100 things about DDT: Dissecting #10


This is another in an occasional series of posts dissecting the claims made by JunkScience purveyor Steven Milloy’s “100 things you should know about DDT.” What I find in this list is a lot of deception, misleading claims, and general unjustified vitriol. In this post I’m looking at Milloy’s point #10.

Milloy said:

10. Rachel Carson sounded the initial alarm against DDT, but represented the science of DDT erroneously in her 1962 book Silent Spring. Carson wrote “Dr. DeWitt’s now classic experiments [on quail and pheasants] have now established the fact that exposure to DDT, even when doing no observable harm to the birds, may seriously affect reproduction. Quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched.” DeWitt’s 1956 article (in Journal of Agriculture and Food Chemistry) actually yielded a very different conclusion. Quail were fed 200 parts per million of DDT in all of their food throughout the breeding season. DeWitt reports that 80% of their eggs hatched, compared with the “control”” birds which hatched 83.9% of their eggs. Carson also omitted mention of DeWitt’s report that “control” pheasants hatched only 57 percent of their eggs, while those that were fed high levels of DDT in all of their food for an entire year hatched more than 80% of their eggs.

Considering Carson’s careful citing of studies on all sides of the issue, and her use of sources dating back 30 years and more, it would be difficult for her to have “represented the science of DDT erroneously.” Carson got the science right. Milloy doesn’t even get the quote of Carson right, however, deleting her main point, and editing it to set up a straw man argument which misleads unwary readers.

Carson represented the science faithfully. Milloy simply dissembles in his accusation that she got it wrong.

In fact, Carson offered more than 50 pages of citations to studies, virtually everything available on DDT and the other chemicals she wrote about, up to the time of publication. Carson had started working on the issue in 1948, and worked almost solely on the work that became Silent Spring between 1959 and the book’s publication. None of the studies she cited has been retracted. Most of the studies were determined to be accurate in follow-up studies.

I discuss this at some length, below the fold.

There are other powerful corroborations to the accuracy of Rachel Carson’s claims in Silent Spring.

For example, because the chemical and pesticide industry mounted a strong and expensive campaign to impugn the work of Ms. Carson, President Kennedy appointed a blue-ribbon panel of scientists to evaluate her work. The President’s Science Advisory Committee (PSAC) reported in 1963 that Ms. Carson’s science was solid. They recommended that the government act immediately to try to reduce the damage being wrought by DDT and other chemicals used unwisely.

Also, the U.S. Environmental Protection Agency was created in 1969, with jurisdiction over pesticides. After EPA was sued for failing to act against DDT and other synthetic pesticides, the agency conducted dozens of studies on the effects of pesticides in the wild. On the basis of those studies, in 1972 EPA issued an order suspending the registration of DDT for broadcast use, citing toxic effects of the chemical that multiplied over the long life of the chemical in the wild. Deletory effects were cited on beneficial insects, beneficial birds, beneficial fish and beneficial mammals.

Extensive hearings in an EPA administrative law proceeding in 1972 produced a lengthy hearing record dominated by submissions from the pesticide manufacturing industry. EPA’s administrative law judge ruled that DDT was, under law, legal to use, despite evidence of extensive environmental damage. Judge Edwin Sweeney determined that he did not have legal authority to rule otherwise. His ruling was appealed to EPA Administrator William Ruckelshaus, who overturned Sweeney’s ruling on the law, and instead pointed to the record Sweeney had accumulated that showed DDT damages wildlife and posed health risks to humans whose risk was then not established. Ruckelshaus ruled that EPA did in fact have the legal authority to suspend registration of DDT as an insecticide. Of course, Ruckelshaus’s decision was immediately challenged by pesticide manufacturers. The courts ruled EPA was correct.

So Carson’s work was corroborated by high-power panels of scientists at the time, and over the next ten years official regulatory actions further corroborated her conclusions.

Most telling is this simple fact: When DDT use stopped, the reproduction problems of the affected birds began to ease. Egg-shell thinning and other bird reproduction problems, especially among raptors, steadily decreased as the residual levels of DDT and DDT by-products decreased in the birds’ bodies. Birds which Carson suggested might be in decline due to chemical assault have sprung back since DDT has fallen out of their lives. The American symbol, the bald eagle, came off the Endangered Species list in early 2007, because its populations are now considered sustainable, and its numbers have returned to most traditional ranges in the U.S. from which they were absent in the 1960s and 1970s.

