DDT: Secret Life of a Pesticide

Is DDT a killer of birds, a savior against malaria, or a little of each?

by Brian Dunning

Filed under Environment, General Science, Health

Skeptoid #230
November 2, 2010
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Also available in Russian

Put on your respirator and hazmat suit, because today we're pointing the skeptical eye at the claims on both sides of the DDT question. DDT is an insecticide in use since the 1930's. At first, its basic use was to kill mosquitos that transmit malaria, lice that transmit typhus, and other insect disease vectors like tsetse flies, at which DDT is extremely effective. It was so successful in World War II that its discoverer was awarded the Nobel Prize in medicine in 1948. Subsequently it was used in agriculture to protect crops from a variety of pests, and once again, it's highly effective in doing so. But a few decades later, DDT became a two-sided issue, with detractors pointing to health effects on humans and animals; most notably, eggshell thinning in various bird species, and a number of potentially severe health effects in humans. In response to these concerns, DDT has now been banned for the most part in many countries. But the controversy continues. While the ban has been credited with the rebound of bird species, it has also been criticized as overzealous, with many now saying the detrimental effects were overblown and did not outweigh the many lives saved from malaria in the third world. It is in fact making a comeback, with production increasing today in India, China, and North Korea, for both agricultural and anti-malaria uses.

And so we ask the question: Is one side completely wrong and one side completely right, or do we equivocate and conclude that DDT has its place, albeit a limited one?

DDT is dichlorodiphenyltrichloroethane. It's a completely synthetic compound that does not exist in nature. It's a white, powdery, waxy substance that's hydrophobic: It doesn't dissolve in water and so does not contaminate it, but readily dissolves in solvents and oils. It's applied as a white smokey mist. DDT kills insects by chemically enhancing the electrical connections between their neurons, short-circuiting them into spasms and death. DDT's hydrophobic nature is both a blessing and a curse. It can't contaminate water sources, which is good; but it also doesn't get dissolved away by them and diluted into virtual nothingness, so it hangs around for a long time.

DDT probably never would have been banned if it were not for the 1962 publication of Silent Spring, the title of which alluded to dead birds. Author Rachel Carson was a much beloved nature writer who died only two years after the book came out. She'd been a marine biologist for the U.S. Fish & Wildlife Service (then called the Bureau of Fisheries), but was able to retire with the publication of a trilogy of books about the sea. All became bestsellers in the 1950s, with the public enamored by her poetic presentation of all things pertaining to beaches, islands, the deep sea, and the creatures living there. Following this trilogy, her writing turned toward environmental issues and became increasingly critical of industry, government, and the effect of humans on the planet. Silent Spring was serialized in The New Yorker before its publication, and it was probably the most scathing of her works, though beautifully written. It charged DDT with being a health hazard and with widespread environmental destruction, particularly to bird populations, and was unquestionably the turning point which resulted in DDT's bans in the United States and other countries. In fact, as one Environmental Protection Agency writer put it:

"Silent Spring played in the history of environmentalism roughly the same role that Uncle Tom's Cabin played in the abolitionist movement."

Rachel Carson's list of posthumous honors is a long one, showing what deep roots Silent Spring thrust not only into the environmental movement, but also into the public psyche. President Jimmy Carter awarded her the Presidential Medal of Freedom. She appeared on postage stamps in several countries. A bridge in Pittsburgh is named after her, as is a government building in Harrisburg. The number of schools, parks, nature refuges, scholarships and scholarly prizes named for Rachel Carson would fill a page.

Silent Spring's principal thesis was that DDT harms bird populations through eggshell thinning [Correction: Silent Spring did not specify the eggshell thinning mechanism; that was proposed later by other researchers - BD]. The mechanism by which DDT does this is now largely, but not completely, understood. In summary, it interferes with the delivery of calcium carbonate to the eggshell gland, and the eggs that are laid have thinner shells. Shells that are too thin can lead to the death of the embryo. This eggshell thinning is the primary environmental concern over DDT.

It's been about five decades since Silent Spring was published, and we've learned a lot in those years. One thing we've learned is that DDT is only one of many causes of eggshell thinning. Other culprits include lead and mercury toxicity, oil, phosphorus and calcium deficiency, and dehydration. Perhaps most significantly, birds in captivity in order to undergo testing are under stress, and this stress alone is enough to produce eggshell thinning. Although DDT's mechanism for eggshell thinning is plausible, many studies throughout the 1970's and 1980's failed to correlate such thinning with high levels of DDT, even extremely high levels. Other studies have confirmed Rachel Carson's findings. My own conclusion based on a review is that there probably is a correlation, but it's not a strong one; and at best it's only one of many causes. Whether DDT is used or not would probably not have a large impact on bird populations.

But despite the likelihood that it would have some impact, it's now known that the species Rachel Carson focused on (most notably bald eagles) were already in massive decline from unrelated pressures even before DDT's introduction. Habitat loss and hunting had been, by far, the greater causes of bald eagle deaths. Hunting had reduced the populations to just a few hundred nesting pairs in the mountains, and lowland eagles were already gone from habitat loss. Rachel Carson did not ignore these issues in her book, but the popular perception that banning DDT was all that was needed to magically restore bald eagle populations was naïve. In the end, it was the Bald Eagle Protection Act and the bird's 1967 placement on the endangered species list, combined with increased penalties for poaching, that ultimately led to the bald eagle's successful return to remaining habitats.

Brown pelicans are another species often cited as having been decimated by DDT use in the United States, along the Gulf coast and in California. Massive declines were indeed correlated with DDT use, but it may have been a coincidence in each case. Along the Gulf coast, hunting by angry fishermen had reduced the pelican population in Texas from 5,000 annual births to just 200 in 1941. The California populations suffered a double whammy in the years following Silent Spring's publication; first with an oil spill off Santa Barbara in 1969, and then with an outbreak of Newcastle Disease in 1971 that unfortunately required the culling of millions of brown and white pelicans [Correction: the birds that were destroyed were 12 million poultry. Only four wild birds were found to be infected, none of them pelicans - BD]. DDT certainly didn't help; but it was another case where the bird populations would have dropped sharply whether DDT was in the picture or not.

Of course, it would be completely wrong to overlook DDT's potential for causing harm simply because there are other things that cause harm too. All we can do is our best to quantify exactly what the risk really is, and then the decision to ban or not to ban becomes a cost/benefit analysis, which is no longer a science question. Everyone has the right to their own opinion on what's most important, and in the United States, we chose the birds.

Silent Spring's legacy may have been good for the birds, but not so much for human populations in the third world. DDT is one of the most effective pesticides ever discovered for fighting malaria. Although DDT remains legal for insecticide use in most areas where malaria is a major killer, the money for fighting the mosquitos often comes from donors in wealthy countries like the United States. Such wealthy donors have often had little personal exposure to the issues, and can sometimes have a skewed perspective when it comes to bald eagle eggshells in the United States versus the deaths of children in Mozambique. Writing in the Nature Medicine journal, malaria advocate Prof. Amir Attaran criticized American environmental groups for opposing the public health exceptions of DDT bans:

"Environmentalists in rich, developed countries gain nothing from DDT, and thus small risks felt at home loom larger than health benefits for the poor tropics. More than 200 environmental groups, including Greenpeace, Physicians for Social Responsibility and the World Wildlife Fund, actively condemn DDT."

As a result of these pressures, many donations now coming from wealthy nations are now contingent upon DDT not being used, which leaves the poor nations with fewer options, often too expensive and less effective, and children die. Up to three million people die of malaria each year, most of them in Africa. DDT, while it does have environmental and health concerns like all pesticides, is not known to have ever killed anyone. If we shelve our most effective tools hoping that something perfect will come along that has no potential downside, we'll wait forever, and thousands will continue dying every day. These are the cases where wealthy environmental groups appear to do their best to justify their elitist stereotype, at the expense of brown people. [Additional info: The World Health Organization's ban on DDT does include limited exemptions for malaria control in many regions, but money for its use still often depends on qualified foreign aid. In Africa, the exemption allows indoor use only, like wearing armor on half your body - BD]

Rachel Carson absolutely acknowledged DDT's importance to fighting malaria, but was quick to point out another downside: acquired resistance. After six or seven years, mosquito populations develop resistance to DDT. However, this is the case with all pesticides, it is not a reason to avoid DDT per se. Moreover, we've since learned that it is still effective against resistant mosquitos, only a little less so. Susceptibility in resistant strains goes down to 63%, as opposed to 87% in non-resistant strains.

Tip Skeptoid $2/mo $5/mo $10/mo One time

Even among resistant mosquitos, DDT is an exceptionally effective repellent. Houses treated with DDT are avoided by all mosquitos, resistant or not.

But like all synthetic chemicals, DDT has been blamed for virtually any human illness imaginable. Some say it causes cancer, diabetes, hyperthyroidism, loss of fertility, that it functions as an endocrine disruptor, and more. The World Health Organization classifies it only as "moderately hazardous", and in response to all the wildly conflicting studies of its cancer-causing effects in animal tests, the U.S. Environmental Protection Agency classifies it as a "probable carcinogen". The claims that DDT definitely causes cancer or anything else are not supported by the data, but obviously it's a risky compound that we don't want to expose anyone to if we don't have to. And so, again, we're outside of science questions, and down to risk assessment.

DDT does have its place, and its current usage is probably not too far off of what it should be. The exception is Africa where DDT's upside far outweighs the down, and my opinion is that donors should relax their restrictions against it, and leave those decisions to the experts on the front lines in Africa. For much of the rest of the world, DDT has largely been supplanted by newer and better agricultural pesticides, and there's insufficient reason to put collateral species under pressure. A scientific review nearly always produces better focused policy, and our DDT policy is definitely due for a tuneup.

Note - I've gotten a lot of criticism for including a link to the JunkScience.com web page on DDT in the References & Further Reading section below. Bizarrely, most of the criticism attributed Milloy's assertions to me, even though I clearly did not say any of it or agree with it. I try to always offer Further Reading suggestions from both sides of Skeptoid topics (you don't think I really listed Rhonda Byrnes' book The Secret because I think you can wish yourself wealthy, do you?). Steven Milloy, the author of JunkScience.com, gets lots of well-deserved criticism for cherrypicking and adhering to a conservative political agenda. I've said it before, and I'll say it again: Skeptoid is not here to tell you what to think. I want you to read and research for yourselves. You'll find that virtually every Skeptoid episode lists sources you are going to disagree with; if I've done my work well, the sources should cover the full spectrum. I will not whitewash the world and pretend certain points of view do not exist.

With that said, corrections will be made to erroneous assertions in this episode in a future Things I'm Wrong About episode, and are noted in the transcript above. The errors that have been pointed out to me so far are not, in my opinion, significant enough to alter my conclusions. I welcome any and all further corrections.

Brian Dunning

© 2010 Skeptoid Media Copyright information

References & Further Reading

Attaran, A., Roberts, D., Curtis, C., Kilama, W. "Balancing risks on the backs of the poor." Nature Medicine. 1 Jan. 2000, Number 6: 729-731.

Campbell, L. Endangered and threatened animals of Texas: Their life history and management. Austin: Texas Parks & Wildlife, Resource Protection Division, Endangered Resources Branch, 1995. 58.

Carson, R. Silent Spring. New York: Fawcett Crest, 1964.

