clear who the authors here side with. Not an unbiased exposition on the topic. The mode of action on insects, and/or the differences versus other insecticides, is unexplored.

It it a biased and unabashed anti-DDT exposition.Should be cleaned up to present the evidence in a much more neutral fashion.


 * I have to agree with the above sentiment. A criticism section should present a summary of the critical point of view without editorial comments, rather than having each critical sentence immediately refuted by the following sentence.  The current version of the critical section reads like a debate or a flame war on a discussion forum, rather than an encyclopedic article. The majority position promoted by media and scientific journals is clearly that DDT is a dangerous environmentally-persistent chemical compound. However, there are over 40,000 scientific papers that have been published concerning the effects of DDT, and there is a size-able body of reputable scientists who did not believe DDT to be dangerous to vertebrates or the environment.  So, the criticism section of this article should state the position of this minority, as well as a few prominent names.  The rest of the article presents the DDT is EVIL position just fine.  You don't need to refute the critics in the middle of the summary of their position. Cadwallader (talk) 16:17, 8 May 2010 (UTC)

DDT Toxicity in Cats
The current version of the article cites the oft-repeated urban legend of DDT application in Borneo killing all the cats in one village, leading to an invasion of disease-bearing rats, leading the RAF to air drop cats into the area to control the rats. While there is a grain of truth at the heart of this story (there really was a cat drop to one remote village), the cats in question were not killed by DDT in the food chain, they were killed by direct spraying kerosene solution that had either 5% DDT or dieldrin dissolved in it. For a study of the origin of this story see:

While there is some anecdotal evidence that anti-malarial spraying programs occasionally killed cats that came in direct contact with the insecticidal spray, the testimony at 1969 U.S. Congressional hearings on DDT indicated that the cats were probably killed by ingesting dieldrin an alternative to DDT that was being used by the WHO in some of the spraying programs, or the kerosene that the DDT was dissolved in. Unlike DDT, which has been shown by repeated chronic and acute laboratory studies to have very low toxicity to mammals, including cats, dieldrin is highly toxic to mammals as well as insects. For this reason dieldrin was banned in the 1970's. DDT's toxicity in cats is well studied, and the median lethal dose is well established as 300mg/kg of cat body weight. ( For comparison, the common household chemical hydrogen peroxide has an LD-50 of 50 mg/l in rats - meaning hydrogen peroxide is roughly six times more toxic than DDT in mammals.) The lethal dose for an average sized 4 kg cat would be 1200 mg of DDT (1.2 grams of pure DDT).

Because DDT is extremely insoluble in water ( < 1 mg/L @ 20C ), it was usually dissolved in a 5% solution in kerosene for indoor spraying. In order to ingest a lethal dose of DDT the cat would have to drink more than 1 liter of the kerosene solution, which is about 99% kerosene. Kerosene is lethal to humans in doses of about 2 grams/kg of body weight, with similar toxicity in mammals. So if the cat ingested about 8 grams of DDT spray (a couple of teaspoons), it would be killed by the kerosene. The most likely cause of the anecdotal cat deaths was the cats were directly sprayed and licked the spray off of their fur and died from kerosene poisoning.

My little mini-article here is undoubtedly "original research". However, citing DDT as toxic to cats is a perpetuation of an urban legend in a supposedly "encyclopedic" article. If you want to mention DDT and cats in this article, it should include a link to actual acute toxicity tests done on cats with DDT, many of which were published in the 1960's. Cadwallader (talk) 18:18, 8 May 2010 (UTC)

