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September 23, 2007

You Down With DDT? Oh No, Not Me

By Neil the Ethical Werewolf

Aaron Swartz has a nice article about how chemical companies looking to sell their product and conservatives who want to smear environmentalists have been spreading the myth that banning DDT caused millions of deaths from malaria.  As it turns out, the reason that people stopped using DDT a lot in poor countries wasn't because of Rachel Carson's baneful influence -- it was because mosquitos started becoming DDT-resistant:

DDT use has decreased enormously, but not because of a ban. The real reason is simple, although not one conservatives are particularly fond of: evolution. Mosquito populations rapidly develop resistance to DDT, creating enzymes to detoxify it, modifying their nervous systems to avoid its effects, and avoiding areas where DDT is sprayed — and recent research finds that that resistance continues to spread even after DDT spraying has stopped, lowering the effectiveness not only of DDT but also other pesticides.

An article from Current Biology describes how flies with DDT resistance not only become able to resist other insecticides, but also gain unexpected super powers:

Mutations that confer pesticide resistance are predicted to carry a cost in the absence of pesticide and consequently not to spread to fixation [1 and 2]. However, DDT resistance in Drosophila melanogaster (DDT-R) is approaching fixation globally, long after withdrawl of DDT [3]. There are two possible explanations for this. First, other insecticides, to which DDT-R confers cross-resistance [4], may be continuing selection. Second, DDT-R may not carry the expected fitness cost. Here we look at the fitness of DDT-R in the absence of insecticide. Surprisingly, when inherited via the female, the DDT-R locus actually increases both adult fecundity and the viability of eggs and larvae, as well as speeding both larval and pupal development.

I'm guessing that flies were used in that experiment because they're easier to study in the lab, and I don't know how well the results carry over to their blood-sucking brethren.  But if DDT resistance has the same effects in mosquitoes as flies, we can see very good reasons not to use it anymore.  What doesn't kill every last mosquito only makes them stronger. 

So what do we do about malaria?  Our best bet, it appears, is artemisinin.  It doesn't kill mosquitos -- it's a drug that kills off the malaria parasite once it gets into the human body.  It costs between $1 and $2.50 per dose.  There's also the old-fashioned but apparently effective solution -- mosquito nets treated with insecticide.  Either way, we'll have to spend a lot of money if we're going to eradicate the disease that may have killed more humans than anything else.  (Apparently Bill Gates is opening his wallet, and surprising partnerships between pharmaceutical companies and relief groups are being formed.)

And what do we do about right-wing think tanks, funded by oil companies and other groups with an interest in discrediting environmentalists, who set up pro-DDT web sites?  I don't know. 

September 23, 2007 | Permalink

Comments

If it's fruit flies used in the experiment, they are used because they have short life cycles. Since evolution happens over a number of life cycles, it makes sense you'd want to speed the process up for the human observer.

Conservatives love DDT though. It can still be a useful pesticide sometimes in someplaces, but conservatives want people to eat it on their cornflakes.

Posted by: stm177 | Sep 23, 2007 8:23:47 AM

Do you have actual epidemiological data which shows DDT resistance is a widespread problem in Africa?

Or do you have anecdotal reports that some mosquitos in lab controlled conditions become resistant?

YOu do know there's a huge difference in the validity of those studies, right? One of them should be used for making public policy decisions regarding DDT, and the other should not. I'll let you guess which one.

Posted by: joe blow | Sep 23, 2007 9:24:22 AM

This is fucking hilarious.

Trying to change the American, or any other, public's opinion on DDT is a waste of time and money. They may as well try and convince people that child molestation is a good thing. It's just not going to happen.

Posted by: soullite | Sep 23, 2007 9:29:51 AM

Or do you have anecdotal reports that some mosquitos in lab controlled conditions become resistant?

That's funny. That's really funny. I hope that everyone is able to understand that "lab controlled conditions" is just a poor attempt to denigrate scientific research, which is of course the opposite of an anecdote.

I'd be willing to be very large sums that you've never given a moment's thought to the problem of malaria, that you don't give one little damn about DDT or any of this. You just can't stand it when your political opponents are right, and are willing to spew endless amounts of bullshit in your quest to deny reality.

Posted by: Stephen | Sep 23, 2007 9:33:21 AM

Stephen, I think everyone here who read Joe Blow's statement assumes he's a paid industry shill. Even his chosen moniker reeks of a false populism that's just laughable.