Can we reconcile Milloy’s claims with what Carson wrote? Yes, but when we do, we find it is Mr. Milloy who is playing fast and loose with the facts.

Milloy quotes Carson out of chapter 8 of Silent Spring, “And no birds sing.” Carson argued that bird populations were declining because chemicals used against against insects and for other purposes interrupt the reproduction of the birds. She noted that bird watchers recorded increasingly small populations of one-year-old birds, the fledglings that would mature to produce future generations. She noted several studies of different species of birds, in the wild and in the laboratory, which showed difficulties in getting young birds from egg to successful fledge.

Milloy carefully picks one of several studies Carson cites, and he misrepresents the study’s findings. In doing this, to an unwary reader he makes a case that Carson was being deceptive. She was not; but Milloy is, in leaving out critical details.

Remember, Carson says the birds don’t make it to maturity to breed, and so the species are in trouble.

Milloy responds by quoting Carson, but very selectively. Note that he does not seriously address Carson’s point, that birds are dying before they can mature and breed, and that several species are threatened by the phenomenon; note that instead he makes it appear as if Carson were concerned solely about hatch rates:

Carson wrote “Dr. DeWitt’s now classic experiments [on quail and pheasants] have now established the fact that exposure to DDT, even when doing no observable harm to the birds, may seriously affect reproduction. Quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched.” DeWitt’s 1956 article (in Journal of Agriculture and Food Chemistry) actually yielded a very different conclusion. Quail were fed 200 parts per million of DDT in all of their food throughout the breeding season. DeWitt reports that 80% of their eggs hatched, compared with the “control” birds which hatched 83.9% of their eggs. Carson also omitted mention of DeWitt’s report that “control” pheasants hatched only 57 percent of their eggs, while those that were fed high levels of DDT in all of their food for an entire year hatched more than 80% of their eggs.

Where Milloy stops quoting Carson, she starts to make her argument: Milloy failed to cite what Carson argued!

Carson actually wrote this (I highlight in blue the words Milloy quotes, he omits the rest, some of which I’ve noted in red):

On Mount Johnson Island [in the Susquehanna River] as well as in Florida, then, the same situation prevails — there is some occupancy of nests by adults, some production of eggs, but few or no young birds. In seeking an explanation, only one appears to fit all the facts. This is that the reproductive capacity of the birds has been so lowered by some environmental agent that there are now almost no annual additions of young to the race.

Exactly this sort of situation has been produced artificially in other birds by various experimenters, notably Dr. James DeWitt of the United State Fish and Wildlife Service [Carson’s former agency; she probably knew DeWitt]. Dr. DeWitt’s now classic experiments on the effect of a series of insecticides on quail and pheasants have established the fact that exposure to DDT or related chemicals, even when doing no observable harm to the parent birds, may seriously affect reproduction. The way the effect is exerted may vary, but the end result is always the same. For example, quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched. “Many embryos appeared to develop normally during the early stages of incubation, but died during the hatching period,” Dr. DeWitt said. Of those that did hatch, more than half died within 5 days. In other tests in which both pheasants and quail were the subjects, the adults produced no eggs whatever if they had been fed insecticide-contaminated diets throughout the year. And at the University of California, Dr. Robert Rudd and Dr. Richard Genelly reported similar findings. When pheasants received dieldrin in their diets, “egg production was markedly lowered and chick survival was poor.” According to these authors, the delayed but lethal effect on the young birds follows from storage of dieldrin in the yolk of the egg, from which it is gradually assimilated during incubation and after hatching.

This suggestion is strongly supported by recent studies by Dr. Wallace and a graduate student, Richard F. Bernard, who found high concentrations of DDT in robins on the Michigan State University campus. They found the poison in all of the testes of male robins examined, in developing egg follicles, in the ovaries of females, in completed but unlaid eggs, in the oviducts, in unhatched eggs from deserted nests, in embryos within the eggs, and in a newly hatched, dead nestling.