Edits by Cadwallader
I've reverted today's edits by Cadwallader. Here's my reasoning: Hope this makes sense. Yilloslime T C  20:20, 8 May 2010 (UTC)
 * Silent Spring and the US ban is much more NPOV than Politicization Leading to the U.S. ban. (See also WP:MOS for capitalization insection headings).
 * This sentence "The public discussion about DDT grew increasingly politicized and polemical especially after the publication of Silent Spring. Arguments for one side or the other tended to be made from ideological positions rather than from a scientific point of view." is uncited and/or WP:OR.
 * If that sentence is removed, then there's no point including the two quotes that coming after it. (Also one of them was made 13 years before Silent Spring was published, so doesn't support the argument that "public discussion about DDT grew increasingly politicized and polemical especially after the publication of Silent Spring.")
 * The catdrop drop stuff is largely WP:OR and I don't think catdrop.com is a WP:RS. The text I reverted back to only said that "[DDT] is less toxic to mammals but cats are very susceptible, and in several instances cat populations were significantly depleted in malaria control operations that used DDT, often leading to explosive growth in rodent populations," which completely inline with what the cited Am J Public Health article says, except for the part about cats being "very susceptible" so I've removed that part.
 * Changing "it is a reproductive toxicant for certain birds species" to "DDT has been linked to reproductive problems in certain birds species" really understates the degree of certainty about DDT's effects on birds. It hasn't merely been "linked", it is well established that it "is" a repro tox.
 * Finally that same sentence goes onto say that DDT "... was cited as a major reason for the slow recovery of the bald eagle, ...." which is wrong. Banning DDT is cited as major for the recovery of these species.
 * I agree with all of these except the cat stuff - I'm not sure a long discussion is needed, but it would be nice if there was greater clarity on the subject. I.e., is DDT actually toxic to cats (seems unlikely), or was some other part of the spraying responsible, or was this merely an urban legend? I can't read the APJH article, so if it clarifies, please explain here. The article right now seems to suggest higher toxicity in cats compared to other mammals, which seems a contentious claim that ought to be supported by a direct study, as Cadwallader suggests. Graft | talk 18:12, 10 May 2010 (UTC)
 * Currently the article only states that "[DDT] is less toxic to mammals but cats, though in several instances cat populations were significantly depleted in malaria control operations that used DDT, often leading to explosive growth in rodent populations." It doesn't say that DDT is directly toxic to the cats or that cats have increased sensitivity to DDT vis-a-vis other mammal. This statement is well supported by the cited Am J Pub Health article. Here's a partial excerpt of the relevant part: "One of the most controversial side effects of indoor residual spraying of DDT was the deaths of domestic cats reported in a variety of areas throughout the world. These deaths were invariably associated with an increase in rodents and the additional negative effects they caused. [goes onto cites NYT times article discussing the phenomenon] Likewise, a 1959 annual report on conditions in Sabah contained the remark, “Field rats were a greater menace than usual, partly as a result of antimalarial spraying which accidentally killed many cats.”20 Furthermore, in his text on malaria, Robert Desowitz mentioned that cats died in villages in Thailand after homes were sprayed with DDT, which also resulted in an increase in the rat population.21 ... An investigation conducted in 1965 by Karl Johnson determined that an outbreak of Bolivian hemorrhagic fever was “due to invasion of houses by rodents” as a consequence of cat deaths after the spraying of DDT.22 During the investigation, the villagers remarked that the cats “would have the shakes, get sick, linger for a few days, and die.”23 Johnson had one dead cat analyzed by a toxicologist at the Centers for Disease Control and Prevention in Atlanta... The DDT concentrations found were determined to be high enough to kill cats. A 1977 Time article also reported on cats dying from ingesting DDT on their fur.... Two anthropologists who worked in the southwest Pacific when malaria spraying occurred there also observed cat deaths... In singling out DDT, Carson stated, “[O]ne caused by the animals licking DDT off their fur; one stated that her own cat had probably died in that manner within 2 weeks of spraying, because the cat was otherwise fed pet food..." Yilloslime T C  18:44, 10 May 2010 (UTC)

As per WP:RS: "How reliable a source is, and the basis of its reliability, depends on the context. As a rule of thumb, the more people engaged in checking facts, analyzing legal issues, and scrutinizing the writing, the more reliable the publication."

