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The War on Carcinogens vs. The War on Cancer
How misuse of animal tests and the war on "carcinogens" hurts America.

Elizabeth Whelan
March 11, 2005

One might argue that America is losing the War Against Cancer by conducting a War on "Carcinogens."

A thicket of current federal and state laws and regulations (including Superfund, Prop 65 in California, and EPA and FDA regulation of pesticides and food additives) assume that a rodent is a little man. Such laws cause substantial disruption of our nation's economic productivity (including inducing fear of safe foods and removal of safe consumer products) by banning any chemical that at high doses causes cancer in animals, as though it were necessarily a carcinogen for humans as well. This knee-jerk practice - based on no epidemiological evidence using human data - represents a threat not only to our quality of life - but also to our very lives and health.

Ask well-informed doctors how to reduce the risk of cancer, and they'll tell you that, to the extent we can reduce our risk of cancer (rather than being subject to genetic or as yet undiscovered causal factors), the best advice for patients has nothing to do eliminating or avoiding traces of industrial chemicals in food, air, or the general environment. Rather, the known preventable causes of cancer include:

  • Smoking. Smoking - particularly cigarette smoking - is the leading preventable cause of death in our society, and quitting (or better, not starting) is the best way to avoid a host of increased cancer risks.
  • Overexposure to sunlight. Too much sunlight increases risk of both superficial skin cancers and deadly malignant melanoma. So, easy on the beachgoing, and make use of shade and sunblock.
  • Obesity/Sedentary lifestyles. Obesity and inactivity increase cancer risk, including uterine cancer and, after middle age, breast cancer. There is some evidence that obesity is also associated with an increased risk of colon cancer.
  • Infectious/reproductive factors. Some sexually-acquired infections increase risk of certain cancers. The microbes involved include HIV, Human papillomavirus, and hepatitis B and C viruses. Multiple sexual partners increase the risk of cervical cancer via HPV infection.

The age at which women begin to menstruate, number of pregnancies and the age when first pregnant also influence risk of later cancer of the breast.

It might be reassuring to American consumers to know just how much we've learned about why cancer develops - and that we've learned a great deal both about prevention (with drugs as well as lifestyle changes mainly dealing with anti-smoking education) as well as treating it through surgery and pharmaceuticals. Early detection utilizing evidence-based screening tools, especially mammography and colonoscopy, have contributed to declining cancer mortality rates.

But instead of encouraging the public and medical professionals to focus on the well-established cancer causes, government and environmental activists chase after the phantom of trace levels of industrial chemicals, hoping to find a big-business scapegoat for our health fears. Worse, we enshrine these phantom cancer fears in regulation. Those regulations in turn shift the focus of scientific inquiry, as valuable lab time and scientific journal space is expended on finding out which chemical will be the next to fall afoul of the rat litmus test.

For nearly 50 years, American consumers have been the victim of unfounded health scares generated by activists trying to ban useful chemicals (like the sweeteners cyclamate and saccharin) because at high dose they cause cancer in rats. One of the most infamous scares was the Alar-apple panic of 1989, when actress-turned-toxicologist Meryl Streep and an activist environmental group (with no objection from the EPA) told us that apples treated with Alar posed an "intolerable risk" of cancer in children. Today, self-appointed consumer groups argue that French fries pose a cancer risk because the frying of high-starch foods produces a chemical called acrylamide. Environmental activists have also long been pushing for a ban on chlorine, a critical treatment to ensure water safety, because it is a rodent carcinogen.

The rodent-is-a-little-man premise has spawned unprecedented increases in environmental regulation (purportedly to protect us from cancer) and has contributed substantially to the cost of most goods and services, insurance premiums, legal fees, and federal taxes while reducing job opportunities and incentives for innovation - all without offering any known public health benefit whatsoever. Life-saving chemicals may be banned because they cause tumors in rodents and thus inspire baseless fears in the public.

This "rodent terrorism," for the lack of a better phrase, is the primary weapon in the arsenal of environmentalists, who reflexively attack any chemical tool used to improve human health, comfort, and well-being. Instead of quitting smoking, avoiding excessive sunlight, and taking other rational cancer prevention measures, the public has been frightened over and over again into following these nonsensical principles:

  • "To reduce cancer risk we must get rid of all cancer-causing chemicals." This is impossible. Animal carcinogens abound both in nature and man-made products. Environmentalists, with their "carcinogen of the week" scares, never address natural chemicals.
  • "No amount of carcinogens is safe." Not so. It is the dose that makes the poison. Trace levels of natural carcinogens don't harm us, nor does exposure to minuscule levels of synthetic chemicals - parts per trillion of pesticide residues in food, for one example. Sunlight causes cancer, but not at moderate exposures.
  • "We must rely on animal tests or we will have to wait until cancer occurs in humans!" No one is suggesting that we abandon animal tests - just knee-jerk interpretations of them. We should evaluate the cancer-causing potential of man-made chemicals, such as pesticides, the way we do naturally-occurring chemicals. For example, the government sets acceptable tolerance levels in wheat and corn for the naturally-occurring carcinogen aflatoxin, which clearly causes cancer in multiple species, instead of banning every last molecule of it.
  • "We must ban chemicals that cause cancer in animals so that cancer rates do not increase." Actually, public health specialists increasingly argue that animal cancer tests are ineffective in predicting human cancer risk. Rat experiments do not even reliably predict cancer risk in mice, much less humans! Banning chemicals that cause cancer in rodents not only does not prevent human cancer but promotes cancer by drawing attention and limited resources away from known, preventable causes of malignancies.

Congress can energize the American economy and help win the real war on cancer by revising the way the EPA and FDA and other federal regulatory agencies interpret one or a few animal cancer tests. There is no scientific basis whatsoever to conclude that a chemical is a "probable" or even a possible human carcinogen on the basis of the currently-applied high-dose rodent tests - but indeed, this is just what agencies such as the EPA do every day. They should, instead, test using the latest epidemiological science on the real causes of human disease - served up with a healthy dose of common sense.

Dr. Whelan is President of the American Council on Science and Health (, and an editor of the new book America's War on "Carcinogens": Reassessing the Use of Animal Tests to Predict Human Cancer Risk.

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