The Pesticide Myth

It's hard to say what scares New Yorkers more: The mosquitoes bearing West Nile virus or the pesticides used to control the mosquitoes. You wouldn't think this would be a close call.

Seven New Yorkers died and 62 were sickened by West Nile virus last summer. But "no disease has ever been documented that stems from legal applications of pesticides," according to Dr. Philip Landrigan of the Mt. Sinai School of Medicine, a staunch pesticide opponent.

In the wake of this week's spraying of Central Park, a New York Times editorial endorsed pesticide hysteria, stating, "It is an understandable concern, given [the] fear that the very groups most endangered by the virus — the young, the elderly and those with immune deficiencies — could react badly to insecticides."

But the editorial's authors apparently never saw the film clips of Nazi concentration camp survivors — it's difficult to imagine people in a more compromised state of health — who upon liberation were drenched with the pesticide DDT to kill disease-bearing lice. Not only did DDT save many survivors' lives, but there are no reports in the scientific literature of adverse health effects from the soaking — another reality check for the Times' "fear."

The two pesticides used in New York so far this year — known by the trade names Anvil and Scourge — are more effective, manmade versions of the natural pesticide pyrethrum produced by chrysanthemum flowers. Any human exposure to these chemicals will likely be hundreds of times lower than levels causing effects in laboratory animal studies. Properly applied, Anvil and Scourge are not expected to cause environmental problems.

What are the origins of pesticide hysteria? There are two watershed events: the publication of Rachel Carson's book Silent Spring in 1962, and the banning of DDT by the U.S. Environmental Protection Agency in 1972. Silent Spring scared the public about pesticides and rallied anti-chemical activists. The ban validated public fear.

Carson said that DDT harmed bird reproduction and that DDT caused cancer. Ominous chapter titles included "Elixirs of Death," "And No Birds Sing," and "The Human Price." But Carson misrepresented the existing science on bird reproduction and was wrong about DDT causing cancer.

She wrote "Dr. [James] DeWitt's now classic experiments [show] that exposure to DDT, even when doing no observable harm to the birds, may seriously affect reproduction. Quail into whose diet DDT was introduced throughout the breeding season survived and even produced normal numbers of fertile eggs. But few of the eggs hatched."

DeWitt's 1956 article in the Journal of Agriculture and Food Chemistry actually yielded a very different conclusion. DeWitt reported no significant difference in egg hatching between birds fed DDT and birds not fed DDT. Carson also omitted mention of DeWitt's report that DDT-fed pheasants hatched about 50 percent more eggs than "control" pheasants.

As for DDT causing cancer in humans, study after study reports no association between DDT exposure and cancer rates.

But as wrong as Carson was, the EPA's conduct was worse.

Anti-DDT activism led to hearings before an EPA administrative law judge in 1971. After seven months and 9,000 pages of testimony from all sides of the DDT controversy, 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."

Despite the exculpatory ruling, then-EPA administrator William Ruckelshaus banned DDT anyway.

Ruckelshaus never attended the hearings, did not read the transcript and refused to release the materials used to make his decision. He even rebuffed a U.S. Department of Agriculture effort to obtain those materials through the Freedom of Information Act, claiming they were just "internal memos."

It gets worse.

Ruckelshaus was biased against DDT. He was a member of the activist group, the Environmental Defense Fund. Ruckelshaus solicited donations for EDF on personal stationery that read, "EDF's scientists blew the whistle on DDT by showing it to be a cancer hazard, and three years later, when the dust had cleared, EDF had won."

But as an assistant attorney general a year earlier, Ruckelshaus stated in a federal court that "DDT has an amazing, an exemplary record of safe use, does not cause a toxic response in man or other animals, and is not harmful. Carcinogenic claims regarding DDT are unproven speculation."

In a May 2, 1971 address to the Audubon Society — the parent organization of the EDF — Ruckelshaus said, "As a member of the Society, myself, I was highly suspicious of this compound, to put it mildly. But I was compelled by the facts to temper my emotions... because the best scientific evidence available did not warrant such a precipitate action."

Another telling part of the DDT saga was unveiled during a lawsuit by scientists claiming the Audubon Society and the New York Times defamed them as "paid liars" about DDT. Depositions revealed that EDF and Audubon Society leaders plotted to silence and discredit scientists who defended DDT. The scientists won a jury verdict.

Still, the DDT myth — and pesticide hysteria — persists. Some fault lies with the chemical industry's tendency to reformulate and move on rather than fight for the facts.

Not everyone believes the DDT myth. U.S. government malaria experts wrote recently in the journal Emerging and Infectious Diseases, "Today, DDT is still needed for malaria control. If the pressure to abandon this effective insecticide continues,... millions of additional malaria cases worldwide [will result]... We are now facing the unprecedented event of eliminating, without meaningful debate, the most cost-effective chemical we have for the prevention of malaria. The health of hundreds of millions of persons in malaria-endemic countries should be given greater consideration before proceeding further with the present course of action."

New Yorkers should also engage in "meaningful debate" about pesticides. Proper pesticide use is a powerful tool in our public health arsenal — not something to be feared, especially on the basis of junk science.

— Steven Milloy is a biostatistician, lawyer, adjunct scholar at the Cato Institute and publisher of