Some of the revisions are fair enough. However, the American Journal of Public Health article as quoted above is entirely based on anecdotal evidence. There have never been any published studies that determined that multiple cats were killed by DDT spraying. Analyzing one dead cat, is still anecdotal, and would not qualify as a study.

The catdrop.com site in this case meets Wikipedia's criteria for a reliable source because it's very purpose is to check the facts of the story by going back to the original citations - and it doesn't take a particular position on whether or not DDT is harmful to cats - it merely documents the origin, repetition and credibility of the story. And it provides excellent citations.

The reason the Am Journal of Public Health relied on anecdotal stories is that no scientific study has ever been published that demonstrated a connection between the reported rodent problems and DDT spraying, or that DDT was the actual insecticide used in those particular instances and not dieldrin, which the WHO was using for antimalarial spraying in Borneo and other countries at the time this story was reported.

The catdrop.com site also cites two WHO officials (Brown and Wright 1969) that “DDT as applied has not caused any side effects among domestic animals (the matter of the North Borneo cats as misinterpreted in Time concerned dieldrin, not DDT)”.

Occams Razor says, if WHO officials said in writing they were using dieldrin in Borneo, and dieldrin is known to be highly toxic to mammals, which it is, then the simplest explanation is that the anecdotal cats were far more likely to have been killed by dieldrin than by DDT, which has been very well established as one of the least toxic pesticides to mammals, including cats.

So, I think the DDT->dead_cat->rodent_invasion story, though oft repeated, even in the American Journal of Public Health, still ranks as an urban legend, and doesn't belong in a Wikipedia article. It is a very interesting story from an entertainment point of view, to be sure. And it might belong in the article on dieldrin, but even then it has never been proved that dieldrin was the cause either. Cadwallader (talk) 05:19, 11 May 2010 (UTC)

I could see including the dead cat story as part of the history of the public discussion of DDT as long as it is clarified that the story has never been demonstrated to be true, and the anecdotal cat deaths were probably mis-attributed to DDT. Cadwallader (talk) 05:22, 11 May 2010 (UTC)


 * Regarding my change concerning the bald eagle. DDT was not responsible for the decline of the bald eagle.  The reason is DDT wasn't invented until 1942 and didn't come into widespread use in the USA until the 1950's.  The bald eagle population steeply declined from the 1800's to 1940 because the most states were paying a bounty for people to shoot them.  When DDT came on the scene the bald eagle was already on the verge of extinction.  So, assuming the DDT eggshell claims to be true, at best DDT inhibited the recovery of the bald eagle after the US Government made it a protected species.  DDT is persistent in the environment, and despite the fact that DDT levels in the birds have not declined much since the 1970's, happily the bald eagle population has greatly recovered.  (I saw one by the river a few weeks ago.)


 * So if the goal is accuracy in reporting here, it is fine to say that DDT was believed to be harming the reproduction of bald eagles, but to say that DDT wiped out the bald eagle population simply is not true. Cadwallader (talk) 05:33, 11 May 2010 (UTC)
 * I'm fine leaving the cat thing out--it's tangential at best, and although well sourced, I don't think it needs to be here. (Also catdrop.com appears to be self-published source, and therefore not probably reliable per WP:RS. It certainly doesn't trump an article in Am J Public Health, a peer-reviewed scientific journal. But I digress...) The bald eagle thing, though, I think you're unacceptably watering the language down. The article says that DDT was "a major reason" not the "the only reason" for their decline, and this is backed up numerous reliable sources cited throughout the article. Also, do a googlenews search on given day and you will find dozens of article saying pretty much the same thing, so this is the majority viewpoint (to say the least) and it what the article should reflect, per WP:WEIGHT. Yilloslime T C  18:17, 11 May 2010 (UTC)