Posted by: soullite | Sep 23, 2007 9:57:46 AM

I think everyone here who read Joe Blow's statement assumes he's a paid industry shill.

The sad thing about the right wing commentariat, from blog commenters to the Instapundit himself, is that they're unpaid shills of the industry. They've actually come to believe the idiocy that corporations used to have to pay people to spout.

Posted by: DivGuy | Sep 23, 2007 10:31:16 AM

The go-to place to learn about DDT's industry shills is Tim Lambert's Deltoid. For example, an older post on DDT-resistance in Africa is here.

Posted by: dbomp | Sep 23, 2007 10:32:33 AM

Yeah, I agree with DivGuy - I figured he was an unpaid conservative shill doing his shilling as a hobby. Why pay for the cow when you can get the milk for free, after all?

Posted by: NonyNony | Sep 23, 2007 1:27:30 PM

My understanding is that there's plenty of evidence that mosquitoes have become resistant to DDT. I've heard this many times before; it's old news. (The commenter above is correct about why fruit flies get used in experiments.) Environmentalists need to partner with Bill Gates, point out that his low-tech, low-expense, low-environmental impact approach works, and thus there's no reason to do anything else that's more expensive or risky.

Posted by: beckya57 | Sep 23, 2007 2:16:14 PM

Well ... now we know why the right is so against teaching evolution -- the people who make insecticides don't want people to realize that widespread use of DDT will select for DDT resistant bugs rendering DDT usage pointless anyway. ( / tinfoil hat wearing ).

Seriously, though: isn't it self-evident nowadays given what we know of evolution of resistance, that the kind of DDT usage for which the right and the industry shills seem to long is not something that could keep the bugs getting killed for long?

Admittedly the generation time for insects is a lot longer than for bacteria, but we do know how well antibiotic over-use has worked out, don't we? Even in the 1950s, resistance was a problem with bacteria (two of my uncles died in infancy due to antibiotic resistant infections) ... so why should it be a shock that DDT resistance would be a problem? Why do people act as if "if it weren't for those dirty f$%#ing hippies, we'd still be able to kill a bunch of mosquitos for ever and ever with DDT"? For that matter, why do they say the same thing about the Iraq war vis-a-vis us dirty hippies?

You'd think that today's so-called conservative movement simply has watched too many Scooby-Doo cartoons and identifies themselves with the villains and us with Scooby, Shaggy and the gang.

Posted by: DAS | Sep 23, 2007 2:33:32 PM

The sad thing about the right wing commentariat, from blog commenters to the Instapundit himself, is that they're unpaid shills of the industry.

That's the depressing thing about "selling out." You realize that even if you wanted to sell out, you couldn't get much wealth from doing so because so many other people are willing to do it for free.

Seriously, "lab controlled conditions"? The alternative is "uncontrolled" conditions, which joe blow would then claim can't produce good results because the conditions were not properly controlled.

Hey, I think I found my new job-- not repeating talking points (which people will do for free), but writing talking points! Anyone want to hire me?

Posted by: Tyro | Sep 23, 2007 3:55:26 PM

I'm still waiting for the studies guys. You're the "experts" right so it shouldnt take you so long to come up with the proper data.

As for the comment about "lab controlled" studies:

"Lab controlled" data show that water causes cancer in mice. "Lab controlled" data show that cell phones cause brain tumors in rats. Now I want a show of hands as to how many of you are throwing away your cell phones and swearing off water. Yeah, thats what I thought.

I'm keeping an open mind about this. If there is strong epidemiological data showing that mosquito resistance to DDT is a major widespread phenomenon in Africa, then absolutely lets rethink our use of DDT. But citing anonymous lab studies without further analysis to dictate public policy on a disease that kills millions of people per year is not good science.

Posted by: joe blow | Sep 23, 2007 4:19:25 PM

Seriously, "lab controlled conditions"? The alternative is "uncontrolled" conditions"

Nice straw man you fucking idiot. Obviously you are unaware of the nuances of scientific research.

Here's an example for your simpleton mind:

Experiment #1: Cervical transitional epithelial cell lines are cultured in vitro and exposed to HPV. Half the group is given Gardasil, half is not. The gardasil half shows reduction in HPV viral titers after 3 weeks, the control group shows no difference.