Edwards, J., Milloy, S. "100 things you should know about DDT." JunkScience.com. Steven J. Milloy, 7 Jan. 2007. Web. 2 Nov. 2010. <http://www.junkscience.com/ddtfaq.html>

EPA. "DDT - A Brief History and Status." Pesticides: Topical & Chemical Fact Sheets. US Environmental Protection Agency, 16 Jan. 2008. Web. 9 Dec. 2010. <http://www.epa.gov/pesticides/factsheets/chemicals/ddt-brief-history-status.htm>

Gates Foundation. "Our Work in Neglected Diseases: Visceral Leishmaniasis, Guinea Worm, Rabies - Overview & Approach." Bill & Melinda Gates Foundation. Bill & Melinda Gates Foundation, 14 Jun. 2010. Web. 30 Oct. 2010. <http://www.gatesfoundation.org/topics/Pages/neglected-diseases.aspx>

Gladwell, M. "The Mosquito Killer." The New Yorker. 2 Jul. 2001, Annals of Public Health: 42.

Lambert, T. "Skeptoid Fact Check (parts 1 and 2)." Deltoid. ScienceBlogs LLC, 22 Nov. 2010. Web. 22 Nov. 2010. <http://scienceblogs.com/deltoid/2010/11/skeptoid_fact_check_part_1.php?>

Miller, H. "Utterly Repellent." Forbes.com. Forbes.com LLC, 24 Feb. 2010. Web. 29 Oct. 2010. <http://www.forbes.com/2010/02/24/bill-gates-malaria-vaccines-opinions-contributors-henry-i-miller.html>

Stokstad, E. "Can the Bald Eagle Still Soar After It Is Delisted?" Science. 22 Jun. 2007, Volume 316, Number 5832: 1689-1690.

Reference this article:
Dunning, B. "DDT: Secret Life of a Pesticide." Skeptoid Podcast. Skeptoid Media, 2 Nov 2010. Web. 13 Oct 2015. <http://skeptoid.com/episodes/4230>


I'm not convinced that stress due to captivity is a relevant factor in explaining egg shell thinning. A modest degree of scientific rigour would have included a control group when examining the effects of DDT on captive birds. While it's certainly important to be aware of, mentioning it here without specifically targeting the methodology of the studies themselves felt a little like a red herring.

quarksparrow, Guelph, ON
November 2, 2010 8:17am

Your "science" comes from Malcolm Gladwell and the JunkScience website of tobacco/oil shill and professional denialist Steven Milloy?

Max, Boston, MA
November 2, 2010 8:28am

Great article! The hyperbole on both sides of this issue has needed pruning for years.

Chris Terry, Duluth, GA
November 2, 2010 8:48am

Methink our entire generation was showered with very bad information about pesticides mixed with an anti viet-nam war, anti industrial agenda, colonial guilt, etc... A bit like GMO are bundled today with an anti-capital rhetoric.

I can remember seeing pictures of dioxin damages (Agent Orange) and then see the name "DDT" wrongfully associated to it. And I grew up believing it. It was standard granola propaganda in the 70's-80's. It was politically effective but it taught me a completely wrong version of science.

Denis Solaro, nice, France
November 2, 2010 8:55am

Well for my part I think the issue was "we like to center out one point out of many and make it a huge scary issue" while forgetting that while DDT has a role, that man, many other factores may also have been at play.

This is more a mental exercise, and quite nicely fits along with Stewarts and Colberts Sanity rally. Dont overblow a few major issues up. Lots of things are going on and we need to examine them all rationally. We ALL have a tendency to see a scary weasel word pop up in the news and then harp about how incredibly dangerous that is, and then next week beled along by the nose by the next overblown scary issue.

Misquitos and DDT yep, worthy issue but also look at the larger lesson here.

Cam, Thunder Bay
November 2, 2010 9:44am

Yeah, the very fact that you would consider Junk Science a source worthy of citing frankly is enough to treat the entire article with extreme skepticism. Junk Science is nothing more than an anti-science ideologically driven libertarian/industry front group. I prefer to get my science information from the scientific consensus, not partisan free market ideologues.

Robert E, Greensboro, NC
November 2, 2010 10:06am

Feel free to point out any flaws you find, I'll happily correct them.

I'm not sure your political disagreement with one of my sources constitutes a valid correction to anything in the episode.

Brian Dunning, Laguna Niguel, CA
November 2, 2010 10:30am

Environmentalism and medicine find common ground on subjects like this - nothing is free (cost or risk) & nothing is perfect. Ecological interventions are a risk/reward analysis, same as medical interventions.

I think there is an argument to be made in favor of DDT use to control malaria. Of course, the WHO already recommends that.

But to get there did you really need to cite JunkScience.com? A little time on SourceWatch left me a little skeptical of their motivations and methodology. A little time on the JunkScience.com front page left me extremely skeptical, especially once I got to their section on "gorebull warbling" (their words).

It works both ways - if the science is good then why do you need to cite a source like that? A source that is a 'wall of text' where every citation is of equal weight and little context is established?

JJ, Calgary, Alberta
November 2, 2010 12:11pm

I love how people are focusing on teh source, and not the information. Certainly we should be skeptical of JunkScience.com--not because its content leads us to question it, but because it exists. We should never take ANY analysis at face value. Skepticism isn't limited to those ideas you dislike, but to ALL ideas, even our own deeply held beliefs. That said, to "Poisoning the Well" is a fallacy for a reason.

Gregory, Alabama
November 2, 2010 12:21pm

I think the point Brian is trying to make is that that source should be evaluated based on what it presents.

Tokorona Shinjitsu, Puyallup, WA
November 2, 2010 12:23pm

I trust JunkScience on health and environment like I trust the Discovery Institute on evolutionary biology, or Prison Planet on history.

These denialist sources are minefields of logical fallacies, outdated studies, cherry-picked data, out-of-context quotes, and red herrings.

Is that where Brian got the idea that "perhaps most significantly" the stress of captivity alone is enough to produce eggshell thinning?
quarksparrow pointed out that this feels like a red herring, because any good scientist would control for this. But deniers love to throw red herrings to divert attention from the primary culprit.

Max, Boston, MA
November 2, 2010 1:01pm

The JunkScience guy has a blatant libertarian agenda. The SourceWatch guy has a blatant anticorporate agenda. Big whoop! They're both still researchers. I have no problem citing either if they've done the research I'm looking for.

If you must insist that this makes everything coming from either guy always right or always wrong, then you should demand to see the voting history of every scientist or researcher in order to determine the quality of their work.

What can you tell me about the politics of any of the other sources listed? You better find out!

Brian Dunning, Laguna Niguel, CA
November 2, 2010 1:11pm

"Is that where Brian got the idea that "perhaps most significantly" the stress of captivity alone is enough to produce eggshell thinning?
quarksparrow pointed out that this feels like a red herring, because any good scientist would control for this."

Not necessarily. You need to know that the variable exists before you can test for it--if you don't (either because it's not your area of interest or because it's unknown) you miss it. I remember laughing aloud when one of my professors speculated on the origin of certain chemicals in a lake--he was a biologist and missed the fact that a HUGE geode filled with those chemicals was directly under the area he was researching.

Besides, this is mere speculation on your part. I've been to JunkScience.com. The author cites his sources. You can check up on this yourself. While I'm certainly skeptical of what he posts (I'm skeptical of ALL analyses), the lack of critique of the data involved can only be attributed to lethargy in these cases. Sure, he may skip the ones he disagrees with--but he presents the studies he discusses.

Gregory, Alabama
November 2, 2010 1:29pm

I enjoyed your article and agree that the real issues tend to be more risk assessment and policy. If DDT caused the extinction of the bald eagle, but saved millions of lives---what to do?

That's policy not science.

All ideas should be treated with skepticism. I think there might even be devoted to conveying that message, isn't there? I'd like to thank those who tell me what sources not to read, I guess they think others are unable to make those judgments and need help.

Are there any significant issues between farm workers and DDT?

Roger, Alameda, CA
November 2, 2010 1:29pm


It's not the Junkman's politics that's the problem. It's that he's a NOTORIOUS DENIALIST AND SHILL. For example, instead of offering Libertarian solutions to Anthropogenic Global Warming, he denies the problem.


Simply keeping both the exposed birds and the non-exposed controls in a similar environment would control for environmental stress.

JunkScience does say that stress is associated with eggshell thinning, and cites a study in poultry, so I'm not sure if Brian extrapolated from that or checked another source.
Brian's claim that "Other culprits include lead and mercury toxicity, oil, phosphorus and calcium deficiency, and dehydration" appears to be right out of JunkScience.

Deniers are notorious for muddying the waters and shifting the blame. It's not DDT that killed the birds, it's stress. It's not CO2 emissions that cause Global Warming, it's sun activity. It's not Nazis who killed the Jews, it's famine. When you've seen enough of this, it becomes obvious.

Max, Boston, MA
November 2, 2010 3:00pm

Brian, PubMed indicates that eggshell thinning is significantly correlated with DDE levels (a DDT metabolite) in many bird species.

This appears to be the majority/consensus view. Of course, it isn't the only thing of concern (PCB contamination anyone?) and I get that this article is about properly weighing a complex issue. I will readily accept that DDT has too 'toxic' a reputation.

That said, it appears that the shell thinning hypothesis is well accepted in the literature.

JJ, Calgary, Alberta
November 2, 2010 3:28pm

It might be best, when you're going to give weight to an argument that's counter to a strong scientific conclusion, to google the source along with a credible science source. A google of "Steven Milloy & scienceblogs.com" for example, would have yielded enough links to give pause to Milloy's credibility on the issue.

Milloy was the guest on an early episode of Skeptics Guide to the Universe, and during the interview, you can tell that Steven Novella gradually became aware that Milloy seemed to be predisposed to an ideology over objective science.

CW, Ann Arbor, MI
November 2, 2010 4:23pm

Brian, apart from the political weirdness of Junk Science and Steven Milloy, and the taint of the tobacco lobby money there, have you checked out any of the citations offered?

Gordon Edwards was a well-respected entomologist, but he appeared to go around the bend on Rachel Carson and DDT. His critiques of DDT research and Carson could not get published in science journals -- so it ended up being published by Lyndon Larouche. That alone makes it all scientifically suspect.

But true skeptics won't let the fact that peer-reviewers won't publish it rule their judgments, right?

Have you checked out any of his references?

I found that Edwards/Milloy were just making stuff up. Sometimes they report stuff contrary to the author's conclusions, and sometimes they just make it up wholesale.

Two examples: On eggshell thinning, they report the work of DeWitt at 180 degrees different from what DeWitt reported it. See here:

And they claim that eagle numbers increased in the Audubon Christmas bird counts, from 1941 through 1960 or so.

There is no such claim from Audubon in any issue discussing the bird counts, from 1935 through 1975. There are at least 24 stories noting the decline of eagles.

Have you checked any of the citations, and found them accurate?

Ed Darrell, Dallas, Texas
November 2, 2010 4:25pm

I smell a rat, or maybe a dead bird.
I agree with Brian more often than not, he has opened my eyes to obvious fallacies on more than one occasion and sometimes I disagree with him.
But this episode, is like an april fools episode. The only missing reference is wikipedia.

Matthew Sparks, Sacramento, CA
November 2, 2010 7:21pm

Hi Brian,

Changing format of the podcasts to an audio only movie clip is not a good idea - it won't file with the previous episodes and can't be tagged/labelled.

Paul Coddington, Tokoroa
November 3, 2010 2:32am

Hi Brian

Thanks for this episode, it has made me revisit this issue. I once had a lecturer that bemoaned the banning of DDT on very much the same grounds as you have done...and I disagreed because I too had read the book Silent Spring. It's hard being a skeptic and having to revise long held beliefs, hey it's all part of the growing process. Even WHO has had a rethink.


