Stop The Fearmongering Over Cancer
June 1, 2010
Despite recent hysteria, cancer mortality rates have fallen throughout the past decade.
The cancer war is back! No, not the war against cancer that President Nixon declared back in 1971. That one never went away. What’s back is the war about cancer–what causes it and what we should do about it. The latest round of hostilities was initiated by the President’s Cancer Panel, a scientific advisory body that monitors the National Cancer Program. In its latest annual report the panel–which consists of two prominent scientists, surgeon LaSalle Leffall and immunologist Margaret Kripke–charged that the incidence of environmentally induced cancers has been “grossly underestimated.”
The major culprits, according to Dr. Leffall and Dr. Kripke, are the thousands of “understudied and largely unregulated” synthetic chemicals present in consumer products. In their cover letter to President Obama, they complain that an unsuspecting public is “bombarded continually with myriad combinations of these dangerous exposures.” They call on the government to “protect every American from needless disease through rigorous regulation of environmental pollutants.” They conclude by urging the president 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.”
I have quoted the panelists at some length because you really can’t appreciate the gist of their argument without seeing the actual language they used, which seems intended to incite public controversy. Note that, after expanding their mandate from carcinogens to all “toxins,” they manage to pull in such hot-button controversies as rising health care costs, fears of declining productivity and the dread that cancer holds for the popular imagination–heart disease may kill more people, but cancer devastates our lives.
All this reads more like an activist manifesto than an introduction to a scientific advisory report. In fact, the tone hearkens back to a furious debate that raged a quarter-century ago over a “cancer epidemic” that was allegedly engulfing America. The late 1970s and 1980s were the golden age of cancer scares, when hardly a news cycle seemed to go by without the discovery of some new carcinogen that was devastating American lives–air and water pollutants, artificial sweeteners like aspartame and saccharine, pesticides and herbicides like EDB and Alar, radiation from nuclear power plants and radon deposits, etc.
Unfortunately, many of these scares were mainly the products of media hype. A study of media coverage during those decades found that man-made chemicals were blamed for causing cancer even more often than tobacco. But the story the public was getting was wildly at variance with expert opinion.
A 1993 survey of the American Association for Cancer Research found that 65% of cancer researchers attributed rising cancer rates to the effects of tobacco and aging, compared to only 15% who blamed industrial activity. Even more (67%) said America did not face a cancer epidemic. And when they were asked to give their level of concern about various suspected causes of cancer, they rated such high-profile substances as Alar, EDB and dioxin below aflatoxin, a naturally occurring fungus in peanut butter, nuts and cereals. Moreover, all this shouldn’t have come as a shock; a 1984 survey of the same expert group had produced nearly identical findings.
Of course, that was then; this is now. Leffall and Kripke list numerous reasons we should be more concerned about chemicals than ever, despite the fact that the incidence of cancer and cancer mortality rates have both fallen throughout the past decade, as their report itself notes. For example, the toxicity of many chemicals approved by regulators has been tested singly but not in combination. There may be long latency periods before all the effects of recently developed chemicals emerge. The effects may be greater on children because of their lower body weights, and so forth.
These are all legitimate concerns and the subjects of ongoing scientific debate. But the panelists treat such potential dangers as sufficient reason to scuttle our current regulatory system and develop a new health policy agenda, based on a whole new paradigm for dealing with environmental cancer. Is such drastic action really warranted? Well, some of the same issues were addressed by a 2009 survey of the Society of Toxicology, the leading professional association for scientists who study chemical health risks. And just as in the past few of the scientific experts endorsed the doomsday scenarios.
Leffall and Kripke see grave danger in human exposure to even trace amounts of chemicals that cause cancer in laboratory animals at very high doses. But 92% of the toxicologists rejected the notion that any level of exposure to carcinogenic chemicals is unacceptable. (A basic premise of toxicology is “The dose makes the poison,” i.e., health risks depend not only on the substance but on the amount of exposure to it.) The panelists would require that chemicals be proved safe before they are approved; they reject the current system that permits their use in the absence of evidence that they are harmful. But 69% of toxicologists rejected this “precautionary” approach to chemical regulation, and only 23% rated Europe’s regulatory system, which is based on this precautionary principle, as superior to our own. Among synthetic chemicals, the panelists single out bisphenol A (BPA) for special concern. But only 9% of the toxicologists rated BPA as posing a high risk to human health, about one-third the number (26%) that ascribed a high health risk to our old friend aflatoxin.
The toxicologists are by no means Pollyannas about chemical risk. Majorities agreed with the panelists that pesticides pose a “significant” health risk and that environmental chemicals contribute to adverse reproductive health effects. But they didn’t seem to see an environmental cancer crisis or a broken regulatory system in need of replacement. Fewer than one in three rated any regulatory agency as understating chemical risks to human health. By contrast, most saw leading environmental activist groups and major media organizations alike as overstating these risks.