Friday, October 28, 2005

RIGHT FOR THE WRONG REASONS:

WHY THE DDT BAN SHOULD BE MAINTAINED

Once upon a time, a lady named Rachel wrote a scary story in which all the birds were poisoned by an evil chemical. People awoke one day to a Silent Spring.

Pretty birds... All gone.

Let's keep one thing foremost in mind. Silent Spring was a story, not a study. It wasn't a report on scientific research. It wasn't peer reviewed. It was based on a relatively small body of field research which suffered from the defects almost always found in field research, namely, the lack of controls, an excess of variables, and no "zero" point.

Ultimately, the work was found to be inconclusive. Interpretations of this abound, coming from both sides of the debate.

It didn't matter in 1972. In 1972, the environment was on the ropes and people were worried. Worried, and predisposed to believe scary stories. Largely due to political pressure, DDT was banned in 1972.

DDT has been around a long time. It's cheap and easy to make. It is devastatingly effective at killing insects. It is basically nerve gas for bugs, affecting them much the way Sarin affects people. It is almost entirely harmless, at least in the short term, to people.

The ban was a great symbolic victory for the environmental movement the pave paradise lobby has never forgotten. Repeal of the ban has been pushed in Congress many times and is being pushed again.

Enter Steven Milloy, The biostatistician who is FoxNews' resident Junk Scientist. Insisting "DDT Is Only Real Weapon to Combat Malaria"

http://www.foxnews.com/story/0,2933,173766,00.html

Mr. Milloy drags out his Rachel strawgirl and trots through all the "facts" - or at least the "facts" circa 1972 - makes a few unprovable blanket statements, and presents the "pro" case.

He notes, as do I, "DDT was ultimately banned in the U.S. in 1972 because of politics, not science."

Here's why he's just plain wrong: DDT kills bugs.

I hear the groans. Pretty birds... Ugly, bitey bugs. Few of us really like bugs, and few study them. Because of that, few people realize how drop dead vital they are to all life. Broadly speaking, the terrestrial landscape is a place dominated by trees and bugs.

That's not a story. It's a sober fact.

Experience using pesticides has taught us is that broad-range pesticides create something Entomologists call the infestation cycle. It starts with that unseen dominance of insects. Insects are the greatest plant eaters, and other insects are the greatest eaters of insects.

It's a bug eat bug world out there.

Enter DDT. Let's say, for example, you use it to stop malarial mosquitos. It'll kill maybe 99% of them, as well as 99% of all the rest of the bugs. Some survive by chance, some by natural resistance. But nature will not tolerate a vacuum, and the food is still there. Back come the bugs.

Nuke 'em again. Spray that poison. They come back. But not in the same proportions. Species that formerly were held in check by their fellow bugs by random chance establish populations without predators.

Start to use DDT, you can't stop. If you do, you get what happened in the Eastern US with the Gypsy Moth: Population explosions.

But if you don't stop, eventually resistant populations emerge.

So you stop, and it's years at best before things are back in balance. Years full of those population explosions.

This isn't an earth-worshipping "bugs over people" argument. It's people now vs people later. The infestation cycle is real, documented, and devastating.

If it were DDT or death, that would be one thing. Mr. Milloy admits it isn't, discusses some of the less effective mechanical remedies, and then dismisses other pesticides:

"...economical substitutes could be had. [for DDT in the US] But there is no economical substitute for DDT when it comes to malaria in poorer regions of the world."

Other pesticides. Other pesticides have been developed that are far more targeted than DDT. Pesticides that do not cause the infestation cycle.

It's like the difference between a carpet bombing and a cruise missile.

So what's the rub? Quoting Milloy: "there is no economical substitute for DDT."

It's the money, stupid. A nation that threw 200 BILLION DOLLARS and counting at a war in Iraq winces at the 200 MILLION dollars spent annually to help eradicate malaria in the third world.

Just use the DDT... It's cheap, and it's not our environment that will be destroyed or our crops that will be devoured in a few years by superbugs.

After all, helping the world's poor is important, but it's not that important. We have wars to wage, you know.

Maybe there are good reasons some people in the third world hate us.

Comments:
You make an excellent point, that broad spectrum insecticides create many more problems than they solve. And resistant strains of insects do evolve.

The same argument can be made about the current crop of anti-milarial drugs, which are becoming less effective over time.

The answer to the Milaria problem, like most diseases, is a vaccine. It appears that British researchers may have deveolped one, but it will not be ready for public use before 2010.

As far as your point about "A nation that threw 200 BILLION DOLLARS and counting at a war in Iraq winces at the 200 MILLION dollars spent annually to help eradicate malaria in the third world", that $200M is used for Bug Screens and Anti-milarials, NOT for eradication.

Now, whether it is moral and right to NOT use DDT or other insecticides until the prospective Milaria Vaccine is proven effective and safe, is something that needs to be considered. How many lives should we be willing to sacrifice in malaria prone areas, against the ecological damage we will cause?

I, and I am sure you would agree, believe that we should pour at least as much money and manpower into creating a Malaria Vaccine as we do into HIV/Aids. Especially when you consider the fact that Milaria will be a growing problem to the US as climate change continues.
 
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