These important studies establish the fact that the insecticidal poison affects a generation once removed from initial contact with it. Storage of poison in the egg, in the yolk material that nourishes the developing embryo, is a virtual death warrant and explains why so many of De Witt’s birds died in the egg or a few days after hatching.

Did you catch that? Milloy claims Carson was wrong because hatch rates of the DDT-fed group were close to the hatch rates of the control group. This is called “quote mining.” Milloy omits the very next three sentences including a direct quote from Dr. DeWitt:

“But few of the eggs hatched. “Many embryos appeared to develop normally during the early stages of incubation, but died during the hatching period,” Dr. DeWitt said. Of those that did hatch, more than half died within 5 days.

That changes the point a bit, doesn’t it?

  • Carson cited at least three different studies representative of a series of studies that support her point; Milloy deals with only one. The studies Carson cited have been corroborated by dozens of others.
  • Carson argued that DDT and related chemicals harm species by preventing young from reaching breeding age. Milloy claims Carson got the hatch rates wrong, but ignores the key point, the survival rates of fledglings.
  • Carson notes that even when young birds develop fully in the egg, they often die before hatching, and that among those that do hatch, high numbers die within a week. Milloy is silent about this finding, apparently counting a dead hatchling as no problem.
  • Carson cites the damage to the next generation. Milloy notes that DDT doesn’t immediately kill the present generation, rebutting no argument Carson made in this chapter.

I find Milloy’s argument dishonest. He omits Mrs. Carson’s key arguments. He omits important parts of the material he quotes. He omits the material that refutes his claims. His argument seems directed at fogging up the point Mrs. Carson made, to confuse people about her claims.

Postscript: Carson quotes Dr. DeWitt directly. Certainly he would be a key source on whether Ms. Carson misrepresented his words or his work. Unfortunately, I cannot find any indication that he is still living. I also have tried to track down others listed in the footnotes below. I found a listing for Dr. Robert Rudd as emeritus professor in the evolution division of the massive biological studies group at the University of California at Davis. However, a woman in the department office said their notes indicate he is now deceased.

When Carson wrote, these people were very much alive. Had she misrepresented their work and their words, it is likely they would have protested, and it’s possible they would have sued. I can find no evidence of any such protest, and there is no history of any such suits. Consequently, we must assume that the researchers cited by Rachel Carson agreed with her citations. I think Carson was faithful to DeWitt’s conclusions, but you can check for yourself [UPDATE, August 2012 – unfortunately the article has been moved behind a paywall; check the first page of the article here].

In contrast, Mr. Milloy now writes after these people are dead. It’s odd, troubling and a sign of warning, that Milloy claims to be collaborating with Dr. Gordon Edwards, since Edwards died in 2004 (of a heart attack while mountain climbing). Neither Edwards nor Rudd, nor DeWitt, nor most of the other sources Milloy cites, is alive to complain that he misquotes them or miscites their work, when he does (or if he does — he may be citing some of these people correctly).

Denialists love to make wild claims about Darwin and Einstein, in other science controversies. Milloy is nothing if not in denial, and that so many of his sources are dead, in a topic where there is so much live research, should certainly make one very wary of his claims about them and their research.

_____________________________________

1. Carson, Rachel, Silent Spring 40th Anniversary Edition, Houghton Mifflin 2002; originally 1962; pp. 120-121

2. DeWitt, James B., “Effects of Chlorinated Hydrocarbon Insecticides upon Quail and Pheasants,” Jour. Agric. and Food Chem., Vol. 4 (1956), No. 10, p. 863.

3. Dewitt, James B., “Effects of Chlorinated Hydrocarbon Insecticides on Quail and Pheasants,” Jour. Agric. and Food Chem., Vol. 3 (1955), No. 8, p. 672. (see abstract here)

4. Rudd, Robert L., and Richard E. Genelly, Pesticides: Their Use and Toxicity in Relation to Wildlife, Calif. Dept. of Fish and Game, Game Bulletin No. 7 (1956), p. 57.

