Subtitle: My small attempt to educate Instapundit about DDT use and malaria

Rachel Carson famously wrote the most influential book in the history of the environmental movement. It was called Silent Spring and it cataloged all the terrible consequences to other species and ourselves resulting from the use of the chemicals we used to kill off insects, pests and weeds.

Glenn Reynolds of Instapundit today cited this bit of malarkey regarding Rachel Carson’s responsibility for millions of deaths caused by Malaria because DDT was banned.

FORBES’ RICH KARLGAARD ASKS how many people died because of Rachel Carson?

Buried in paragraph 27, and paraphrasing the Congressman, The Washington Post concedes that “numerous” deaths might have been prevented by DDT.

Let’s stop here. Any curious reader would ask, Just how “numerous” is numerous? Wouldn’t you ask that question? The Post never asks that question. Why?

Because the answer devastates Rachel Carson and her followers. According to these CDC figures, malaria kills more than 800,000 children under age five every year.

Every year, 800,000 small children die from malaria, a disease once nearly eradicated. Ponder that.

And all The Washington Post can say is “numerous?”

That’s scandalous.

More on that subject here. It’s certainly an argument against overreacting.

So, are KARLGAARD and REYNOLDS right? Did Rachel Carson cause more deaths because DDT was banned than Hitler killed Jews in the Holocaust? Is she, good intentions aside, the one person primarily responsible for the deaths of millions because she got DDT banned?

Not exactly …

You see, DDT was never banned for use as an anti-malarial pesticide, only for mass use for agricultural purposes, although eventually many countries stopped using DDT as an anti-malarial pesticide. And with good reason, too. By the 1960’s many mosquitoes (and other insects) had already developed a genetic resistance to DDT which made it much less efficient as a pesticide that could actually prevent malarial outbreaks.

So, in the interest of fair play, I emailed the following information to Glenn Reynolds in the hope, faint that it may be, that he will retract this nonsense and stop smearing the good name of Rachel Carson. Here’s the text of my three emails (unedited except for some minor typo corrections, the use of html code to shorten links and the removal of my full name):


First email:

Dear Mr. Reynolds,

Never having been a law professor, but having been a lawyer, I was taught that one should know one’s facts before making an argument. Perhaps you were unaware, but the “facts” you quoted about Rachel Carson in your cite to Mr. Rich Karlgaard’s article were deeply misleading. Ms. Carson advocated the ban on DDT for use on agricultural products, not for use to prevent malaria, and indeed DDT is still in use as an anti-malarial pesticide in Africa and elsewhere. (link) )

Here is what Rachel Carson actually had to say about the overuse of DDT to kill agricultural pests and thus spread resistance to DDT, making disease outbreaks harder to control:

LINK:

No responsible person contends that insect-borne disease should be ignored. The question that has now urgently presented itself is whether it is either wise or responsible to attack the problem by methods that are rapidly making it worse. The world has heard much of the triumphant war against disease through the control of insect vectors of infection, but it has heard little of the other side of the story – the defeats, the short-lived triumphs that now strongly support the alarming view that the insect enemy has been made actually stronger by our efforts. Even worse, we may have destroyed our very means of fighting. …

What is the measure of this setback? The list of resistant species now includes practically all of the insect groups of medical importance. … Malaria programmes are threatened by resistance among mosquitoes. …

Practical advice should be ‘Spray as little as you possibly can’ rather than ‘Spray to the limit of your capacity’ …, Pressure on the pest population should always be as slight as possible.

Please make the correction on your blog. Rachel Carson isn’t responsible for the deaths of millions, and you should not be spreading the misinformation of people like Karlgaard regarding her impact on human health and/or the spread of diseases like malaria. On the contrary, her contributions to the health of our planet and the human beings who live on it have been entirely salutary. Propagating the false myth that she was some sort of environmentalist Eichman is beneath you.

Yours truly,

Steven xxxxxx

Second email:

Dear Mr. Reynolds,

As futher support for my prior email to you on the subject of Rachel Carson and DDT, here are the remarks of two Australian parisitologists in a letter to the editor posted in The Australian on Feb. 2, 2004 regarding the alleged “ban of DDT use” (alleged but not true):

…The manufacture and use of DDT was banned in the US in 1972, on the advice of the US Environmental Protection Agency. The use of DDT has since been banned in most other developed nations, but it is not banned for public health use in most areas of the world where malaria is endemic. Indeed, DDT was recently exempted from a proposed worldwide ban on organophosphate chemicals.

DDT usage for malaria control involves spraying the walls and backs of furniture, so as to kill and repel adult mosquitoes that may carry the malaria parasite. Other chemicals are available for this purpose, but DDT is cheap and persistent and is often a very effective indoor insecticide which is still used in many parts of the world.

DDT is not used for outdoor mosquito control, partly because scientific studies have demonstrated toxicity to wildlife, but mainly because its persistence in the environment rapidly leads to the development of resistance to the insecticide in mosquito populations. There are now much more effective and acceptable insecticides, such as Bacillus thuringiensis, to kill larval mosquitoes outdoors.

Reductions in the use of DDT did occur in a number of developing nations after the US ban in 1972. This reflected concerns over environmental consequences of DDT, but was also a result of many other factors. One of the important factors in declining use of DDT was decreasing effectiveness and greater costs because of the development of resistance in mosquitoes. Resistance was largely caused by the indiscriminate, widespread use of DDT to control agricultural pests in the tropics. This problem, in fact, was anticipated by Carson: “No responsible person contends that insect-borne disease should be ignored . . . The question that has now urgently presented itself is whether it is wise or responsible to attack the problem by methods that are rapidly making it worse.”