Gina McCluskey, Dundee, Scotland
November 3, 2010 3:11am

"Feel free to point out any flaws you find, I'll happily correct them."

Here's one: The annual death toll from malaria is less than one million, not three million, as you claim in the episode.


Three million is the number from the height of DDT use, IIRC.

Of course as it's recently been discovered that India's malaria deaths are 200,000 rather than the 15,000 previously reported means that might be slightly wrong. I guess that being the world's biggest user of DDT to control malaria isn't working out that well for them...


Indoor residual spraying to keep mosquitos out of houses is a great idea (and commonly done in Africa). Along with bed nets, it's the best strategy we have against malaria. But we can't use DDT to blanket-kill mosquitoes and expect that to work. If you kill every mosquito in Africa without also curing malaria in the human hosts, then the mosquito predators will also die (from starvation or DDT poisoning) and when the next mosquito season begins, you'll get far more mosquitoes, who immediately get malaria from the human hosts, and the cycle begins again...

America defeated malaria by treating the disease in humans *before* DDT was invented. In fact, DDT has never been credited with effectively eliminating malaria.

wintermute, Cincinnati, Ohio
November 3, 2010 5:08am

In a couple of cases, Brian went even further than JunkScience. Was he just pulling the claims out of his ass or from another source.

Example 1. JunkScience says that "An epidemic of Newcastle disease [caused by the migration of sick pelicans] resulted in millions of birds put to death to eradicate the disease." Most likely those birds were poultry, but Brian assumed they were pelicans when he said, "an outbreak of Newcastle Disease in 1971 that unfortunately required the culling of millions of brown and white pelicans." (There are 300,000 brown pelicans in the world.)
Scientific and government sources primarily blame DDT for the decline of pelicans.

Example 2. JunkScience mentioned that stress is associated with eggshell thinning in poultry, but Brian went further to suggest that this factor skewed science experiments when he said, "Perhaps most significantly, birds in captivity in order to undergo testing are under stress, and this stress alone is enough to produce eggshell thinning." Where did he get this?

Max, Boston, MA
November 3, 2010 6:17am

Oh, and you cite Amir Attaran as an expert on how to fight malaria. Dr. Attaran works for (and was speaking on behalf of, from what I can tell) a group called Africa Fighting Malaria.

And yet, for some reason, AFM don't actually do anything to fight malaria in Africa, other than advocating indoor residual spraying (just as Rachel Carson, the WHO, the UN and the Gates Foundation do) and complain that environmentalists are all mass-murderers.


wintermute, Cincinnati, Ohio
November 3, 2010 7:17am

Another excellent post. I should email this to my Dad.

Pam, Southern California
November 3, 2010 8:23am

"Such wealthy donors have often had little personal exposure to the issues, and can sometimes have a skewed perspective when it comes to bald eagle eggshells in the United States versus the deaths of children in Mozambique."

Did you actually examine the strategies and goals of such donors, or did you simply take Molloy's word for it that they were opposed to DDT?

For example, the world's largest anti-malaria fund comes from the Bill & Melinda Gates Foundation. Their long-term strategy is to develop a cheap and effective malaria vaccine, but in the mean time, the short term strategy is a combination of indoor residual spraying with insecticide plus bed nets impregnated with insecticide.

Want to take a guess which insecticide they're using?


wintermute, Cincinnati, Ohio
November 3, 2010 10:49am

<blockquote>And so, again, we're outside of science questions, and down to risk assessment.</blockquote>

DDT was found to kill entire ecosystems with regularity, and in such a fashion that it cannot be used safely out-of-doors. That's why it was banned for spraying on crops in the U.S.

The U.S. ban did not extend to any other nation (EPA authority travels only so far as the U.S. borders), plus the order expressly left available manufacture for export to Africa and Asia.

In 1970, the National Academy of Sciences wrote about DDT that it is one of the most beneficial substances ever synthesized -- they goofed and attributed 500 million lives saved to it -- but said that its harms outweigh the benefits, and DDT use must be stopped.

Is there any indication that more DDT would provide more benefits, anywhere on Earth? Fighting malaria? Why do no malaria-fighting organizations ask for more DDT? WHO, the Gates Foundation, governments in Africa -- no one asks for more DDT.

There is no body of research that seriously and accurately calls into question any part of <i>Silent Spring</i>.

What makes you sure the malaria fighters and scientists are in error? Stephen Milloy?

Ed Darrell, Dallas, Texas
November 3, 2010 1:30pm

You know... one of the first times I felt a pre-emptory cringe from a title.

Brian, from the spate of entomology experts coming on line and talking about this and from the huge amount of journal articles (not convenient snippets on google) you are again presenting the better argument
(even if you didnt post these references....).

Well done. I bet you get a lot of folk posting their favourite google second's read.

If Andy Warhol had known about Google and its misrepresentation he would have reduced that 15 minutes!

Mind you, I would appreciate it if you posted all your references rather than the few here. You are going to get a lot of critique from folk with just a few references as well.

Henk van der Gaast, Sydney
November 3, 2010 2:01pm


"Want to take a guess which insecticide they're using?"

The Gates Foundation strategy you referenced doesn't mention DDT by name, so this really is a guess. The strategy talks more about funding the research and development of new vector control tools than about funding the continued use of existing ones.

Max, Boston, MA
November 3, 2010 3:33pm

Can anyone show that there has ever been a shortage of DDT, anywhere, especially for use against malaria?

When the U.S. banned DDT use on crops in the U.S., it dedicated 100% of DDT production for export. DDT is produced in great quantities today in India, China and North Korea -- India is the world's leading producer, and India uses more DDT annually than the rest of the world put together.

And you know what? India has continuing problems with malaria.

DDT doesn't work well to beat malaria. It's no magic bullet. It's no panacea. No nation using DDT as its chief tool has ever been able to vanquish malaria. Malaria was beaten in most temperate nations before DDT was available, and DDT was useful ONLY in temperate nations as a final blow, after much other work.

Stick to the facts, please. DDT is the wrong answer to almost any question, but especially to the question "What do we do about malaria?"

Ed Darrell, Dallas, Texas
November 3, 2010 4:22pm

DDT was not outright 'banned', even in the United States - it was banned for agricultural use, which happened to be it's almost exclusive use in the United States at the time the prohibitions were enacted.

This has been much more helpful than detrimental for combating malaria as liberally spraying DDT for agricultural purposes has been a major contributor in creating mosquito resistance to the chemical. Use of DDT for residual indoor spraying & bed nets has continued after the ban (except where more cost effective strategies have been developed; in Indochina, for example), and as far as I'm aware, has never been criticized by environmental organizations.

I don't know why the United States prohibition against agricultural use would be in need of a 'tune up'? Lifting the ban certainly wouldn't impact malaria mortality rates in Africa. If you dislike what the Gates foundation does or doesn't spend it's resources on (I find it dubious that they would not be using DDT where it would be effective, but I'll give Mr. Dunning the benefit of the doubt), take it up with them rather than railing against environmental groups (everyone's favorite scapegoat).

Kevin R Brown, Calgary, AB
November 3, 2010 6:09pm

the earth should be the judge wether or not chemicals should be used. if it does not agree with the earth, it should not be used. the earth is far more intelligent then we could ever imagine, everyone hypes about the global warming and we are killing the earth....what a joke the earth will be fine, however the earth will kill us off with floods and natural disasters so it can servive, for we did not respect it enough. us people are actually debating wether or not to use harmful chemicals is really stupied.....

heather, nova scotia, canada
November 4, 2010 4:20am

" if it does not agree with the earth, it should not be used."

I'm curious, what does this mean? DDT wont' cause floods, or most other natural disasters--at worst it could cause an ecological collaps, but that's not really anything new. I mean, while some people like me may personify the Earth for poetic reasons we acknowledge that it's not REALLY an intelligent entity. It's just a ball of rock, mud, water, and air, flying through space, just like any other planet.

Gregory, Alabama
November 4, 2010 4:17pm

If the Earth were intelligent, then birds instead of mosquitos would evolve resistance to DDT.

Max, Boston, MA
November 4, 2010 7:00pm

We haven't spoke since I saw you at TAM 8, but I have to say this episode is why I keep listening to this podcast. I have slightly preconceived notions that science is good, yet at the same time hold that some chemicals just shouldn't be introduced into the environment willy nilly. You take those two ideas and you prove how DDT is not harmful enough to risk the lives of millions of people on not using it, and add the third sensibility of kindness too those in need, and you have me in perfect agreement with you but completely disagreeing with myself 30 seconds ago. Wow, just amazing stuff. Thanks, keep it up!!!!

Eliot Silbar, Orlando
November 4, 2010 9:58pm

Good critique Brian.

As a physician and scientist I would have to concur with your summary. DDT ands its metabolite DDE are definitely guilty of unintended and serious environmental damage. Measure the benefits versus the long term damage.

As the first world elite sip their latte and prohibit its use in Africa over a million children die in Africa annually from conditions like Malaria that DDT can prevent. The closest the USA comes to noticing its absence is the proliferation of bed bugs.

DDT should be used where it has the greatest benefit for humanity. Furthermore its use should be carefully monitored to prevent overusage.

Thanks for a stimulating episode.

Ted Ledner, Sydney Australia
November 5, 2010 1:38am

Brian's claims about DDT resistance are also questionable.

"Susceptibility in resistant strains goes down to 63%, as opposed to 87% in non-resistant strains."

This comes from Wikipedia, citing a 2002 study in one province of South Africa. The study concludes, "Finding DDT resistance in the vector An. arabiensis... indicates an urgent need to develop a strategy of insecticide resistance management for the malaria control programmes of southern Africa." It does not conclude "Spray more DDT!"

Brian concluded that "Even among resistant mosquitos, DDT is an exceptionally effective repellent. Houses treated with DDT are avoided by all mosquitos, resistant or not."

This is similar to a JunkScience claim that Bug Girl addressed here: http://membracid.wordpress.com/2007/06/13/ddt-malaria-insecticide-resistance/
"Some mosquitoes shifted their behavior to rest in bushes, or on the outsides of homes. Obviously, mosquitoes that have the 'bite and run' trait will quickly increase in the population..."

Max, Boston, MA
November 5, 2010 5:19am

When farmers etc use pesticides they rarely use just the indicated amount. People tend to go overboard when applying the stuff. Also the word stress is meaningless. If environmental pressure is being put on birds wheather through ddt diretly or becasue of the food supply being decimated it leads to the same result.

Robert Mcbride, Columbia, MD
November 5, 2010 5:31am

Ddt is like any other chemical with serious possible side effects. It is put under careful control and used where it has best effect at least risk. For spraying mosquito nets and some other uses it is great.

A lot of the scaremongering, although not underexagerating the dangers seems to assume that DDT is unique in a lot of aspects. There are pleanty of the percieved dangers that are just as present in the more effective pesticides you will find in your local farm (and yes that includes the organic variety). The important lessons learned from DDT was in the field of controling hazardous substances effectively and enforcing the laws that protect personal and environmental safety.

Tom H, Kent, UK
November 5, 2010 8:12am

Another debunkatron rears its ugly head.

P.S.: Great episode =)

Pablo Colombo, Buenos Aires, Argentina
November 5, 2010 1:38pm

Another example of Brian going further than JunkScience.

Brian quotes Attaran as saying, "More than 200 environmental groups, including Greenpeace, Physicians for Social Responsibility and the World Wildlife Fund, actively condemn DDT," and leaves it at that, but even JunkScience acknowledged that "The World Wildlife Fund and Greenpeace apparently have reversed their long-standing opposition to the use of DDT to fight malaria." Another example of Brian going further than JunkScience.