Experiment #2: 50,000 American women aged 7 to 35 are divided into 2 groups. Cervical sampels from both groups are taken for baseline PCR viral loads of HPV and found to be nonsignificant. Baseline pap smears for detection of cervical cancer are nonsignificant. Half hte group is given Gardasil, the other group gets placebo. These women are followed for the next 40 years and screened yearly for cervical cancer.

Now you tell me which experiment is the real deal and which one sounds promising but needs further research before using it to make public policy decisions.

Posted by: joe blow | Sep 23, 2007 4:31:00 PM

joe blow, let's face the facts-- if there were some other kind of experiment showing the same thing about DDT, perhaps out "in the field," you'd complain about that, too. You're not here to say anything valid, you're here to push the talking points.

Seriously, it's such a joke that a bunch of right-wingers who, never before having any interest in science and whose biggest concern was making sure we were "kicking ass" in iraq, cutting taxes for rich people, and making sure "welfare queens" weren't using their tax dollars to buy cadillacs, have suddenly taken an interest in DDT and Public Health issues in Africa. Spare us. You're reading off a script, and your concern doesn't extend any further than the talking points fax that told you to throw a fit over it.

Posted by: Tyro | Sep 23, 2007 5:09:20 PM

DDT is at one of the weird confluences of the sewers of the rightwing mind. They love to think that there is a magic powder that can be sprayed indiscriminately, killing everything, and thus creating the kind of world they like. It drives them absolutely nuts to think that a songbird could be more important than a parking lot. And, being totally incapable of curbing their racism at home, they hope to overcompensate by demonstrating (verbally only, of course) how concerned they are about the poor foreigners. They still believe in the "white man's burden".

Thank god the American Century is over.

Posted by: serial catowner | Sep 23, 2007 5:25:37 PM

I'm a novice in this area though I have some interest in malaria from work on the history of slavery. But I have some questions:

Swarts seems to assume that the buildup of resistance in drosophila is a proxy for similar processes in mosquitos. I see plenty of mosquito studies in the J Tropical Disease and Hygiene that refer to drsophila experiments, but I'm not knowledgeable enough to say whether they're making the same assumption. Is ia an appropriate one to make?

As I checked around on this much-debated topic, I came across reports (e.g. in Science mag) about Arata Kochi the new (2006) head of the World Health Organization from which Swarts' source, Allan Schapira, resigned. Kochi too claims to be opposing Big Pharma, but his concern is not the companies that make DDT but those that make artemesinin. Swarts could have told us more about this. Unless its just a scam, it make the dispute less one of white hats vs black hats, but a more complex matter.

Dan Tompkins

Posted by: Dan Tompkins | Sep 23, 2007 5:33:25 PM

Dan Tompkins, could you explain your last post a little more? I read it three times, and I still don't understand what you are getting at. Thanks.

Posted by: stm177 | Sep 23, 2007 5:58:46 PM

DDT works by opening sodium pathways in the mosquito's nervous system, causing random firings of neurons, killing it. it doesn't take many generations for mosquitoes to evolve countermeasures to that kind of attack, since it's merely a passive chemical reaction.

and here's a study of mosquito resistance in the wild that took all of 10 seconds to find. if i'd wanted to, i'm sure i could produce a hefty list that joe blow would still object to.

Posted by: Cody | Sep 23, 2007 6:21:37 PM

Okay, okay. There's always the possibility that Joe Blow is just an idiotic ditto head. But I still think it's fairly likely that he's being paid by someone to talk this shit. I don't know why people throw their money away on bullshit like that, but they do. It's not like he's going to be convincing a whole lot of people here.

Posted by: soullite | Sep 23, 2007 7:33:53 PM

I think that the pesticide that should be used to treat mosquito nets is DDT. Ezra mentioned the reason -- mosquitoes avoid DDT so it doesn't have to kill them to keep them away http://tinyurl.com/ysfcfn. This reduces the selection problem.

I note that the WHO supports the use of DDT *indoors* http://tinyurl.com/2hqj7n. The point is to refrain from spraying it everywhere so the mosquitoes can't avoid it and ddt resistant mosquitoes are selected [and raptors are driven extinct]

Posted by: Robert Waldmann | Sep 23, 2007 8:52:03 PM

One more thing; the use of DDT was never banned in Africa! It's widespread use was reduced significantly when the WHO made strong recommendations not to spray it all over the place.