 * Just because something false has been repeated many times doesn't make it true. The American Bald Eagle was on the verge of extinction in 1940, three years before DDT was invented.  Therefore, DDT could not have possibly been the cause of the decline of the American Bald Eagle because DDT did not exist. It doesn't matter how many idiots since then have blamed the decline of the bald eagle on DDT, it still isn't true. Since 1940 the American Bald Eagle has made an amazing recovery, despite high levels of DDT residing in the environment, which have continued after the ban due to DDT's long half life. The problem with Wikipedia's reliance on peer reviewed journals is that many such as the American Journal of Public Health are laughably prone to group think and sloppy writing. Peer-review is no guarantee of truth.  It depends entirely on who the peers are. Cadwallader (talk) 16:10, 24 May 2010 (UTC)


 * By the way here is a far more encyclopedic article on this subject: . It is not "peer-reviewed" and I'm not listing it as a source, but as an example of how to present a OPOV article on the decline and recovery of the American Bald Eagle.  DTT is mentioned, but not a major factor. Cadwallader (talk) 16:17, 24 May 2010 (UTC)
 * Wikipedia is not the place to right great wrongs. At any rate, this article seems entirely consistent with the baldeagleinfo.com page that you linked above. Yilloslime T C  16:25, 24 May 2010 (UTC)


 * Neither is Wikipedia the place to perpetuate great myths. Then again maybe it is. Cadwallader (talk) 16:34, 24 May 2010 (UTC)

New Outline for article. Where did it all begin? The USA
The article has a lot of good aspects, but I wish to fix a glaring omission as to why DDT came to be demonized by the environmental movement and Silent Spring... the answer is the full-bore attack in the 40s and 50s by the US government on malaria and the use of it en masse in agriculture in the US and other places.

So, here is where the article loses the focus of a true history... here are some quotes:
 * In 1945, it was made available to farmers as an agricultural insecticide, and it played a minor role in the final elimination of malaria in Europe and North America.


 * As early as the 1940s, scientists in the U.S. had begun expressing concern over possible hazards associated with DDT.

But both of these statements are not fully in line with the full story. The points I would make are many, but here are some of them.
 * 1) The US CDC went after malaria with DDT as its primary weapon. They essentially sprayed thousands of homes with DDT and sprayed it around numerous swamps and creeks and ponds. They didn't spray, for example, Malathion or DEET.
 * 2) It took 4 years.
 * 3) Malaria had been in steep decline since the 1930s (due to the use of other pesticides and the climate changes of the dust bowl and the industrialization of agriculture), but it was still present in the Southern USA.

Okay, now that was one part. Part two is this... Legend has it that malaria was driven to extinction in the USA by DDT spraying.
 * I think that this article should tackle that legend and show both sides of why this may or may not be true.
 * 1) People should know that on the one hand, DDT was the only thing shown to be cheap and effective in the 1940s which could produce the desired effect of malaria eradication.
 * 2) People should know that this is still one of the options (this fact is covered in the article already) over 50 years later.
 * 3) People should know that the case of the USA in the 1940s was ripe for ridding itself of malaria. It was already down. The article does have a quote, One CDC physician involved in the United States' DDT spraying campaign said of the effort that "we kicked a dying dog." which covers this.

The first point would be well served by the CDC's own discussion of the program. The eradication program is the source of the legend, and yet this program is not mentioned. (It is called the The National Malaria Eradication Program and its website is http://www.cdc.gov/malaria/history/eradication_us.htm )