Brian quotes Attaran as saying, "More than 200 environmental groups, including Greenpeace, Physicians for Social Responsibility and the World Wildlife Fund, actively condemn DDT," and leaves it at that, but even JunkScience acknowledged that "The World Wildlife Fund and Greenpeace apparently have reversed their long-standing opposition to the use of DDT to fight malaria." When was this long-standing opposition?

Max, Boston, MA
November 5, 2010 4:18pm

gregory, ....
"Is the Earth intelligent?"
who or what is the cause of the earths cycle? for the earth to nourish its soil, so it can feed the plants, for the bees to ploinate the flowers.... for us to survive. i just think that it is amazing how he earth and all the cycles co-inside with each other. .....i dono, is global warming caused from us polluting the earth? i believe it may...and it may not....entity? isn't EVERYTHING, when broken down to the smallest atom the the same thing? i think everyting should be given respect, spraying chemicals that kill anyting should not be used......
ohhhh max, that is really funny, seriously ...really made me think...i guess we have nothing to worry about, because us humans will eventually get immuned to it, we just have to wait til it kills a couple of generations, with cancer, immune problems...whatever....

heather, nova scotia, canada
November 5, 2010 5:10pm

The big picture is that Brian often debunks scaremongering (see any episode filed under Health or Environment), but I don't recall him mentioning the denial industry's doubt-mongering with the purpose of increasing corporate profits by stalling regulation.

This episode presented yet another opportunity to debunk both scaremongering and JunkScience's doubt-mongering, but instead Brian portrayed JunkScience as being more reasonable and better informed than the real experts.

The real experts say that the spraying of DDT should be "greatly reduced."

"A panel of scientists recommended today that the spraying of DDT in malaria-plagued Africa and Asia should be greatly reduced because people are exposed in their homes to high levels that may cause serious health effects."

Max, Boston, MA
November 5, 2010 6:45pm

Heather, if sprays that kill anything should not be used, then we wont be able togrow crops,fight infestation, clean our kitchens and run hospitals. Even organic farmers use pesticides to kill insects (and they use more than regular farmers because the organic kind degrades quicker so requires additional sprays).

Secondly the controling factor in the coinciding cycles of the world is the earth, tilted on an axis, cycling the sun in an eliptical orbit. Nature is amazing and beautiful but is not sentient or intelligent.

Tom H, Kent, UK
November 5, 2010 11:16pm

Dunning implies that DDT resistance doesn't hinder very much its use against malaria, but the disastrous experience of Sri Lanka in the 60s proves otherwise. DDT spraying had reduced malaria by so much in 1963 that there weren't another cases to justify spraying against malaria (though DDT continued to be used in agriculture). Unfortunately, malaria returned and when they resumed anti-malaria spraying DDT had lost much of its effectiveness because the mosquitoes had evolved resistance. By 1975, DDT was pretty much useless and they were only able to get malaria back under control by switching to the more expensive malathion.

More details and reference here:


Tim Lambert, Sydney, Australia
November 6, 2010 10:09am

tom, years ago before pesticides, plants had their own natural defence against pests, spraying had cause our plants to lose most of their nutritents and minerals from the soils, this may not seam like much to some but we are lacking all these vitimines, to fight off diseases our bodies were designed to fight off...these pesticides are killing our bees....this is not ok.....
oh just wonderin' who or what controls the earth? who do you give credit to for this amazing world to?
: )

heather, nova scotia, canada
November 7, 2010 5:02am

Yes, plants have their own defences against insect predation. But they haven't gone away; they were just not very effective in the first place. Pesticides have increased the yield of farmlands simply by being far more efficient than the crop's own defences.

Pesticides don't affect the nutritional content of crops (though selectively breeding strains that are uniform in appearance and last a long time on the supermarket shelf might). In fact, you're more likely to get more vitamins than your body can deal with than so few that it has deleterious effects.

There are many theories about what causes Colony Collapse Disorder (http://en.wikipedia.org/wiki/Colony_collapse_disorder#Possible_causes_and_research) and, yes, pesticides are a possible cause, but there's far less evidence to support that than Varroa mites or Nosema fungal infections. It's premature (at the very least) to suggest that pesticides are definitely the cause.

wintermute, Cincinnati, OH
November 7, 2010 6:25am

I'm still disturbed by the approving use of junk science found at the Junk Science site.

That's not skepticism. It's either sheer gullibility, or conniving prevarication. It's not thinking, and it's not honest.

Ed Darrell, Dallas, Texas, USA
November 7, 2010 7:22am


Brian seems to have a blind spot for these things.
The episode on plastic bottles references PlasticsInfo.Org ("Better Living with Plastics").
The episode on high fructose corn syrup says the American Medical Association is "not on anyone's payroll; they're an association of all of the world's best doctors, and their only purpose is to promote public health."

Max, Boston, MA
November 7, 2010 8:49am

Heather, years ago we were not trying to farm as large amounts of crop for harvest, nor did we have the same success rates at harvest. "Plants" may survive, but not the useful ones, or in the amounts the world needs. You know, for the small matter of feeding the population. Yes, it is unfortunate that the bee population is being reduced (more directly attributed to parasites than pesticides in the UK), but that is not an excuse to allow pestilence and infestation to sunder the worlds food sources. I have no interest in experiencing the Potato Blight first hand when there are moderate actions that can be taken to protect crops at minimal environmental impact.

Bees being dead is bad. Everybody I know suffering a slow death through hunger would be just as bad. Pesticides are needed.

I don't attribute anybody as being in "control" of the earth. Natural processes dont need to be controlled by a god, earth mother, or spirit of nature. Why do you feel so sure that credit should be offered to anybody? And if you think there should be credit given, how about you go ahead and prove the world is sentient?

Tom H, Kent, UK
November 7, 2010 11:03am

The environmental red flags against DDT have gone beyond the bird research you present. The concerns have expanded to DDT's environmental persistence, capacity to biomagnify and toxicity to higher trophic species (including, birds). Similar concerns have been brought up for other compounds, like PCBs and more recently, which has earned DDT a place on the Persistent Organic Pollutant (POP) list from UNEP's Stockholm Convention (see http://chm.pops.int/default.aspx).

True, DDT is not as bad ass as others on the POP list (aldrin and mirex, for instance, kick DDT's ass). However, DDTs inclusion on the list is not undeserved. From monitoring studies, DDT increases in concentration in remote areas from where it used, such as the livers of arctic wildlife. Thus, it becomes widely disseminated and is an additional stress global ecosystems have to deal with.

Couple this with numerous mechanistic studies demonstrating DDTs toxicity (alone or in mixtures with other POPs) to diverse wildlife, fish and birds (pubmed DDT toxicity wildlife / fish), there is reason to be cautious.

But, as you point out, DDT is not so toxic to humans, and it saves lives. We need it. Kind of like global chemo.

The question is how much is acceptable? This is what environmental researchers are actively pursuing. However, it appears that DDT currently is a necessary evil, and this is recognised by must (including UNEP); hence, a general caution. Still, alternatives are wanted big time.

Big fan!

Hans Peter, Oslo
November 7, 2010 3:38pm

I don't have anything to add but I would just like to applaud you for this blog. It's very informative and while you do state your opinions you're not radical. Instead you consider all aspects of an issue. Thank you for giving me something intelligent to read that actually gets me thinking. Once again, great job and keep them coming!

Locke... Wiggin, Greensburo
November 8, 2010 7:28pm

Tom, i have no intentions of proving there is a higher intelligence, because i can not prove it. it is just something i feel, and believe, to be true for me. it is more then okay with me what others think is their own truth.
with that being said, pesticides, i do have a huge issue with, i do not support using chemicals, my neighbor son was rushed to the hospital this summer after the weedman had sprad a couple of yards a couple houses down, he took an extreem reaction, which i realize may be rare, however after seeing what i had seen i do not think it would take a scientist to figure out pesticides are not be good for humans...

heather, nova scotia, canada
November 9, 2010 5:13pm

There is no such thing as "true for me" or one's "own truth". No one denies that people have subjective experiences, but those experiences are imperfect derivations of an objective, physical world. If a person has a belief that is in line with reality, then they're right. If their belief is out of line with reality then they're wrong. Determining which is which is where science comes in.

The claim that the Earth is itself conscious is an objective claim about what is true. Either the world is conscious or it's not. It can be tested, and as such is well within the purview of science. If you assert it, you must demonstrate it.

You also say, however, that you "feel" and "believe" it. Those are claims about your experience of reality. I don't think anyone would dispute them. Nor would anyone dispute that your neighbor's son had an averse reaction to some pesticide. But neither is evidence that should be considered in determining the practicality of widespread pesticide use. Neither has anything to do with DDT use in Africa.

Human perception is immensely fallible. You seem to be drawing conclusions about the state of the objective world based on your subjective experience.

Marshall, Smyrna, GA
November 11, 2010 9:34am

Indeed, decrying the tools of agriculture as wrong, based on subjective experience and what is "true to you" is a concern. As is stating that plants have grown for millenia with out pesticide or chemical aid. If feeding the world were so simple (and the same arguments aremade against gm crops, fertilisers, pesticides, fungucides and other treatments) then "dustbowl famines" and the potatoe blights would have been minor inconveniences.

The earth can not judge if pesticides or good or bad. We can not continue to exist with out either using them, or consigning the majority of the worlds population to starvation. So we are stuck where are at the moment, using reasonable measures to minimise the risks.

Sorry if that sounds hard hearted, but i need a better reason than religious belief in ghaia to justify the ramafications of decrying something as "evil" that even organic farmers rely on. To my mind it is not an ethical issue, it is practical. And trying to blame the decline of bees on a single cause is a vast over simplification. (And it ignores several more immediate threats to apiarists).

Tom H, Kent, UK
November 11, 2010 11:55am



Poison if swallowed. May be harmful if inhaled or absorbed through the skin. Absorption is considerably enhanced by the presence of oils. Possible human carcinogen. Human mutagenic effects. May cause reproductive damage. May act as a systemic poison. Toxic effects of this chemical appear to be enhanced when exposure simultaneously includes other chemicals.
DDT and its degradation products, particularly DDE, are stored in fat in the body, and this can lead to a total body load of chemical which is potentially much greater than the fatal dose. This stored material is removed only gradually from the body.
Environmental information:
A serious environmental hazard due to bioaccumulation and transport up the food chain. Concentrations in animals near the top of the food chain (such as predatory birds) may become high enough in areas in which DDT has been heavily used, to have devastating effects upon reproductive ability. Degrades extremely slowly in the environment and is removed very slowly from animal tissue....i'm just not a fan...

Tom, i just think we have enough intelligent people to come up with a better plan then chemical use...yes people are starving in other countries, but look at the countries we live in...it is grose how greedy we all are...just look at all the over weight people waling around sick from consuming so much food, i think there is plenty to go around...you make really good points for me to concider, however..im running out of

heather, nova scotia, canada
November 11, 2010 2:38pm

Brian, I'm very disappointed in this episode. As noted above, Junkscience is aptly named, and is a corporate cherrypicking site. Tim Lambert's Deltoid site has had many posts on DDT, noting that there was never a ban, that blaming Rachel Carson has been an interesting ploy started by Roger Bates, and identifying the high degree of misrepresentation about DDT use. And, it's all backed by the original sources, not secondary reports (some of which contribute their own errors). There's a nice tab to DDT posts, and links to the original, peer reviewed articles.

stewart longman, Calgary, Canada
November 13, 2010 11:44am

Heather, you say to look at all the over weight people as evidence that we have more than enough food. Unfortunately the excess of rich nations would not be enough to counter the massive deficits in poor nations that regurlarly suffer famine. South american nations are already having to deforest to support crops. If a (vastly) higer proportion of those crops failed, because they lacked chemical aid, then they would deforest further to compensate.
With out pesticides, etc, there will be more wasted crops and little to prevent blights from spreading. The demand for food will reach critical, and people will die.

