From Our 2010 Archives

Environmental Cancer Risk 'Grossly Underestimated'?

Presidential Panel Urges More Steps to Remove Carcinogens From the Environment

By Daniel J. DeNoon
WebMD Health News

Reviewed By Laura J. Martin, MD

May 6, 2010 -- "Grievous harm" from carcinogens in the environment has been "grossly underestimated" by the U.S. National Cancer Program, a presidential panel charges.

But the American Cancer Society says the panel's report goes too far in trashing established efforts to prevent cancer and that its conclusions go well beyond established facts.

The two-member President's Cancer Panel, appointed to three-year terms by President Bush, focused its efforts on environmental cancer risk. The panel held four hearings in which it consulted experts from environmental groups, industry, academic researchers, and cancer advocacy groups.

The panel's report includes an open letter to President Obama signed by panel chair LaSalle D. Leffall Jr., MD, of Howard University; and panelist Margaret L. Kripke, PhD, of the University of Texas M.D. Anderson Cancer Center.

"The grievous harm from this group of carcinogens has not been addressed adequately by the National Cancer Program," Leffall and Kripke write. "The Panel urges you most strongly to use the power of your office to remove the carcinogens and other toxins from our food, water, and air that needlessly increase health care costs, cripple our nation's productivity, and devastate American lives."

One of the panel's central claims is pollutants cause far more cancer than previously appreciated. In an October 2009 review, the Cancer and the Environment committee of the American Cancer Society's suggested that pollutants cause no more than 5% of all cancers.

The presidential panel says this greatly underestimates the problem because it does not fully account for synergistic interactions between environmental contaminants, an increasing number and amount of pollutants, and the fact that all avoidable causes of cancer are not known.

Experts differ on this assessment. Michael Thun, MD, of the American Cancer Society, writes that this opinion "does not reflect scientific consensus" but "reflects one side of a scientific debate that has continued for almost 30 years."

Richard Clapp, DSc, MPH, professor of environmental health at Boston University, praises the report for challenging "flawed and grossly outdated methodology." Clapp was among the experts who testified before the hearing.

"This is an attempt to update the science," Clapp said at a news conference sponsored by the Breast Cancer Fund. "This report ... calls for action on things where we don't yet know all the details. We shouldn't wait until the bodies are counted to say, 'Well, maybe people shouldn't be exposed so much to that chemical.'"

In its 240-page report, the panel calls on the National Cancer Program to emphasize environmental research, particularly so-called "green chemistry" that evaluates safety at the earliest stages of product development. It also calls for legislative and regulatory action to force industry to prove chemicals are safe before, not after, they are introduced into the environment.

Although he differs with the panel's rejection of current cancer prevention efforts, Thun says the American Cancer Society agrees with the panel's concern over:

  • Accumulation of certain synthetic chemicals in people and in the food chain
  • The large number of industrial chemicals that have not been adequately tested
  • The possibility that children are much more sensitive to environmental pollutants than adults are
  • Possible combination effects of low doses of multiple chemicals
  • Potential radiation risks from medical imaging devices

Presidential Panel's Advice for You

In addition to recommending sweeping changes in federal legislation and regulation, the panel also made a number of recommendations for how individuals can reduce their risk of cancer from environmental exposures in several areas.

As noted above, there is scientific disagreement over many of the panel's findings. These recommendations therefore do not necessarily represent scientific consensus.

Children:

  • Parents should realize that children may be particularly sensitive to environmental carcinogens. Parents and child care providers should choose foods, house and garden products, play spaces, toys, medicines, and medical tests that will minimize a child's exposure to toxins.
  • Both parents should avoid exposure to chemicals prior to a child's conception and throughout pregnancy.

Reducing chemical exposures:

  • Remove shoes before entering the house.
  • Wash work clothes separately from the rest of the family laundry.
  • Filter home tap or well water. Prefer filtered water to commercially bottled water.
  • Store and carry water in stainless steel, glass, or BPA- and phthalate-free containers.
  • Microwave food in ceramic or glass containers instead of plastic.
  • Try to choose foods grown without pesticides or chemical fertilizers.
  • Eat free-range meat raised without antibiotics, growth hormones, or exposure to toxic runoff from livestock feed lots.
  • Properly dispose of medications, household chemicals, paints, and other toxic materials that can contaminate the water or soil.
  • Turn off lights and electrical devices when not in use.
  • Drive fuel-efficient cars; find alternatives to driving.
  • Quit smoking and eliminate secondhand smoke in the home, car, and public places.

Avoid Radiation:

Cut exposure to electromagnetic energy by wearing a headset when using a cell phone, texting instead of calling, and keeping calls brief.

  • Periodically check home radon levels.
  • Reduce exposure to medical imaging devices by discussing the need for medical tests with health care providers.
  • Avoid overexposure to UV light by wearing protective clothing and sunscreen when outside, and by avoiding sun exposure when sunlight is most intense.

SOURCES: "Reducing Environmental Cancer Risk: What We Can Do Now," President's Cancer Panel, 2008-2009 Annual Report."

Fontham, E.T.H. CA: A Cancer Journal for Clinicians, published online Oct. 28, 2009.

News release, President's Cancer Panel.

News teleconference, Breast Cancer Fund, May 6, 2010.

American Cancer Society web site: "Cancer and the Environment" blog post by David Sampson, May 6, 2010.

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