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De Omnibus Dubitandum - Lux Veritas

Monday, December 29, 2008

DDT and Chlordane Killed By Politics, Not Science

I would like to thank Harry Katz, who is a legendary defender of our industry and the products we use, for allowing me to re-publish this 1998 article and I hope to use more of his articles. This article was published before many of the new products became available, but his points regarding why these two safe and reliable products were taken off the market are worth reporting and worth repeating. We must keep the history correct; no matter what regulators claim or impose….we must know the history, we must remember the history…correctly. History is the stepping stones to the future. Harry Katz was there and he remembers the events as they occurred….let’s not allow ourselves to be beguiled by the latest philosophical flavor of the day. RK

By Harry Katz

A lie becomes the truth if it is repeated often enough. This has happened, I believe, with the boomer generation that grew up weaned on the Myth Conception that DDT is carcinogenic. According to Carrol Weil, past president of the Toxicology Society, there have never been any valid scientific tests that prove DDT can cause cancer in test animals or in humans.

Numerous tests were made on animals, mostly mice that were bred to be supersensitive to chemical stress. The mice were given massive doses of DDT long periods of time. Tumors did develop, but they did not metastasize into cancer cells. Many of the mice that were not fed DDT also developed tumors.

This didn’t matter to the Environmental Protection Agency. EPA regulations consider a benign tumor to be a cancer that justifies cancellation of registration. It should be noted that according to EPA regulations, a single positive test by one researcher takes precedence over the negative test results of 100 researchers.

LOW VS. GROSS DOSE. One of the Myth Conceptions that plagues the mindset of the general public, as well as various regulatory communities, is that a low dose of a toxicant is just as bad as a gross dose that can cause a tumor. If this were true, according to Dr. Bruce Ames from the University of California-Berkeley, we should not eat carrots, celery, parsley, mushrooms, cabbage, Brussels sprouts, mustard, orange and grapefruit juices, pepper, cauliflower, broccoli, raspberry and pineapple. All these foods contain natural toxicants that cause cancer in rats or mice when they are tested at the same gross levels that are used to test pesticides. Ames further claims that the natural level of toxicants in these foods is far higher than the trace residues on treated foods.

The Myth Conception of the carcinogenicity of DDT has a corollary with chlordane. According to the World Health Organization (WHO), when chlordane is used at label rates, there is no valid scientific test that shows carcinogenicity in humans. In 1984, a working group of the International Agency for Research on Cancer (IARC) reviewed existing data on chlordane and concluded that the evidence of carcinogenicity to experimental animals was indeed limited.

CHLORDANE’S EFFECT ON HUMANS. Many studies were made of chlordane’s effect on humans. The WHO reports about a study in 1981 in which mortality of 782 workers who manufactured chlordane and heptachlor for up to 20 years showed no increase in cancer in comparison to normal death figures. In another study by Wang and MacMahon in1980, all cancer deaths were lower than expected. In a follow-up study in 1982, the two Harvard researchers looked again at the mortality rates of termite control technicians and found there was no significant increase of cancer cases.

As secretary of the Western Pennsylvania Pest Control Association and as a formulator, I was concerned about the safety to PCOs. A Pittsburgh physician, Dr. Cyril Wecht consented to give annual physicals to employees of WPPCA members. In those days, the service technicians used chlordane carelessly. They had it on their hands, clothes, and breathed it in crawlspaces. Dr. Wecht found no effect on the liver or other vital organs, after several years of examinations.

MORE EXPENSIVE, LESS EFFECTIVE. There is much ado about the misapplication of termiticides. The regulators’ preoccupation with spacing of holes has little relationship with the concentration of toxicant in each cubic inch of soil. Backfills are usually a hodgepodge of building debris, hunks of clay and roots from dead foundation plantings. The most conscientious technician who carefully measures the concentrate and calibrates the flow of solution cannot be sure that every cubic inch of soil barrier is properly treated. Termites have nothing else to do but to look for that window of opportunity, an untreated pocket of soil.