 * Adding some of this missing info about the CDC's program will also flow better in another way. Before the UN even existed in its final form (The World Health Organization didn't exist until 1948), the US CDC was taking the lead in eradicating malaria for the first time ever. Since I and many readers would know this fact, it would make a lot more sense to present the CDC as the first org with malaria eradication and DDT programs. The WHO didn't attempt this until the USA was successful, and they modeled their DDT programs around "The National Malaria Eradication Program."
 * In summary, I like the many points made by the article as written, but it is mixed-up in its historical flow, sort of like spaghetti.
 * The article needs to discuss both the "well known" or "popular" topics of malaria eradication and "Silent Spring" issues, but as in the previous point, these would make more sense if covered in the order in which they occurred. Otherwise, we get a feel for "DDT is deadly" before we read that "prior to that, DDT was used as a prevention against deadly mosquitoes."
 * The article has a penchant to not state well-known facts, such as how it was used in agriculture and its effects on production. The "silent spring" would not have happened if it weren't for the indiscriminate, widespread uses, and those uses wouldn't have happened if it weren't for the dead bugs and happy farmers.
 * The writer of Silent Spring was from the USA and a lot of the media attention happened in the USA as things transpired. There is a gap as to why there was such an interest in the USA... but it should be obvious if the reader has been prepared by facts of USA's heavy use of DDT in agribusiness. People of that era will remember the constant spraying and the lack of sense on the part of many who used it so profusely.

''I feel that the article misses a lot of the obvious and preliminary details to make it flow. I would challenge anyone to look at the article and support this statement, "The article as it is now written flows logically and fluidly from one topic to another, with a good order laid out to guide the reader from the simple to the more advanced aspects of DDT." Otherwise, it could stand some rewriting. A lot of you old editors are not seeing how jumbled this thing is.''

This is a rough orderly outline of the train of events. Enjoy. - I like to saw logs! (talk) 06:01, 27 May 2010 (UTC)
 * 1) DDT makes bugs dead.
 * 2) DDT makes farmers giddy. (see #1 above)
 * 3) DDT makes diseases disappear; makes doctors smirk and government agencies goofy. (see #1 above)
 * 4) DDT is used in the US, as they had the money and need for making farmers/doctors happy and bugs/diseases disappear. Triumph for science on a national scale. DDT 1, Malaria 0, (or so the storyline goes).
 * 5) The WHO says let's keep doing what the USA did and copy their idea. So does Europe, Americas, Africa, etc.
 * 6) Meanwhile, some problems arise. Not all farmers and doctors happy, and not all diseases or all bugs disappear. Too much of this junk everywhere. It's like Visa.
 * 7) Silent Spring. Dead ducks. Tree huggers save whales and write books. Simultaneously.
 * 8) More problems with this and other pesticides. DDT 5, Malaria 5, Birds 0.
 * 9) Modern times, we look back and we still use this awful stuff. #2 is no longer legal. #1 is still true, but less so than 60 years ago. #3 is so controversial, that the article will be constantly vandalized for hundreds of years.


 * I'm don't think I really agree that the article is "mixed up in its historical flow like spaghetti" and would flow better in things were reordered. I think it tells the various stories that need to be told in a logical way. That's not to say that things can't be improved upon though. For one, I agree that the agricultural use of DDT is not given as much attention as it deserves. Yilloslime T C  19:21, 29 May 2010 (UTC)

Copy-edits
Reduced the word-count by about 10%. In the pro/con sections, it would be great to see more research and fewer claims/counter-claims. Reactions appreciated. Cheers! Lfstevens (talk) 20:44, 10 June 2010 (UTC)

Food source, food quantity..
Shootbamboo reverted my edit that asserted: It should not be overlooked, however, that diabetes is also caused by obesity, and obviously people who eat more are going to be exposed to higher levels of the pesticide.

Could we maybe get someone from vegan or vegetarian in here to speak about the fact that DDT is a pesticide that bioaccumulates, so people who eat lots of meat will be eating lots more DDT than vegans or vegetarians; and furthermore, that generally speaking in the United States people who are obese are generally also consumers of large amounts of meat? I don't feel like researching those facts because I'm pretty sure some hippy has already done the work for me and will probably find this request. (I'm seriously hoping nobody was actually disputing the link between diabetes and obesity..) 98.177.243.69 (talk) 00:49, 14 September 2010 (UTC)