The other thing about DDT is its persistence. I degrades VERY SLOWLY in the environment. Once ingested, it is sequestered in fat tissue and as best as is known stays for the lifespan of the individual. It also has very weird effects on the sex steroid system. Here's an article about the effects of DDT on singing behavior in wild robins:

http://www.livescience.com/animals/060721_robin_brains.html

It's amazing that the right wing lives in this bizarre alternate universe where DDT tastes great on morning cereal and pretty pink ponies ride free across the sands of Iraq...

Posted by: CKT | Sep 23, 2007 11:57:35 PM

DDT isn't a good choice for treating nets. Its main advantage is that it's cheap to make, but it is much less potent than synthetic pyrethroids. If you are spraying it on walls you can compensate for this by putting more on the walls, but nets can't hold that much insecticide. The big advance in this area is long-lasting insectide treated nets. They last for five years instead of having to be retreated every year.

Posted by: Tim Lambert | Sep 24, 2007 5:40:58 AM

Based on my experience, the most effective strategy to fight malaria is a combination of elements:
DDT spraying
insecticide treated mosquito nets
artemisinin-based combination therapies.

This is the strategy currently being implemented in East Africa with the result being a significant decrease in the total numbers of infections and loss of life.

The Clinton Foundation is also making a significant contribution to the fight against malaria. Their strategy is to replicate their successes from the HIV Aids sector in the malaria sector. The recently launched a pilot project in Tanzania to dramatically reduce the cost of artemisinin-based combination therapies in the private sector. I have a lot of confidence in their strategy and look forward to their increased participation.

Posted by: Lisa Amenya | Sep 25, 2007 2:11:31 AM

Based on my experience, the most effective strategy to fight malaria is a combination of elements:
1) DDT spraying
2) insecticide treated mosquito nets
3) artemisinin-based combination therapies.

This is the strategy currently being implemented in East Africa with the result being a significant decrease in the total numbers of infections and loss of life.

The Clinton Foundation is also making a significant contribution to the fight against malaria. Their strategy is to replicate their successes from the HIV Aids sector in the malaria sector. They recently launched a pilot project in Tanzania to dramatically reduce the cost of artemisinin-based combination therapies in the private sector. I have a lot of confidence in their strategy and look forward to their increased participation.

My way of thinking is that we are unable to eradicate malaria using only one approach. Through public and private interventions, spraying, nets and drugs...we may have a chance.

Posted by: Lisa Amenya | Sep 25, 2007 2:13:03 AM

You can find part of the origin of the malaria garbage at Exxon's annual reports from several years running when they gave money to a South Africa organization that has malaria in their name. It kind of stands out because it is one of their only foreign donations. Then Milloy's site Junk Science has a rant about Malaria deaths that appears to be where Chrichton got his bad numbers on child deaths. Milloy was one of Exxon's contractors for several years and you can find him on the list of contractors paid on their tax return. He was working with CEI manufacturing tobacco doubt prior to that (I think.) I just wonder what financial interest Exxon has in DDT production. Don't forget that the synthesis of DDT creates an equal amount ot DDE which is an estrogen mimic. It's the reason the alligators in Lake Apopka are all girls.
The argument goes "Nobody ever proved that DDT causes cancer." It's true but with the evidence pointing in that direction and several good substitutes in the works, we started using other insecticides. The other part of the argument says that the US withholds foreign aid from countries that use DDT. It denies the existence of the WHO completely. This is a typically anglo-centric attitude that ignores the competence of foreigners. Take for instance the 1500 peer-reviewed articles on global warming reviewed by the IPCC committee by scientists from around the world. You find that the skeptics only pay attention to the US work and ignore the rest of the world except to mention the vague world-wide conspiracy of companies that will "benefit from global warning." That would include the cabal of seawall contractors - lol. Also the evil air conditioning contractors.

A friend of mine repeated it one too many times so I told him I would buy dinner if he found a verifiable instance that wasn't about everybody on earth taking advantage of making new stuff like solar panels. It has been a month and I haven't bought dinner yet. I'll have to do it anyway as a sort of going away present to Rush Limbaugh's influence.

Posted by: Bob Calder | Sep 25, 2007 9:38:09 PM

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