17 Responses to 100 things about DDT: Dissecting #10

  1. […] also supports the scientists.  President John F. Kennedy tasked the President’s Science Advisory Council to check out Carson’s …, to see whether it was accurate, and whether the government should start down the path of careful […]

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  2. […] Mattes been paying attention (was he even alive then?), he’d have noted that President John F. Kennedy tasked the President’s Science Advisory Council to check out Carson&…, to see whether it was accurate, and whether the government should start down the path of careful […]

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  3. Ed Darrell says:

    I should probably revise the findings. As it turns out, DeWitt discovered that the DDT diet killed a lot of the grain-eating birds outright. The hatch studies were done on the survivors.

    Not only is DDT more deadly than Steven Milloy dishonestly paints, it’s much more deadly than I wrote above. See this comment to Deltoid’s post:
    http://scienceblogs.com/deltoid/2007/11/did_i_mention_that_steve_millo.php#comment-632424

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  4. Ed Darrell says:

    Carson’s language might have been more precise, but she was right, and Dr. Edwards’ complaint is misleading in its formulation, and downright dishonest in his answer.

    The question Ms. Carson was pursuing was whether DDT and its relatives affected bird reproduction. She didn’t focus only on hatching, but instead used the more rigorous and accurate accounting that looks at whether the birds fledge and survive their first year. On that basis, Edwards is dead wrong.

    Yes, the hatch rates for a few of the grain-eating birds were nearly normal. However, the chicks that hatched, died. The DDT prevented them from getting out of the nest. When measuring damage to birds, dead chicks a week after hatching is more deadly than dead chicks unhatched, because they have consumed more of the parents’ time and effort in care.

    A normal hatch rate is useless if the hatched chicks don’t survive to fledge, mature, and reproduce.

    Edwards carefully picks his nit, so that each bird he cites as having a near normal hatch is a grain-eating bird, not an insectivorous or carnivorous bird. Grain eaters would be least affected by DDT.

    And the study showed that even the grain eaters suffered devastating chick deaths from DDT.

    Edwards’ claims are not honestly presented. Carson was right.

    DDT for indoor use has been legal constantly — it was allowed under the European bans, and US production of DDT for indoor use continued for years after DDT was banned for broadcast use. Those who call for “more DDT” are not calling for limited, indoor use as allowed by WHO since the 1950s, or as allowed specifically under the POPs Treaty. They are calling for broadcast spraying again — since that is the only thing that is outlawed.

    Broadcast spraying was deadly in Africa, too. It kills food fish there, and lots of other animals. Africans stopped spraying in part because DDT was killing them. Recent studies show that expanding DDT use much beyond current levels could kill as many kids as would be saved from malaria — an even trade-off that is unacceptable.

    In contrast. the Gates Foundation work has demonstrated that nets and medicines will reduce malaria damage. DDT was not found to be a significant factor in recent, successful anti-malaria efforts in several African nations.

    When do we stop trying to poison the world’s poor with DDT? DDT has proven ineffective in beating malaria, and ineffective in helping the poor in any other way. When do the DDT nuts get off the dime and start helping us beat malaria?

    See this post, also, for newest information on beating malaria — without DDT:
    https://timpanogos.wordpress.com/2008/02/04/seattle-times-special-on-fighting-malaria/

    SoSo asked:

    When do we start helping the world’s poor? When do we stop arguing about Silent Spring? For better or worse, we cannot change the past. What we can change is our choices and what we choose to do going forward.

    We start helping the world’s poor when we stop assuming they are stupid, as Steven Milloy assumes. We start helping them when we trust that they know enough not to use DDT when it doesn’t work (DDT is cheap and has never been banned in Africa, not even under the 2001 POPs Treaty). We start helping them when we pay attention to Rachel Carson’s note that we cannot poison the poor to good health, but instead need to provide workable means to fight disease — in the case of malaria, this means prophylaxis to reduce exposure to the bites (like bed nets, though better housing might be better), good medical care to quickly diagnose malaria and which species of malaria parasite, and good medical care to provide the pharmaceuticals to treat malaria in humans until it is gone. Malaria is a human disease that mosquitoes simply spread from one human to another. If we wipe it out in humans, mosquitoes are no problem at all.

    We stop arguing about Silent Spring when the anti-Carsonites, the Chronically Obsessed with Rachel Carson, stop lying about what she wrote, stop lying about the effects of her writings, and stop lying about the science of DDT.