 * This sounds like WP:OR and is not appropriate for the article unless you have a reliable source. 75.36.152.175 (talk) 17:36, 31 May 2012 (UTC)

Call for limited/controlled reintroduction of DDT for use in bed-bug infestation
I am wanting to add a new section (one or two paragraphs) to this page regarding a call for limited/controlled reintroduction of DDT for use in bed-bug infestations (in the U.S.) Granted I find reliable references, is this addition appropriate for this page??? I really don't want to take the time to write it all out and then have it deleted. —Preceding unsigned comment added by 72.193.86.185 (talk) 09:58, 17 November 2010 (UTC)

If you check the science papers and history, I think you'll discover that bed bugs showed resistance to DDT as early as 1948, and by 1960 every tested population was immune to the stuff. The great elimination of bed bugs came through use of other pesticides besides DDT, especially after 1960. There were a couple of papers published in 2009 showing that every population of bedbug is still highly resistant to DDT at a minimum, and many are strongly immune to it. Consequently, the controversy over bringing back DDT is a teapot tempest urged by those ignorant of the facts, or by those who wish to create more controversy over DDT. There are a few places you can get a quick education on the issues, including Bug Girl's blog: http://membracid.wordpress.com/2009/02/05/new-research-on-bedbug-insecticide-resistance/  (and see her post on DDT here, too:  http://membracid.wordpress.com/2010/11/23/brian-dunnings-ddt-fail/ ). Edarrell (talk) 00:43, 6 March 2011 (UTC)

Inaccuracies, perhaps misleading statements
The article states that Rachel Carson wrote in Silent Spring that DDT causes cancer. She did not write that. She expressed concerns about cancers being caused by that class of chemicals, but nowhere in the book does she say that DDT causes cancer. She was much more careful than that.

Reading the article gives one the impression that the U.S. 1972 ban on DDT led directly to the Stockholm Convention. It would be useful to note that the Stockholm Convention did not result in a ratified treaty until 2001.

The article suggests that the Endangered Species Act played a large role in the recovery of the bald eagle. While true, that is misleading for the purposes of this article. The recovery of the eagle -- and peregrine falcons, brown pelicans, and osprey -- was in nearly direct correlation to the measured decrease of DDT and DDT-breakdown products in the tissues of the mother birds. While there are dozens of studies that show DDT was the significant factor preventing the recovery of the Bald Eagle after the laws protecting the birds were strengthened in 1941, there are few studies which can be interpreted to suggest anything other than DDT thinned the eggshells. Hunting of eagles was a problem addressed by federal law in 1918 and 1941; DDT kept the species from recovering after that.

The EPA order in 1972 cancelled only registration for agricultural use, by then, mostly on cotton. Specifically, the order left manufacturing operating, for export for use of DDT against health problems (malaria, yellow fever, and other insect-borne diseases).

The article should note that WHO's malaria eradication campaign was frustrated by DDT-resistant mosquitoes discovered in Africa. WHO essentially stopped use of DDT in Africa in 1965; in 1969 WHO officially ended the campaign to eradicate malaria, switching instead to control of the diseases.

Many statements appear to have been inserted in response to other statements, some of which may not be in the article still -- and generally, it is a mess. It may not be possible to make a non-messy article on such a controversial topic, but one can hope.

References should include Sonia Shah's excellent book, The Fever, How malaria has ruled mankind for 500,000 years http://soniashah.com/books/the-fever/

On the controversy over DDT, reference should be made to Merchants of Doubt by Naomi Oreskes and Erik M. Conway, who have a chapter on the DDT controversy: http://www.bloomsburypress.com/books/catalog/merchants_of_doubt_hc_104

Edarrell (talk) 08:45, 28 February 2011 (UTC)


 * Ed: all very good observations. In fact, many of these are fixes that I myself have been meaning to make for quite some time, but haven't gotten around to. If you have the time and inspiration, I encourage you to jump right in! Yilloslime T C  16:57, 28 February 2011 (UTC)