Tom H, Kent, UK
November 13, 2010 12:15pm

Its good to see people dont use cars, electricity, water from dams and clothing.

You go to it Heather, I personally would like everyone walking around in the nude as you and I both know these are far worse for the environment than.....pesticides.

Tom may have a reason for covering up that remains to be seen 8-).

Henk van der Gaast, Sydney
November 13, 2010 4:22pm

i totally agree with you Henk Vander Gaast! LOL!! ;^)

heather, nova scotia, canada
November 13, 2010 6:09pm

Just because alternatives to DDT are currently too expensive does not mean they should not be actively and aggressively pursued.

And trying to tug our heartstrings by invoking "elitist stereotypes" and (gasp) children potentially dying seems like a weirdly emotional appeal from a so-called skeptic. It could, and perhaps should, be argued that malaria is effective human population control in places where, for political reasons, other mechanisms don't exist. It's extremely short-sighted for foreign benefactors to save third-world children from dying of natural causes without making sure all their future needs (education, food, clean water, immunization, etc.) are met. Saving all the babies perpetuates poverty and the enslavement of women. Let's worry about malaria AFTER we make sure every baby born is a wanted and well-cared-for one.

Elizabeth, Austin
November 16, 2010 2:58pm

phew... where is mother theresa when you need her.

what about all the other people who are educated, fed, living of natural causes drinking and vaccinated?

that was profound, profound tweet, bleep, bleep profaound...

Saxophone please Brian?

Henk van der Gaast, Sydney
November 16, 2010 6:36pm

I generally concur with Mr. Dunnings conclusions in his podcasts, but I strongly disagree with this one.

I happened to be reading 'Merchants of Doubt' by Naomi Oreskes, and she has an entire chapter of the book (Chapter 7 - Denial Rides Again: The Revisionist Attack on Rachel Carson) devoted to the issue of DDT.

Of particular note, among many, is the author's reference to a Lancet study: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2805%2967182-6/abstract

The conclusion: "...subsequent research has shown that exposure to DDT at amounts that would be needed in malaria control might cause preterm birth and early weaning, abrogating the benefit of reducing infant mortality from malaria...DDT might be useful in controlling malaria, but the evidence of its adverse effects on human health needs appropriate research on whether it achieves a favourable balance of risk versus benefit"

Sean Fisher, Milpitas
November 17, 2010 2:19am

Sean, that was a great argument well made as far the Lancett article goes (a good source and you stated it well) unfortunately the title of the chapter irks me a bit. I don't see revision of the safety guidelines for using DDT as an attack on the deceased. Such language smacks of agenda and bias swaying judgement before due consideration is given.

Now what the lancett said is right, when a significant risk is identified we do further study to assess the severity of the risk. That does not mean we blanket ban the use of the "evil" tool, we step back, look at the risk and work out how to reduce it to a minimal level. To my understanding this is exactly what has been done by the majority of those who use DDT to produce malaria nets.

Tom H, Kent, UK
November 17, 2010 9:49am

If anyone's interested, the "Drunken Skeptics" podcast interviewed Brian and discussed this episode.


Chris Lindsay, Ann Arbor, MI
November 17, 2010 7:45pm

Tom, thank you for the kind words, and I would like to address the points you raise.

Point 1) The title of the chapter is apropos as Ms. Carson has been vilified in some quarters, for example

Rachel Carson's Genocide

Rachel Carson's Ecological Genocide

Rachel was Wrong

(Note: I have cherry picked these after a bit of googling as being particularly libelous)

I agree that critiquing a dead person's work is not an attack on that person per se, but ad hominem attacks are beyond the pale.

Point 2) I do not know specifically who, if anyone, you may be referring to who advocates a wholesale ban on DDT (Carson didn't BTW) -- perhaps you are referring to the 2001 Stockholm Convention?

Anyway, I agree with your logic about weighing benefits vs. harms (including with DDT), but the efficacy of DDT for malaria control is certainly not as clear as Mr. Dunning presents in his podcast, and I find his statement about environmental groups and brown people to be an unjustified ad hominem attack in its own right.

Wikipedia has some good info on DDT, including its mixed record in malaria control.


Sean Fisher, Milpitas
November 17, 2010 8:11pm

My point about a wholesale ban was in reference to previous posts by Heather in this thread, who wants not just DDT, but all pesticides to be removed from common use. Or rather she seems to based on the statements she made in this discussion. she is far from alone in these sentiments if you go looking for the same anti-"Big farming" groups on the net. I did not intend for it sound as though you were postulating that response and should have worded my response with more care. Sorry.

Tom H, Kent, UK
November 18, 2010 8:13am


First of all, you completely changed the subject. My point was more that you made claims about the Earth being conscious and that your understanding of the nature of truth is flawed. You didn't address either of those points, can I assume you have conceded them?

What you did address, though, are the dangers of DDT. I don't think anyone is denying that DDT has some harmful effects. It does. The question that remains is: "Given its level of harmfulness, is it the appropriate tool to use to solve any problems?" That question is up for debate, and I don't have any strong opinion on it. You seem to think that it is far too harmful to use for anything, and that seems short-sighted. That opinion also seems to be derivative of your strange allegiance to anything labeled "natural".

Nonetheless, it boils down to a value judgment, and science doesn't have anything to say about value judgments. You are entirely free to value a naturalistic ideology over everything else, including human life, just so long as you don't use it to make claims about objectively testable truth.

Marshall, Smyrna, GA
November 18, 2010 10:36am

Just a clarification...
"...the U.S. Environmental Protection Agency classifies it as a "probable carcinogen". The claims that DDT definitely causes cancer or anything else are not supported by the data, but obviously it's a risky compound that we don't want to expose anyone to if we don't have to. And so, again, we're outside of science questions, and down to risk assessment."

In EPA's eyes, a ranking of "probable carcinogen" is on the more certain end of the assessment scale (i.e., EPA is pretty much convinced that it is carcinogenic, but they are acknowledging the uncertainties inherent in the toxicological assessments). Few chemicals are given a definitive ranking as a health hazard.

Also, EPA considers "risk assessment" to be a scientific process (i.e., quantifying risks based on specific exposures and the available tox info). "Risk management" is the term they use for the cost-benefit evaluation you were referring to.

Jim R, Portsmouth NH
November 18, 2010 2:28pm

Ted Ledner-

Sorry that someone who self-identifies as a physician and scientist would fall into such lazy strawman arguments as the cartoon of the "first world elite latte sippers", and that DDT is effective against bedbugs. DDT had lost it's effectiveness against bedbugs well before it's use was restricted in the 70's. And "first world elite" stereotypes are no more useful than the tap-dancing watermelon eating variety in rational discussion.

Kerry Maxwell, Arlington. MA
November 21, 2010 8:28pm

DDT are F-ing kidding me! This is what you choose to be skeptical about. I knew your weren't a big advocate of the environment by your SUV and other episodes but bring back DDT.Whats next week? The safe use of Agent Orange or clubbing baby seals?

David Held, Newtown PA
November 22, 2010 3:05am

Brian Dunning wrote in comments:
"Feel free to point out any flaws you find, I'll happily correct them.

I'm not sure your political disagreement with one of my sources constitutes a valid correction to anything in the episode."

well <a href="http://http://scienceblogs.com/deltoid/?utm_source=bloglist&utm_medium=dropdown/">it's been done Brian</a>, where is the correction? Wow, you really stepped on your dick this time. Here is a clue, not all people who care about the environment fit your ridiculous stereotype and you may want to be a little more thorough when researching environmental claims given your obvious bias. It would be a shame to have to boycott a decent podcast but your lack of follow up and correction when faced with better evidence is very troubling.

Justin, Golden, Colorado
November 22, 2010 11:56am

Ahh, after quoting Milloy and getting busted for it, Dunning trots out the "false equivalence" card. "Nice." That's what the monkey-wrenchers do, whether the money is more from Big Tobacco or Big Oil.

I think Tim Lambert at Deltoid is you, at least in some cases, are apparently a corporate shill, how can you really be that good at "debunking pseudoscience"?

Instead, you come off like Shermer — another compartmentalized skeptic at best, pseudoskeptic at worst. (Actually, Shermer's got worse problems than that: http://socraticgadfly.blogspot.com/2010/11/is-michael-shermer-racialist.html)

As for not only DDT in particular but chemicals in general vis-a-vis malaria, we built the Panama Canal with the assistance of sanitation engineering and other mechanical measures; not a drop of spraying involved.

DDT is overrated in general. And, as "Merchants of Doubt" notes, ANY chemical assault on malaria, by itself, will fail, without accompanying sanitation measures.

SocraticGadfly, Earth, United States, Odessa, TX
November 22, 2010 2:10pm

"Feel free to point out any flaws you find, I'll happily correct them."

...so any intent to follow upon this, now that numerous flaws have been pointed out?

Neil, BC
November 22, 2010 2:21pm

There seems to be an attack on his source and the defence is what bits are wrong.

Another way may be to ask could this be written using sources such as papers from Nature or Science and reports from WHO?

I don't think the claims made here could be backed up by those sources thus it was required to go to sources that make things up but have a similar political attitude to the author.

David McRae, Canberra, Aus
November 22, 2010 5:05pm

Tim Lambert has written part 1 of a post at Deltoid responding to this podcast. It's worth noting that going back from Junkscience to the primary sources, most of what's in Junkscience is not supported by the primary literature.
Your thoughts, Brian?

stewart longman, Calgary, Canada
November 22, 2010 5:52pm

Excellent point, David (McRae).

If a source for a claim is known to be controversial - and Brian surely cannot be ignorant of the controversies surrounding Milloy and his site - why not look for a less controversial source to support that claim instead?

And if one cannot find a non-controversial source for a claim, that should at least raise the red flags in one's mind as to the reliability of the claim itself.

Mick, Canberra
November 22, 2010 6:40pm

I e-mailed Mr. Dunning the url for a New York Times story about DDT and its continued apparent impact on condors in the western U.S. He asked me to post it here, so here goes: http://www.nytimes.com/2010/11/16/science/16condors.html. Hope it provides some interest.

Andrew, Seattle
November 22, 2010 7:07pm

It gets even easier guys and I really don't know how to emphasize this here on skeptoid. I have tried often enough but it always come down to; "look at this site/reference, I must be right!".

Just search within scholar for the last 2-5 years worth of articles on this topic.

You will find a lot of measurement reports (the sort of thing I like to peruse) and a hell of a lot of review articles.

The consensus position is maintained by review authors constantly rewriting their view of the state of play w.r.t. the measurement articles.

There is a caveat. Review is a licence to place opinion into print. You would have to read a fair few of the review articles to get a good grip on the current thought on the matter.

Now here is where Brian is totally correct. Rachel Carson's "Silent Spring" is a book. It is a book written by a person.
As good as it may be, its not scientific literature, its a book of personal review.

I may add it was out of date when published.

If you are going to live or die by the sword, go to the smith to work out which sword is the best. Otherwise someone, somewhere may just be handed a sword that suits S/him better.