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  5. Soso says:

    “Few of the eggs hatched”.

    Anyone who wants to check Rachel Carson’s description of the results of the DeWitt study can download the original paper as I did. What you will find is DeWitt’s findings are exactly as outlined by Dr. J. Gordon Edwards:

    “Carson gives no indication of how many might be considered as “few eggs hatching.” Perhaps she thought that her readers would never see the rather obscure journal in which DeWitt’s results were published in 1956, the Journal of Agriculture and Food Chemistry. Otherwise, she surely would not have so badly misrepresented DeWitt’s results! The dosage he fed the quail was 100 parts per million in all their food every day, which was roughly 3,000 times the daily DDT intake of humans during the years of the greatest DDT use!

    The quail did not just hatch “a few” of their eggs, as DeWitt’s data clearly reveal (Table 3). As the published data from DeWitt’s experiments show, the “controls” (those quail with no DDT) hatched 83.9 percent of their eggs, while the DDT-fed quail hatched 75 to 80 percent of theirs. I would not call an 80 percent hatch “few,” especially when the controls hatched only 83.9 percent of their eggs.”

    Just download the report and see for yourself. It is available for a nominal fee online.

    While blanket spraying of DDT, a pesticide that is highly persistent in the environment should be banned, interior spraying of DDT on the interior walls of houses to prevent malaria is recommended by the World Health Organization as safe to both humans and the environment. DDT remains the most effective method of preventing malaria ever discovered. According to the WHO, interior spraying with DDT “can reduce malaria transmission by up to 90%” For more information, you can visit the World Health Organization at:

    http://www.who.int/mediacentre/news/releases/2006/pr50/en/index.html

    Bishop Desmond Tutu created a petition urging world leaders to adopt DDT to prevent malaria which was signed by over 3,000 scientists and humanitarians. It is time that we moved on from a debate about agricultural usage all of us would agree should be banned to a discussion of its use in the prevention of malaria where it’s use is safe and effective. From the WHO website, one can gain an appreciation of this problem and the monumental misery which is associated with this disease:

    “Each year, more than 500 million people suffer from acute malaria, resulting in more than 1 million deaths. At least 86 percent of these deaths are in sub-Saharan Africa. Globally an estimated 3,000 children and infants die from malaria every day and 10,000 pregnant women die from malaria in Africa every year. Malaria disproportionately affects poor people, with almost 60 percent of malaria cases occurring among the poorest 20 percent of the world’s population.”

    When do we start helping the world’s poor? When do we stop arguing about Silent Spring? For better or worse, we cannot change the past. What we can change is our choices and what we choose to do going forward.

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  6. Joshua Buhs says:

    There is little doubt that DeWitt’s research supported Carson’s claims. A couple of more things to note in support of that: DeWitt acted as a technical editor to the _New Yorker_ when that magazine ran a digested version of _Silent Spring_ in three installments. One would think that objections might have cropped up then, but there’s no sign of that. (See Lear, _Rachel Carson_, p. 405). He also published an article titled “H-Bomb in the Pea Patch” about the effect of pesticides on wildlife, which should give some clue as to his views on the matter. (DeWitt, James B. H-Bomb in the Pea Patch. Raleigh, NC: North Carolina Wildlife Resources Commission, 1957.) (For a summary of DeWitt’s work see James B. DeWitt, et. al., “Pesticidal Residues in Animal Tissues,” Transactions of the Twenty-Fifth North American Wildlife and Natural Resources Conference (1960): 277-285.)

    I don’t have a blog or website.

    Without claiming to have read through or researched all of Milloy’s claims, I can say that I don’t take him very seriously. He’s clearly cherry picking–such as with the section on birds that increased their population during the years in which DDT was used. Of course, some birds may have. But there’s also the question of whether these particular birds were exposed to DDT, something he never attempts to argue in that section.

    Like a lot of other technologies, DDT was first greeted as a wonder and there are certainly ways that it helped–during World War II it cut down on typhus, no doubt (See Russell, War and Nature). But it also had limitations, limitations that were not known at first and then were consciously ignored by people with a vested interest in the chemical’s continued use. It seems to me obvious that its widespread use in agriculture caused a lot of harm, and provided very little gain. (see Dunlap, DDT). It probably still has a role to play in malaria control, but certainly not in blanket spraying-campaigns, which only make the problem worse by causing resistance.

