July 2, 2005

DDT - bad for the environment?

Two links on the touchy subject of DDT. Touchy because there is so much bad science and hype surrounding a very useful chemical. First: The Straight Dope
Was Rachel Carson a fraud and is DDT actually safe for humans?
Claiming Silent Spring (1962) is full of lies is a bit harsh. Let's say it contains certain statements at variance with the facts as we now understand them. I'm willing to believe this was a natural result of the fledgling state of environmental science at the time, whereas right-wing conspiracy theorists (who apparently include the parties you mention--Hecht supports crank-for-all-seasons Lyndon LaRouche) see it as evidence of a campaign of deceit by the liberal cabal. We could spend pages debating the details, but the bottom line is this: Soaking the biota in DDT like it was bubble bath, standard practice at the time Silent Spring was written, was a bad thing and Carson was right to condemn it. But refusing to use DDT because of exaggerated fears of environmental damage is, in some circumstances, far worse.

Rachel Carson, a biologist and writer who worked for many years for the U.S. Fish and Wildlife Service, is widely credited with catalyzing the modern environmental movement. Silent Spring was the first popular book to call attention to the dangers of indiscriminate introduction of pesticides and other chemicals into the environment. Carson's principal target was DDT (if you really want to impress the ladies, Craig, tell them it stands for dichlorodiphenyltrichloroethane), a cheap and effective insecticide first employed on a large scale during World War II to control typhus and malaria. After the war DDT was widely used in the United States in agriculture and in mosquito abatement programs.
This article sums it up nicely -- we were as it says: "soaking the biota in DDT like it was bubble bath..." and this is not good. To put a 100% overall ban on its use is not the appropriate response though, especially when dealing with environmental disasters like the over one million deaths from Malaria each year that could be brought to a dead stand-still with a light dusting of DDT on the walls inside people's houses. One more paragraph from this article:
I don't mean to suggest that DDT is benign. On the contrary, it's a potent contact toxin, and though it breaks down quickly in sunlight, it's much more persistent in soil and water and accumulates in plants and fatty animal tissues with long-term exposure. But its drawbacks have to be weighed against its benefits. Malaria currently infects 300 to 500 million people annually, mostly in Africa, and causes as many as 2.7 million deaths. Alternative methods of mosquito control cost more and are less effective. Some 400 scientists and doctors have signed a petition opposing the inclusion of DDT among the 12 persistent organic pollutants (POPs) to be banned under a United Nations treaty now up for ratification, and a few public health experts are campaigning to bring DDT back. DDT isn't a panacea; India, which still uses it, suffered nasty outbreaks of malaria in the 90s, and insects in many parts of that country have become resistant to the chemical. But it remains an important tool, and in a time of rising global pestilence we shun it at our peril.
The second link: Junk Science
100 things you should know about DDT
Things 17, 18 and 19:
Extensive hearings on DDT before an EPA administrative law judge occurred during 1971-1972. The EPA hearing examiner, Judge Edmund Sweeney, concluded that "DDT is not a carcinogenic hazard to man... DDT is not a mutagenic or teratogenic hazard to man... The use of DDT under the regulations involved here do not have a deleterious effect on freshwater fish, estuarine organisms, wild birds or other wildlife."
[Sweeney, EM. 1972. EPA Hearing Examiner's recommendations and findings concerning DDT hearings, April 25, 1972 (40 CFR 164.32, 113 pages). Summarized in Barrons (May 1, 1972) and Oregonian (April 26, 1972)]
Overruling the EPA hearing examiner, EPA administrator Ruckelshaus banned DDT in 1972. Ruckelshaus never attended a single hour of the seven months of EPA hearings on DDT. Ruckelshaus' aides reported he did not even read the transcript of the EPA hearings on DDT.
[Santa Ana Register, April 25, 1972]
After reversing the EPA hearing examiner's decision, Ruckelshaus refused to release materials upon which his ban was based. Ruckelshaus rebuffed USDA efforts to obtain those materials through the Freedom of Information Act, claiming that they were just "internal memos." Scientists were therefore prevented from refuting the false allegations in the Ruckelshaus' "Opinion and Order on DDT."
Time for a change eh? Posted by DaveH at July 2, 2005 10:01 PM | TrackBack

DDT is very harmful and should not be used for the cause of environmental damage.

Posted by: Bob Marley at April 18, 2006 9:13 AM
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