The same goes for Journal articles.

Henk van der Gaast, Sydney
November 22, 2010 7:08pm

This article is not an exercise in scepticism - it's a demonstration of how to get duped by nonsense when you don't do proper fact checking.


DavidC, London / England
November 22, 2010 7:23pm

gee what did I just write about people pointing to a site or article and saying "Look I am right"?

Looks i have proof positive that I am prescient... I'll take the money from JREF and split it with Brian.

After all, he could pull these last two ruining my chance at the mula!

Henk van der Gaast, Sydney
November 22, 2010 8:24pm

I hope Brian Dunning is taking seriously the critique of this column by Tim Lambert ( http://scienceblogs.com/deltoid/2010/11/skeptoid_fact_check_part_1.php ), who's spent a lot of time and effort over the years studying the science and politics of DDT.

One thing I know from my own experience is that as few references as Brian has given above to original scientific literature has never proven sufficient for me, personally, to proclaim myself a "skeptic" of any contentious issue in the sciences.

frankis, sydney, australia
November 22, 2010 10:14pm

Frankis, that is my first commentary on Brian's original Skeptoid on the subject.

As far as I know there is only one contentious issue in science at present; the way to get politics to get more science into the masses.

At present the average politician is very average when it comes to science. From what I see, the higher you rise in politics the more credulous you write your propaganda.

Every western country I know of has an entire range of rubbish to cater for brain rot.

Brian (who doesnt pay me or know me other than my sometimes disparaging comment), does a fairly good job when compared to many media reps.

You and I in Oz do not have to go far to see the zeal for alt modalities in the media and disgracefully so, our flagship science show on the ABC will trot out the woo in medical science over hard grind medium level (but really good stuff) boring chemistry.

If anyone should be a real political commentor on the sciences then the woo should be crucified day in and day out.

Frankly the very best religious show that has appeared in this country has driven religious woo to run and recover. Why cant politicians remove this rubbish from insurances and street front snake oil advertising?

It's popular.

Truly, in this day and age we require conscience votes for a therapeutic agent, biochemistry and biology when it really should be a conscience vote on gullibility!

Thats why we have these votes in parliament.

Politics isnt hell, its working your guts out to get nowhere

Henk van der Gaast, Sydney
November 23, 2010 12:29am

"...so any intent to follow up on this, now that numerous flaws have been pointed out?"

Not according to his interview.

"I don't think there's anything in the DDT episode that needs to be corrected." -Brian Dunning

Says he asked for corrections but all he got was objections to Milloy's voting record. I for one don't know Milloy's voting record, I know his anti-science record.

Max, Boston, MA
November 23, 2010 1:10am

Thank goodness I noticed a comments log. It was rather inconsiderate of Brian to allow this sort of comment on the issue.

Pi, pi=3, yes lets have another raging debate on the lack of references on that one as well.

From what I see of the review articles that are current, Brians commentary isn't very far off the mark.

I just wish time and other resources could have filled the references for this show a bit better. Its a topic (similar to nuclear reactors) that has a lot of folk standing on their head after talking about it at the shop, the pub or reading a google site.

If he had have said an obviously dumb thing, there are plenty of punters who would have weighed in.

Henk van der Gaast, Sydney
November 23, 2010 1:23am

It seems a lot of the criticism is from people who never finished the episode. His concluding paragraph was pretty clear that except for Africa, where there is a major malaria problem, the current DDT policy is probably right where it should be.

Is that really that "contreversial" ?

Shane P. Brady, Plattsburg, MO
November 23, 2010 4:26am


Henk van der Gaast, Sydney
November 23, 2010 4:31am

The quote that Greenpeace "actively condemn[s] DDT" is misleading. Greenpeace does condemn agricultural use (as was banned on the Stockholm Convention) but my understanding is they have never called for a ban on DDT for malarial control. From their website:

"DDT was never banned for use as a malaria preventative.

We support the continued use of DDT in malaria control programmes where there are no effective alternatives."


Crust, USA
November 23, 2010 7:07am

With fish populations, water tables, soil fertility, etc threatening the 6.5 billion already rooting around for scarce resources, explain to me again why we need to release DDT. Ohh to make even more people. Yea go team go.


Mike, Federal Way, WA
November 23, 2010 8:16am

@ Brian: “I've gotten a lot of criticism for including a link to the JunkScience.com web page.”
Thanks for the clarification, Brian. But the criticism isn’t that you *linked* to Junk Science; the criticism is that you seem to have *relied* primarily on Junk Science for much of your information. If that is not the case, I think it would be hugely helpful if you clarified what sources you actually did use for those claims that have been challenged. Please list some of the "HUGE number of studies" that you say contradict the scientific consensus. I know you have a limited time to research each podcast, but seriously, dude - your credibility is on the line here.

Scott Field, Denver, CO
November 23, 2010 8:28am

"The errors that have been pointed out to me so far are not, in my opinion, significant enough to alter my conclusions."
Dude, seriously?

Here's the problem -- the conclusion "DDT regulation is probably about where it should be" is not itself a problematic conclusion. However, you got there using some very wrong assumptions and "data" -- and for debunking purposes, this is not ok.

Have you seen this? Obviously part II isn't up yet, but this points out a lot of problems (some of which I'd noticed myself).


I'm going to add, even basic checking of your sources would have shown you that Steve Milloy is not only "libertarian", he is also a 9/11 Truther, and before that was one of the very scientists previously employed by Phillip Morris to use a disinformation campaign to cast doubt on the issue of tobacco's impacts on health. Either one of those things really ought to have raised a lot of red flags for you, and you really shouldn't have used him as a primary source for much of this (as you clearly have) without digging deeply into his assertions.

What Scott Field says: your credibility is on the line, here. You made a bad call about data and a data source; to retain respect, I think it would be worth it to revisit this in full.

Lynne, Scotland
November 23, 2010 8:49am

"[M]y opinion is that donors should relax their restrictions against [DDT], and leave those decisions to the experts on the front lines in Africa."

Note that (contrary to what I take to be your insinuation) DDT is currently being used in several African countries (including Madagascar, Ethiopia, Eritrea, Sudan, South Africa, Namibia and Algeria).


This is an earnest question: Which specific donors (if any) forbid the use of DDT?

Crust, USA
November 23, 2010 9:15am

@ Lynne: Yes, Brian has seen it, and in fact posted a comment there this morning. (He basically says he never quoted Malloy, had never heard of Malloy before, and only listed him as a reference for completeness/balance.) What he (Brian) hasn't yet done is address any of the substantive criticism.

Scott Field, Denver, CO
November 23, 2010 11:14am

Mike, so with the aquatic life you would like pyrethrin dumped everywhere?

Its just as natural as DDT as well.

Henk van der Gaast, Sydney
November 23, 2010 9:27pm


Making corrections in a "Things I'm Wrong About" episode is a step in the right direction. Make sure THIS page links to it, or better yet, revise THIS page, because this is the page that others have already linked to and tweeted, and that shows up in Google.

You can revise the episode by crossing out errors and inserting corrections in a different color, the way Robert Carroll revised his newsletter on secondhand smoke.

Had you referenced JunkScience to debunk it, this episode might have been unbiased, but instead you parroted JunkScience's denialism.

It is possible to find interesting info even from very biased and disreputable sources, but you have to vet the hell out of it.

Max, Boston, MA
November 23, 2010 10:07pm


Just a few thoughts: I used to work for a big multinational who invested in huge industry in Maputo, the capital of Moçambique. When we arrived, there were approximately 50 to 60 deaths PER DAY, in a relatively small part of the city where the industry was going to be located. (PER DAY). An active anti-malaria program was initiated and after about two years, that figure were down to about 20 to 30 deaths PER MONTH. A huge part of this was due to DDT.
The problem was that the donors from the USA were not interested in investing money if DDT were used. Basically it is an overactive guilt trip for them. the US eradicated malaria in the 60s by crop spraying the stuff, but if we want to use it in Africa selectively by spraying houses to actively save lives, the money dries up.
I am not saying that it isn't a scary chemical. Just that it currently works in Moçambique. If the US manages to ban it globally, they will be actively killing people not as fortunate as them.

just a thought. use it, don't use it...

Herman van Vuuren, Johannesburg, South Africa
November 23, 2010 11:40pm

Herman, some sort of publication please.

Henk van der Gaast, Sydney
November 24, 2010 2:16am

Brian - you should be aware of the deliberate campaign by right-wing lobby groups to discredit environmentalists by spreading disinformation about DDT. You should be very careful to check such sources before repeating such information. There's a world of difference between campaigning against use of DDT in agriculture, where it is spread by the tonne and quickens the evolution of resistant mosquitoes, and the use for disease control. Environmentalists have not campaigned against it for that purpose, and it is in fact overuse of DDT that has compromised its effectiveness for use against malaria. There never was a worldwide ban on DDT for disease control.
You should include Tim Lambert's response to your podcast in your recommended reading:


Dean Morrison, Hastings, UK
November 25, 2010 5:30am


I really hope that you dedicate an entire episode to correcting ALL of the errors you made in the episode, not simply a throw-away non-admission admission in a "Things I'm wrong about" episode that only addresses a single point.

I think it's important because I have come to respect your clear intention to keep your personal politics out of Skeptoid (even though they sometime seep through).

It this case, I was not even aware of the full extent of this controversy -- nor the extend of the misinformation your presented in this episode -- until I read the criticism on other skeptical blogs and forums (skepchick, SGU forums, etc).

I think this actually could be a great example of how the skeptical works, of why we can generally trust what "skeptics" say: when one of us messes up, others point it out, and corrections are made. Please maintain your skeptical credibility by making a full & complete correction.

Febo, Manchester, UK
November 26, 2010 5:40am

Goodness Brian.. you are a disingenuos bugger.

Not having enough ref's was a drag.

I am however a bit confused by the sudden expert attack by critical thinking folk on a biological and historical issue as indicated by FEBO (no I havent noticed Steve and the guys raining vitriol on your post either).

Personally, I dont know what the effectiveness of the compound is for anopheles (it appeared to have fallen off for on cover areas by 1961).

But, If there is a better insecticide, IT SHOULD BE USED.

Otherwise, spray baby spray whilst these hypocrites drive their cars and use gas and electricity for lighting and home power.

After all, what is worth by many many orders of magnitude?.. Being a hypocrite in the west.

The case for not using DDT is not obvious.

All of the above naysaying is "Bilderberg conspiracy", TC Brian

Henk van der Gaast, Sydney
November 26, 2010 6:45am

You seem to have thought this through before concluding that DDT is the only solution for curing malaria in Africa. DDT is indeed a powerful chemical, there is no doubt about it, and it is therefore equally dangerous. In America, it's dangers outweighed it's benefits, and it is for that reason that DDT was (in my opinion) rightfully banned. However, if it is possible to apply DDT in third world countries with minimal side effects, I don't see why not give it a try. The best way would be to test it in small areas at first and observe carefully what happens, then if safe, apply it to larger areas. Currently, South Africa sprays DDT every year as a mosquito controlling measure. It would be interesting to see what effects DDT has there.
Nevertheless, it isn't because we have a powerful tool (DDT) that we shouldn't seek for alternatives, there are plenty of ways one could fight mosquitoes without using pesticides. In Bermuda there are a series of laws that are aimed to controlling and even eliminating mosquitoes. Also, researchers are looking into methods such as the Sterile Male Technique, which consists in releasing a large amount of sterilized male mosquitoes into areas with malaria problems, and have them compete with the non sterile males. With big enough numbers, the population of mosquitoes would drop.
The point is, DDT is a great weapon for last resort, and I am not against it if it is used with care, but don't put all your focus on it.