    In general, there was quite a lot of worry among wildlife biologists about the effect of pesticides on wildlife, worry that was grounded in research; this was often ignored by those in the agriculture community (as well as wildlife biologists who controlled vermin.) Carson came out of this background and shared with them basic views. Rudd, as I indicated above, also shared the same views. He differed somewhat in his emphases from Carson, but otherwise greatly admired her and her work.

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  7. Ed Darrell says:

    Joshua, I’d be quite interested to hear your views in more detail. Do you think DeWitt’s work indicated no problems with DDT, as Milloy claims, or does it more closely support the general arguments of caution made by Carson?

    And, how accurate is Milloy on any of the rest of his “100 things?”

    Is DDT the most nearly miraculous chemical invention, and should we use a lot more of it in a lot more places?

    Do you have a website, or a blog?

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  8. Joshua Buhs says:

    Sorry. It was to the Amazon page of my book, The Fire Ant Wars. Here is is in long form:

    I read through the fish and wildlife papers at the National Archives, such as they are, and also spoke with one of DeWitt’s collaborators, Walter Rosene. And, I interviewed Bob Rudd before he died. My characterization above is based on that.

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  9. Ed Darrell says:

    Joshua, your link isn’t working. Will you repost, please? Thanks.

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  10. Joshua B Buhs says:

    From my research, I can say that while DeWitt did not think that Carson mis-represented him, he was somewhat uncomfortable about the forcefulness of her stance. Bob Rudd, on the other hand, was a great admirer of Rachel Carson.

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  11. Bug Girl says:

    Interestingly enough, I was just talking to someone about that MSU Robin study the other day! He actually helped collect data for it.

    It’s always neat to meet a piece of history :)

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  12. dhogaza says:

    What Milloy has done is much worse that what Dan Rather did, and close to the level of deception of Jason Blair or Janet Cooke.

    What’s Fox News going to do about it?

    Oh, c’mon, you know the answer …

    Raise his salary!

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  13. Ed Darrell says:

    Here’s the question that’s vexing me (I’d say “puzzling,” but I know the answer): How can Milloy’s claim sit there on the internet for four or five years with no one else picking up Carson’s book to see what she wrote? The 40th anniversary edition came out five years ago . . .

    So far, on every claim I’ve checked from Milloy that might be interpreted as contrary to what Carson wrote, there is a similar chasm between his claim and reality. On every one.

    This raises questions about Fox News, who should be editing his stuff for accuracy at least.

    If the Washington Post caught one of their writers fabricating like that, the Post would fire the reporter. Same for the New York Times. CBS would fire an award winning anchor even though the story was right, if the evidence presented was wrong.

    What Milloy has done is much worse that what Dan Rather did, and close to the level of deception of Jason Blair or Janet Cooke.

    What’s Fox News going to do about it?

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  14. pough says:

    Great article!

    Nitpick: The sentence “But few of the eggs hatched.” is quoted and should also be highlighted.

    Question: “Carson also omitted mention of DeWitt’s report that “control” pheasants hatched only 57 percent of their eggs, while those that were fed high levels of DDT in all of their food for an entire year hatched more than 80% of their eggs.” Is Milloy claiming that DDT improves bird health? What is he talking about here?

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  15. Deltoid says:

    Did I mention that Steve Milloy lies about everything?

    Ed Darrell has been working his way through Steve Milloy’s 100 things about DDT. See if you can spot what Milloy did in number 10. Here’s Milloy: [Rachel Carson wrote] “Quail into whose diet DDT was introduced throughout the breeding…

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  16. jre says:

    A superb post! For Milloy to cut off the Carson quote right before the sentence “But few of the eggs hatched.” is an act of spectacular hackery.
    Even in 1975, it was possible for EPA to list 179 papers (pp. 69-81) documenting the adverse impact of DDT on several bird species. Today, the body of evidence is immensely larger, yet Milloy has not seen fit to cite any of it.

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