Malaria is a major, ongoing disease problem in much of the developing world. Increases in the incidence of the disease have occurred for complex reasons. Reduced insecticide usage is one, but others include the resistance to treatment in both the parasite and the mosquito vectors, changes in land use that have provided new mosquito habitat, and the movement of people into new, high-risk areas.

Most nations where malaria is a problem, and most health professionals working in the field of malaria control, support the targeted use of DDT, as part of the tool kit for malaria control. Most also agree that more cost-effective, less environmentally persistent alternatives are needed. There are some effective alternative chemicals for the control of adult mosquitoes, but preventing their further development is lack of invest ment by industry, because malaria is largely a disease of the poor.

Malaria is responsible for enormous suffering and death. The facts are readily available in the scientific literature. To blame a reduction in DDT usage for the death of 10-30 million people from malaria is not just simple-minded, it is demonstrably wrong. To blame a mythical, monolithic entity called the environmental lobby for the total reduction in DDT usage is not just paranoid, it is also demonstrably wrong. Your article is not only poor journalism, it is an insult to the people who work for the control of parasitic diseases that afflict developing nations.

Dr Alan Lymbery
Professor Andrew Thompson
Parasitology Unit
Division of Health Sciences
Murdoch University

Perhaps you could post the text of this letter as a necessary corrective to the misinformation by Mr. Karlgaard. At the very least you should provide a link to this site (link) where your readers can make up their own minds on who is telling the truth about DDT use around the world.

Yours truly,

Steven xxxx

And my Third email:

Dear Mr. Reynolds:

Some further links regarding DDT

DDT as an endocrine disruptor: link

* * *

Study on DDT resistance: http://www.mrcindia.org/MRC_profile/vector_biology/insecti_resi.pdf

* * *

Genetic advantages of DDT resistance in insects: (excerpt follows)

Insects that can withstand the powerful pesticide DDT that was banned in the 1970s have a genetic advantage over their rivals that has helped them spread across the globe ever since, according to research published in Current Biology tomorrow (9 August 2005).

This discovery overturns current theories that resistance to pesticides burdens insects with a genetic disadvantage that would stop them from competing with non-resistant insects once farmers stop using that pesticide. […]

“These results are important for the use of any drug, pesticide or antibiotic as they suggest that resistance will not always go away when we do not spray or prescribe antibiotics.”

Scientists had previously believed that the genetic ‘cost’ of resistance would mean that DDT resistance would dwindle once the pesticide taken out of use and DDT-susceptible insects would regain dominance.

“Although this assumption is widespread, data to support this contention is actually thin,” said Professor ffrench-Constant. He believes previous work may not have looked at genetically related strains and that ‘costs’ may therefore be associated with the differing genetic backgrounds of insects examined, and not the resistance genes themselves.

* * *

DDT and Malaria (WaPo article): (excerpt follows)

But some DDT advocates have resorted to anti-environmentalist drama to make their case for its use in Africa.

They have accused environmental activists of having “blood on their hands” and causing more than 50 million “needless deaths” by enforcing DDT bans in developing nations. In his best-selling anti-environmentalist novel “State of Fear,” Michael Crichton writes that a ban on using DDT to control malaria “has killed more people than Hitler.”

Such statements make good copy, but in reality, chemicals do not wear white hats or black hats, and scientists know that there really are no miracles. […]

What people aren’t remembering about the history of DDT is that, in many places, it failed to eradicate malaria not because of environmentalist restrictions on its use but because it simply stopped working. Insects have a phenomenal capacity to adapt to new poisons; anything that kills a large proportion of a population ends up changing the insects’ genetic composition so as to favor those few individuals that manage to survive due to random mutation. In the continued presence of the insecticide, susceptible populations can be rapidly replaced by resistant ones. Though widespread use of DDT didn’t begin until WWII, there were resistant houseflies in Europe by 1947, and by 1949, DDT-resistant mosquitoes were documented on two continents.

By 1972, when the U.S. DDT ban went into effect, 19 species of mosquitoes capable of transmitting malaria, including some in Africa, were resistant to DDT. Genes for DDT resistance can persist in populations for decades. […]

In fact, pockets of resistance to DDT in some mosquito species in Africa are already well documented. There are strains of mosquitoes that can metabolize DDT into harmless byproducts and mosquitoes whose nervous systems are immune to DDT. There are even mosquitoes who avoid the toxic effects of DDT by resting between meals not on the interior walls of houses, where chemicals are sprayed, but on the exterior walls, where they don’t encounter the chemical at all. […]

In 2000, I chaired a National Research Council committee that published a study titled “The Future Role of Pesticides in U.S. Agriculture.” Our principal recommendation is germane to discussions of malaria management: “There is no justification for completely abandoning chemicals per se as components in the defensive toolbox used for managing pests. The committee recommends maintaining a diversity of tools for maximizing flexibility, precision, and stability of pest management.” […]

May Berenbaum is head of the department of entomology at the University of Illinois, Urbana-Champaign.

* * *

I hope you find some of the preceding informative. I know I did.

Yours truly,

Steven xxxxx

I haven’t heard back from the Ol’ Perfesser yet about his confusion on the subject of Rachel Carson, DDT and malaria, but if I do I’ll be sure to let you know what he had to say to me.

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