Iman, Massachusetts USA
November 26, 2010 12:09pm

Wow. I've seldom read a more self-satisfied statement of utter, stubborn denial than the appendix to your post. I appreciate that you want us to read and "think for ourselves". Believe it or not, that's occurred to many of us. Thanks. That doesn't excuse your pedaling nonsense like this. You have got your facts profoundly munged, and, more than offering JunkScience merely as a reference to one of "both sides", you seem to get your major premises from there as well. Surely by now you have been made aware of the fact that there is absolutely no evidence "environmentalists" have played any role in increasing malarial deaths, so I assume your plan to correct a few minor errors while leaving your main conclusion untouched is ideological, not based in facts. I do read and think for myself, but I avoid sites that seem to have an agenda detached from reality, and I'm afraid I'll have to add skeptoid to that list. What a pity. Fortunately, there is a healthy and burgeoning community of skeptical and science bloggers online who are trustworthy and can accept reality, even when it conflicts with their cherished beliefs.

John Harrington, San Diego, CA
November 26, 2010 1:39pm

Hey, Brian:

Have you contacted Milloy yet to ask him to explain away how, although it **seems** secondhand smoke kills 600,000 a year: http://www.bbc.co.uk/news/health-11844169 this isn't really true?

Please, let us know what he says on your next "skeptical" podcast.

SocraticGadfly, Somewhere, Texas
November 26, 2010 6:23pm

John - If you look around you with a more attentive eye you would realize that nothing is too detached from reality. In a brief period of 200 years we've gone from sailing in wooden boats to landing on the moon. Medical advances are quickly progressing if you haven't noticed, and if every one would think like you we would never reach any goals. Who would have thought 20o years ago, that an atom could be split? There have been many trials and errors along the way, but it isn't by saying that some things are too far fetched that you could cure malaria. The beauty of science is that it can transform fiction into fact. I'm know that one day, AIDS will have a cure, Cancer won't be life threatening, and Malaria won't be an issue.


Iman, Massachusetts USA
November 26, 2010 8:52pm

Brian, I think you and Bug_Girl should really make a debate and have an open discussion about this topic.

You raised some very good points and she raised some very good points, but somehow you totally contradict each other.

Two known and appreciated skeptics that completly disagree, in my opinion, is a great way to learn how science is done!

Lucci, Tel-Aviv
November 27, 2010 3:32am

Tim Lambert has now posted the second part of his response to your article Brian.


You said you'd respond to corrections of fact, and it would seem you now have quite a long list of matters to address. When can we expect a reply from you?

Dean Morrison, Hastings, UK
November 27, 2010 7:06am

Seems this is degrading into "lookey here" posts again.

Henk van der Gaast, Sydney
November 27, 2010 7:22am

A very telling exchange:

Dunning comments: http://scienceblogs.com/deltoid/2010/11/skeptoid_fact_check_part_1.php#comment-2947797

Lambert responds: http://scienceblogs.com/deltoid/2010/11/skeptoid_fact_check_part_1.php#comment-2948423

Brian Dunning is taking on the appearance of someone who defines 'sceptic' as 'I refuse to believe the science and evidence'.

DavidC, London / England
November 27, 2010 7:48am

Just a reminder that among the many remaining errors are gross misrepresentations of the position of groups like Greenpeace and WWF. Of course, it's only coincidental that your primary sources are people who make their living attacking environmental groups (funded by a combination of businesses seeking less environmental regulation and rightwing tribalists).

John Quiggin, Brisbane
November 27, 2010 8:44am

I don't know the position of the WWF. As an environmentalist, I deplore the philosophy and the tactics of greenpeace.

I have denied their position for over twenty years as a non scientific muscle group. If they stuck to true envronmentalism they may just be palatable with some stunts. They appear to bee the bastard misdirected child of anti weapons technology of the late seventies.

Stunts achieve nothing, political force achieves everything. Now everything called "green" is suspect and tainted with a naturopathic bent.

The australian greens position and platform is anything but green, its fuzzy feel good get nowhere politics. Shame on them for not a single skerrik of leadership.

They do not present an understanding of science.

Henk van der Gaast, Sydney
November 28, 2010 12:10am

This whole kerfuffle has got me doing a lot of reading up on the DDT pseudo-controversy. Following links provided by these blogs and in their comments sections:

Orac's Blog: http://scienceblogs.com/insolence/2010/11/skeptoid_disappoints.php

Bug Girl's Blog: http://membracid.wordpress.com/2007/06/29/ddt-and-attacks-on-rachel-carson-the-cliffsnote-version/

Some Guy I've never heard of before's Blog: http://scienceblogs.com/deltoid/2010/11/skeptoid_fact_check_part_2.php?utm_source=sbhomepage&utm_medium=link&utm_content=channellink

This article about Rachel Carson: http://www.prospectmagazine.co.uk/2008/05/rehabilitatingcarson/

...and various links that those links linked to.

The overall impression I've been getting is that Brian is (hopefully inadvertently) repeating a common anti-environmentalist meme where they accuse environmentalists of being racist and interfering with disease prevention, and then they go on the admit that the current policies (which are supported by the environmental groups they just bad-mouthed) are just fine... but of course they conveniently forget to mention that the policies they are agreeing with are the exact same policies promoted by the "evil" and "elitist" environmentalists they were just accusing of being racists.

I sincerely hope that Brian was not doing this on purpose, and apologizes soon for getting this so wrong.

Febo, Manchester, UK
November 28, 2010 1:20am

Febo, get off your horse. Brian did nothing of the sort. Bug Girl has easily presented that DDT effectiveness fell off way before its disuse in many areas. She has quite often maintained that she doesnt know if DDT should be completely disused either. If this is not represented in her blogs so be it.

A key feature that Brian implies is that effective pesticides are maligned by the generation of discontents but too lazy to learn. Brian has maintained this for old and new technologies, super effective, less effective and phasing out.

The point is, beside DDT there isnt much at present for countries that are poor without any malarial control. DDT does appear to be a local pesticide still of note.

Finally, Brian gives each situation a fair go. You may not like his style, but then you would deplore mine.

He gets you talking, gets you looking around.

whoops, my pager for the homeopathic emergency centre has just gone off. Gotta run a tap.

Henk van der Gaast, Sydney
November 28, 2010 1:36am

This whole shitstorm reminds me of what we tell believers when they say "Skeptics are such meanies! My ideas ought to be treated with respect! WAAAAH!"

We sit them down and say "Listen, you aren't being treated especially harshly, you only think you are because your feelings are getting hurt. The truth is that scientists go after each other tooth and nail. Science is brutal and it can be painful when your idea gets ripped to shreds."

The people critiquing Dunning are responding to what they perceive Brian calling Environmentalists genocidal racists to be an ad hominem attack that is factually inaccurate on many different levels. Most skeptical podcasts use ridicule, snark and even occasionally insults, but they also always include valid logic and evidence. It their criticism, Orac, Lambert, and others provided loads of logically presented evidence demonstrating that Brian's presentation of the DDT pseudo-controversy was wrong.

Dunning should accept that this is part of the process by which scientific knowledge is discriminated. Skepticism is a full contact sport; don't step in the ring if you aren't ready to get hit, and if you are going to label people genocidal racists, you better be right about your facts!

Febo, Manchester, UK
November 28, 2010 1:51pm

I must have missed the bit about genocidal racists but yes I can see that point.

Its all to convenient to wage "environmental" wars of ideology on other peoples plots. You need only to look at the actions taken to prevent G.M. and other agricultural applications taken in other continents (asia and africa).

I take my cynical hat off to these guys who are perfectly happy to east far easier disseminated gm food products (and I wont name which as its my irony fix every day).

Its not confined to environmentalism. We westies are only far too happy to support our own well being from the misery of others in other countries.

I am sure most australian youth do not think for a second that sex tourism destinations in local countries is a bad thing at all.. well until they are stupid enough to paste the holiday snaps of endless partying on their FB.

This is tip of the iceberg stuff Febo. Its racist and it kills. We in the west have far less culture than we could ever think.

Denying countries access to a compound that was readily effective and is now marginally so on ideological principle is environmental racism spelled with a capital irony.

After all, its these same wallies who take marginally effective perscription drugs (read any control trial) and yet stand on their heads about environmental compounds that have the same efficacy rates in other countries.

Henk van der Gaast, Sydney
November 28, 2010 2:30pm

"Denying countries access to a compound that was readily effective and is now marginally so on ideological principle is environmental racism spelled with a capital irony."

You aren't actually reading anything that anyone is saying here, are you?

One of the main points here is that No one is proposing denying anyone access to DDT, and Dunning even admits so at the end of his article. Yet he accuses various environmentalist groups of being racists, based on the notion that they do want to deny the use of DDT -- which they clearly don't.

You do see the utter hypocrisy there, don't you?

Febo, Manchester, UK
November 29, 2010 3:34am

Actually Febo, you arent reading what I am saying. Its an allowed thing on skeptoid.

I was talking about environmental racists that you spent many paragraphs rabbiting about in your previous posts.

Issues such as agriculture, mining, water management and fisheries are constantly being "addressed" by these groups but they don't kick head at home.

My point being, we use the countries that are dirt poor for more than economic reasons. We use them for exploitation be it riches, sexual or ideological.

There is this small place called Africa (its below Italy on the map) that gets right royally screwed by every idealog and criminal that wants to make a name for itself.

We, those outside Africa, made it that way.

Henk van der Gaast, Sydney
November 29, 2010 7:25am

Herst van der Gaast:

"My point being, we use the countries that are dirt poor for more than economic reasons. We use them for exploitation be it riches, sexual or ideological."

The fact that you're trying to change the subject away from malaria and DDT illustrates that even you realize you're in the wrong on this topic. (Febo has already pointed you to Deltoid and others on the substance if you need it. But my sense is you don't care.)

that you're trying to change the topic to the sexual e

Crust, New York
November 29, 2010 9:56am

no, the topic had gravitated to environmental racism.

we are all racist when it comes to the welfare of others.. I pointed out that environmentalists are probably the worst ideologues in that regard.

Folk dont really care if other folk are starving , disease ridden or exploited in other countries but as soon as an "environmental" issue comes up, you get the nobrainer set lobbying regimes.

Ive stated a number of times that Carsons book was out of date when published, DDT effectiveness was declining before Carson published. But DDT has other uses in vector control and possibly hot spot elimination.

As stated before, DDT has its uses. Ask the sub Continentals.

So let get down to tin tacks, what do you think will happen when GM has a great solution to either mosquito or forage control by larval or adult phases? Yet these self same environmentalists eat common foods that are GM modified without checking.

(on that point, I take great satisfaction watching the "nice" outlets flogging their ideological sound products).

Yep, there will be whale boats in central africa.

The problem is that the populist enviromental activists have a lot to lose if their little patch is eroded.

PS, get off Febo's High horse Krusty. The second you start saying that you wont recognise your part in the exploitation because its just too big, I will at least laud your honesty.

Is DDT as bad as Carson made out?

Henk van der Gaast, Sydney
November 29, 2010 5:15pm

"As stated before, DDT has its uses. Ask the sub Continentals."

You mean India? The country that uses four-fifths of the world's supply of DDT for malaria control, and still has one of the highest rates of Malaria?

wintermute, Cincinnati, Ohio
November 30, 2010 6:12am

<i>Folk dont really care if other folk are starving , disease ridden or exploited in other countries...</i>

You are speaking for yourself, I presume. You don't speak for me, nor do you accurately represent me.

