The Panel was particularly concerned to find that the true burden of environmentally induced cancer has been grossly underestimated.
~ Letter to President Obama from the President’s Cancer Panel, April 2010
On May 21, I participated in a congressional staff briefing organized by the Collaborative on Health and the Environment and the Breast Cancer Fund in conjunction with Senator Dianne Feinstein and Representative Debbie Wasserman Schultz. The topic was the recently released President’s Cancer Panel report on the environmental links to cancer. Excerpts from my remarks appeared as a two-part essay in this space on June 8 and June 16. This essay looks at the public reaction to the report.
I first read the electronic version of the President’s Cancer Panel report, Reducing Environmental Cancer Risk: What We Can Do Now, in the dead of the night, moments after its midnight embargo was lifted on May 6. Nearly two months later, my paper copy arrived with the morning mail just as I was saying goodbye to vacationing houseguests—a beloved poet and his wife.
The title caught their eye, and so, while their kayak-topped car waited in the driveway, they settled into my living room couch with the report held open between them and silently started reading.
Finally, the beloved poet, Jim McGowan, held up the blue-jacketed document, with its rows of petri dishes on the front cover and the U.S. Department of Health and Human Services logo on the back, and asked, “May I have this?”
Jim had recently finished a course of radiation treatment for prostate cancer.
His wife, noting the plainspoken subheadings in the conclusions section—headings such as “The Nation Needs a Comprehensive, Cohesive Policy Agenda Regarding Environmental Contaminants and Protection of Human Health;” “Radiation Exposure from Medical Sources Is Underappreciated;” and “Medical Professionals Need to Consider Occupational and Environmental Factors When Diagnosing Patient Illness”— added, “It’s so
Anne McGowan is the retired director of the Ecology Action Center in Normal, Illinois. She’s led campaigns against lawn chemicals and watched with concern as pipelines have been laid across prime farmland to carry a slurry of human carcinogens in the form of crude oil from the tar sands of Alberta to Illinois refineries (TransCanada Corporation’s Keystone Pipeline began operating on June 30).
Over the past nine weeks, the President’s Cancer Panel report has been provoking passionate responses from across the country. In a recent editorial, the Los Angeles Times praised the report for broadening the discussion of cancer to include environmental carcinogens and for pointing out how woefully inadequate is our system of regulating them. Likewise, the National Council of Churches applauded the panel for its focus on children, who are more vulnerable to the harmful effects of chemical pollution and in whom cancer rates are rising.
By contrast, an editorial in Chemical & Engineering News condemned the report as alarmist, and the American Cancer Society called it “unbalanced.”
It’s easy to guess what the editor-in-chief of the American Chemical Society’s weekly magazine might find objectionable—perhaps the report’s conclusion entitled “Safer Alternatives to Many Currently Used Chemicals Are Urgently Needed.” But an attack by the nation’s leading cancer charity against a report that argues for cancer prevention via stronger environmental reform deserves a closer look. Especially since one of the report’s authors, oncologist LaSalle Leffall, is a former national president of the American Cancer Society. (And it was George W. Bush who appointed both Leffall and his coauthor, immunologist Margaret Kripke, to their posts—hardly preconditions for a radical takeover.)
At the heart of the American Cancer Society’s quarrel with the President’s Cancer Panel is a disagreement over a number. In their report, the panel appraises and ultimately dismisses an old but widely used heuristic: a 1981 pie diagram that attributes six percent of the human burden of cancer—currently about 34,000 deaths a year—to occupational or environmental exposures. The American Cancer Society defends this statistic.
The panel’s critique of the six percent figure is multitiered. First, the report points out that the derivation of this widely quoted estimate was based on flawed epidemiological methods. For example, older and non-white Americans were excluded from the original analysis. Second, it argues that the assumptions behind its derivation no longer reflect our current understanding of the biology of cancer initiation. Thirty years ago, cancer was thought to begin with a single genetic mutation.
Scientists now believe that the stage can also be set for cancer when chemical exposures trigger inflammatory processes, tinker with hormonal messages, or alter routes of development in early life in ways that can modify gene expression and so create vulnerabilities to carcinogens in later life.
The report also describes how cancer risk factors can interact with each other and with other risk factors in a cumulative fashion. In other words, environmental exposures are not so much a sliver in a great cancer pie as they are strands in a web of causation that interact with each other and with other risk factors, such as diet and lack of exercise.
Finally, the panel notes that environmental exposures have simply become “more diverse and numerous” over the past three decades. U.S. chemical production has more than doubled since 1981.
The panel does not attempt to replace the six percent number with another, noting that environmental exposures have diverse effects difficult to quantify. But it does conclude that the contribution of environmental exposures on the burden of human cancer has been “grossly underestimated.” However, the report concludes on a hopeful note, many opportunities for harmful environmental exposures mean there are also many opportunities for intervention and prevention of cancer through environmental protections.
The American Cancer Society does not rebut the various points of the President’s Cancer Panel argument. It simply holds to the six percent statistic as axiomatic and, from this vantage point, asserts that the report’s emphasis on environmentally induced cancers is “unbalanced” and thus a distraction from the risk factors it sees as bigger slices of the pie, such as tobacco addiction and obesity. In a world of limited resources, according to this logic, the time-honored message of smoking cessation and healthy lifestyle promotion offers more cancer prevention bang for the buck.
Thus, two opposing narratives about the role of the environment in the story of cancer—underlain by two different understandings about cancer causation, one new and one old—compete for our attention. And for the attention of the president.
The President’s Cancer Panel urges President Obama “to use the power of [his] 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.” The American Cancer Society counterargues that the President’s Cancer Panel has promoted an unproven theory as though it were fact—even as the society itself clings to an almost-30-year-old number that is more artifact than fact. President
Obama, we await your response.
Sandra Steingraber is the author of Living Downstream, newly published in second edition by Da Capo Press to coincide with the release of the documentary film adaptation. This essay is one in a weekly series by Sandra.
- published at www.livingdownstream.com