In the Mallis Handbook of Pest Control, 8th Edition, Dr. Michael Potter claims that liquid dilutions tend to disperse randomly over the subslab fill, resulting in inconsistent coverage, and diversion from target areas.

If government tests of termiticide efficacy were made using the same label procedures mandated for PCOs, we would have no registered termiticides. As tested, the label should call for removal of the backfill to be treated, then mixing it with the termiticide solution in a cement mixer and finally replacing the mixture in the ditch. Fill material to be covered with a slab should also be treated the same way. Further, in testing for the presence of toxicant years later, multiple cores should be mixed and then tested.

The regulatory communities, who are looking for a fall guy to blame for the rash of termite control failures, ignore this double standard. Perhaps the officials should look in the mirror. When they killed relatively innocuous chlordane, they forced the public to pay three or more times the cost for termite control with no increase in safety and with limited residual value.


  1. If we fail to understand the question, we'll get the answers wrong most of the time.

    First, DDT was banned because it kills wildlife and destroys entire ecosystems. The "ban" stopped only broadcast spraying of DDT in the U.S., generally agricultural use. There was a specific waiver for emergency use and to protect health (which was used at least once in the U.S.).

    There is no study that shows DDT can be rendered harmless, but hundreds of studies that show its harmful effects multiply as it bioaccumulates up the food chain. DDT is death on a stick for top predators, especially birds like the bald eagle, osprey, brown pelican and peregrine falcon. Ending broadcast DDT use in the U.S. allowed the recovery of the bald eagle, and its removal from the endangered species list.

    I don't know where Katz gets the idea that DDT is not carcinogenic. Repeated studies have found it carcinogenic, though weakly so in large mammals (like humans). DDT is a known mammal carcinogen, and it is listed as a "probable carcinogen" in humans by every cancer fighting agency on Earth. Katz may not realize he's calling the American Cancer Society liars, but he is. Frankly, I trust the Cancer Society more -- their record fighting cancer is longer and deeper.

    EPA regulations don't consider benign tumors to be cancers. There is no regulation on any toxic that comes close to that description. EPA banned DDT because it wipes out ecosystems. Actually, the "ban" involved only a change in registration for the stuff, prohibiting broadcast spraying of DDT on agricultural crops. Broadcast spraying had already caused cataclysms by the middle 1960s. Mosquitoes were resistant to it -- bedbugs were immune, having first shown strong resistance to DDT as early as 1948. The idea was to stop the overuse of DDT.

    This statement is false: "DDT was banned because EPA thought it was carcinogenic to humans." If we repeat that statement often enough, even good people will believe it to be true. There is a robust campaign to spread that falsehood, and it has achieved some success.

    But the science against DDT is strong, and it doesn't involve cancers in humans.

    Truth wins in a fair fight, Ben Franklin observed. Let's scrupulously preserve fairness in scientific debates about the use of poisons to produce our food, fiber and health.

  2. Wrong Ed Darrell. The American Council on Science and Health in 1998, Harvard and numerous other studies and reports cleared DDT of any safety issue to humans, animals or aquatic life. DDT was a scapegoat to the leftist eugenics crowd setting a precedent for EPA power to control the People. Ruckleshaus admitted that he banned DDT for political reasons while ignoring the facts that DDT was harmless.

    DDT saved WWII vets. and citizens in Italy during 1943. It saved holocaust survivors infested with lice and fleas from dying. People fed it to their children in the late 1940's that had intestinal worms. Gordon Edwards ate DDT for years.
    Rachael Carson was a nutcase who wrote a novel based on a gothic tale. Robin populations flourished during DDT use and had healthier clutches. Bird shell thickness was a problem before DDT was ever sprayed. You know too much that is wrong.
    DDT was exhaustively tested for years for safety, and there is not one single case of it causing cancer or any other illness in a human, animal, or fish. You are in denial my friend. Read truth instead of fiction.

  3. P.S. there would not be an American Cancer Society if they released a cure. Which does exist by the way. Because cures are not profitable. You probably trust big pharma too. Treating problems is where the big $ are, not solving them. Follow the money. The American Cancer Society wants to continue existing and collecting millions $, so why would they like a cure.... Think about it.