I grant you that relatively prosperous white Westerners lobbying for indigenous rights, fair trade and fast technology transfer are considerably rarer than they ought to be, but you don't get to erase us from existance just because you aren't surrounded by us.

@Scott Field,
I did see Brian's statement about how he didn't use JunkScience, subsequent to that -- but, sorry, this seems deliberately disingenuous in light of the fact that he used a shedload of the exact same arguments and misrepresentations as Milloy/JunkScience have on their site. Strange coincidence, that, especially since it *was* in his list of references, and his initial response to criticisms at <i>November 02, 2010 10:30am</i> above wasn't anything at all like "I didn't use them." Frankly, I think it would be more respectable and respected for Brian simply to say "ok, I f***ed up on this one".

Lynne, Scotland
November 30, 2010 7:02am

Everyone does.

Marshall, Smyrna, GA
December 2, 2010 6:41am

Lynne, beaudy, from your mission in equatorial scotland feeding and educating the poor and meek i see...

Do you really care? do you at least vet your purchases to make absolutely sure you are not propping up some despotic regime or business?

Have you foresworn lifes little trinkets like television, mobile phones or PC's..

let me guess, you care but it has its limitations.

I wasn't holding myself up as a beacon of propriety, charitability or international bon-homie.

I pointed out that folk just dont care. If that offends you, don't bother telling me, move to non equatorial scotland to give them speech pathology.

Auld lang syne indeed.

PS, Fair trade is another issue Brian should skeptoid

Henk van der Gaast, Sydney
December 8, 2010 6:46pm

The KKK has nothing on the Left for making life difficult for poor, brown people.

Government Goodies, Government Lab
December 16, 2010 9:52am


Mr. Dunning seems to refuse to acknowledge and correct factual errors, insisting that those questioning his evidence and conclusions are politically-motivated in doing so...check it out and see if you don't agree.

Peter Rott, New York, NY
January 12, 2011 7:07am

I do insist that when it's the case. Lambert says himself that his blog is a political blog, and that DDT is one of his pet peeves.

The rest of the time I correct errors wherever they're found, both on the transcripts and in my "Things I'm Wrong About" episodes.

Brian Dunning, Laguna Niguel, CA
January 12, 2011 9:45am

It seems to me that Lambert repeatedly points out numerous FACTUAL errors, but gets no direct response. Other commenters make the same point, and again get no direct response. Because Lambert writes a political blog does not make his criticism necessarily political; using this justification to avoid admitting error strikes me as pretty weak tea, and is something I believe you would chide others for.

In any case, I invite all readers to check out the discussion at skepticblog and decide for themselves.

Peter Rott, New York, NY
January 12, 2011 11:45pm

No, but it may (and does seem to) have an impact on the sources selected and how he chooses to present them. Brian hasn't said he wont address the issues, just he wont do it on a ground with a political slant and would rather address the arguments in a "things im wrong about episode", which is a fair sentiment and more than many commentators are willing to give.

As to "no direct response" scroll up and read the episode again. It has been corrected and anotised. That seems pretty direct as a response. Somebody found a mistake so Brian added additional information such as the note on the WHO ban. What more can you ask for a responsible reaction? Other commentators are as welcome to their conclusions as Brian is to his, that somebody disagrees with him is no reason to expect the man to enter into arguments if he does not want to, only to show the evidence on which he based his conclusions.

Tom H, Kent, UK
January 13, 2011 4:10am

I do not say that my blog is a political blog. Again Dunning tries to avoid making corrections by attacking his critics.

Tim Lambert, Sydney
January 19, 2011 6:59am

now this is totally off topic but please bear with me i was just watching on TV how expensive certain
medicines are
and how people are complaining
how expensive they are because it only cost 2 cents to make the pill well the second pill cost 2 cents to first pill cost a couple of 100 million now i was thinking why now have a govt buy the pill patent yes it would cost a lot but u could also whack down the price i know this doesn't fit into the ep but the closes thing i could find if u know of some where more suitable please tell me or move it there :)

alfred, chch nz
January 22, 2011 10:46pm

1) Alfred...SON!

2) Your Blog is a Blog. Why should Brian (yes he has a first name) use your blog as a basis of argument? Should you use my blog as a criicism of you, even if I dont know you from Adam or had read your blog.

3) whilst i detest coming out of my enforced slavery (renovations) and risking the ire of Fox moderator, I have to point out that Brian is wrong and right. whilst criticism of his blog/whatever is way of beam.

Brian is right in stating that DDT is an effective insecicide and its use should have proliferated a bit longer than it should have. Where Brian should have researched is that biological resitance to the toxin is now becoming reduced (but its been inferred, correctly, that program use was avoided in certain areas.

DDT is cheap and moderately effective. Its far more effective than ridiculous "organic" toxins. Technology is way ahead of DDT and "nature boys" insecticides. Science is 20 years ahead of technology in that regard.

So, If anyone is going to blog on the lack of value of DDT verus current insectides on economic, environmental and practicality grounds, they had better be up to date on modern technology, scale and distribution potential of modern synthetic insect neurotoxins.

After all, if australia is to target native insects using prime atraxatoxins (the most very organic insecticide) it had better be made in petrochemical tanks.

I apologise if I have missed any valid criticism of my generous benefactor and religious Mod.

Henk van der Gaast, Sydney, Australia
January 23, 2011 8:03am

i think it sucks theres little info on everything

rhiana curry, charlotte,north carolina
February 8, 2011 6:56am

@Tom H: I was referring to the discussion at skepticblog, where Brian was certainly participating, and, as I saw it, playing the "political" card to avoid answering factual objections.

He states here that, "With that said, corrections will be made to erroneous assertions in this episode in a future Things I'm Wrong About episode, and are noted in the transcript above. The errors that have been pointed out to me so far are not, in my opinion, significant enough to alter my conclusions." If you check out the link, you'll see that there are many more objections than the two Brian acknowledges (or are corrected in the body of the original podcast). If he wishes not to debate them there, and not to debate them here, then where? And if he's unwilling to defend them...

Brian also says, "Skeptoid is not here to tell you what to think." If you take a look at many of his other articles, he is rather willing to tell you what to think...or at least to call something BS when it is (instead of presenting it neutrally and letting the reader decide). And we applaud him for that. But when his readers point out that he has used crap information about DDT to "balance" what is presented by scientists, people are going to start scratching their heads.

I'm not sufficiently tempted to summarize the discussion, but again, if you're interested:


Peter Rott, New York, NY
February 19, 2011 11:08pm

There is a difference between telling you what he considers Bull and why, and telling you to think it is Bull. The DDT episode is no different, he put his opinion out there and some people disagreed. Calling the thred an "epic fail" is pretty much making a point with no sense of balance or objective scrutiny. It is starting form the view "He is wrong". So it does seem a little unfair to accuse Mr Dunning of the same issue. He is under no obligation to explain his opinion on any forum he does not want to use.

It is of course an entirely different issue to the subject of the podcast, but it is a rather pragmatic point that should be considered: If the podcasts are self edited, free, podcast that offers one mans opinion, and he has shown all the evidence on which he has built that opinion so others can make up their own mind, why exactly should be obliged to answer questions in a discussion whose motivation is to describe him as a "fail" (that would be a political stance) rather than to discuss if a different opinioin would have been reached based on other evidence he may or may not have encountered in his research?

Tom H, Kent, UK
February 20, 2011 6:12am

If only pesticides (like nuclear reactors) were used properly:

I worked as off-sider to a former panzer driver who was a pest controller on a military base. Called in to eradicate a massive wasps nest on the side of a hill, he filled a bucket with kerosine and added a full can of DDT. This he poured into the hole in the hill containing the wasps nest

He was just about to throw the match in when the military police drove up to ask what we were doing. I said "Ask him" and pointed at my mate.

They told us to get in the vehicle and took us round the front of the hill and then drove a little way inside a large door

Yes - it was the main ammunition dump.

"Learnt anything?" the MPs said

"Yes" I said, "I'll get him to read the label on the can next time."

Phi, Sydney
March 23, 2011 5:36pm

So Phi, any proof nuclear reactors arent used properly? Or that most farmers don't work with in pretty tight regulations? Or is this another case of the assumption your experience is indicative of the entire world?

Lets look at my experience and compare and contrast shall we; anybody who makes that kind of mistake finds themselves under an investigation for not completing a proper COSHH assesment, and probably investigated by either the HSE or the Environment agency.

Being in a good union helps, because their employer is likely to consider them a liability. That is when subcontractors find themselves with out a contract.

I have no doubt, (and good evidence…) people misuse pesticides. But that is why we have control measures and we enforce them. For actual evidence look up the coshh control sheets for pesticides.

Illuminatus, fantasy island
April 26, 2011 11:25am

Phi may be saying that nucear reactors cant be updated because of the antitechnological fringe whipping up an anti nuclear vote on reactor replacement. There are perfectly safe reactor designs and frankly, the nuclear industry is as safe as you can get.

When the public weighs an apparent scary word like nuclear against a non scary phrase like general industry they think of weapons.

Phi, in what moorcockian universe was this tale elaborated? Can you lose this periodical reference to former ss/wehrmacht?

We have to face facts, we have in the past had a little too much zeal in a lot of things. Biologically, I see DDT as about as bad a threat in our day to day chemical exposure. If some snippet says DDT is bad, I am sure another sector will say, forget DDT, floor polish kills..and maybe rightly so..But on average we live longer and more fruitfully than ever before.

The thing is overwhelming claims about a compound need overwhelming evidence. Its easy to aggrandise small and most likely non synergistic properties to demonise one thing we think we dont like in favor of something else.

DDT is essentially outré in our society and we have better compounds that are cheap for us to disseminate. I agree with Brian, the evidence seems to be mainly outcry and exampling of properties, exaggeration of claims. Its cheap and effective when used correctly (sans matchbox).

Should old nuclear reactors be replaced? Has anyone a better cheaper and safer technology? Not lately!

Henk v, sin city NSW, Oz
August 9, 2011 11:25am

DDT is more dansers for us through our crop's production.DDT is dichlorodiphenyltrichloroethane. It's a completely synthetic compound that does not exist in nature. It's a white, powdery, waxy substance that's hydrophobic: It doesn't dissolve in water and so does not contaminate it, but readily dissolves in solvents and oils. It's applied as a white smokey mist. DDT kills insects by chemically enhancing the electrical connections between their neurons, short-circuiting them into spasms and death. DDT's hydrophobic nature is both a blessing and a curse. It can't contaminate water sources, which is good; but it also doesn't get dissolved away by them and diluted into virtual nothingness, so it hangs around for a long time.it would be completely wrong to overlook DDT's potential for causing harm simply because there are other things that cause harm toosobe awaoid this insfctcide

ibrahim, nangloi
December 3, 2011 11:15pm

I was at Club Med in Moorea, Tahiti in '93 and they used DDT every night just before dusk and I never got a mosquito bite the whole time. The applicator guy drove around in a golf cart with a fogger on the back, kind of reminded me of Tattoo on Fantasy Island...

Glen, Vancouver
March 21, 2012 7:20pm

Brian - for another perspective on why DDT use declined in other countries you should read "The Merchants of Doubt".

Jamie, Gilston, Australia
October 2, 2012 3:20pm

well this is good but yeah ...

Prank Sayers, Warren New South Wales
November 12, 2012 7:26pm

What about the return of bed bugs? Maybe you can cover that topic.

macsnafu, Tulsa, Oklahoma
January 25, 2013 2:01pm

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