The recent report from the President’s Cancer Panel, entitled “Reducing Environmental Cancer Risk,”  took the bold step of focusing on environmental toxins and their role in causing cancer. In it, the authors charge that “the grievous harm from this group of carcinogens has not been addressed adequately by the National Cancer Program” and they urge 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 healthcare costs, cripple our nation's productivity, and devastate American lives.”

Much of the media chose to highlight the “personal responsibility” aspects of the panel’s recommendations for reducing cancer risk: Eating organic foods, avoiding toxic cleaning products, buying phthalate-free toys, filtering drinking water and avoiding unneeded medical scans, among other suggestions that are practical mostly for an upper-middle-class, educated audience–the media's target group.

But the Panel’s welcome—if surprising—endorsement of “green” living is not what makes the 200-plus page report so groundbreaking. What the authors have dared to do is call for a fundamental shift in direction for cancer research and prevention; away from the relentless pursuit of chemotherapy drugs and other treatments that provide incremental benefits—weeks or months of survival for a limited group at enormous cost—and toward an approach that focuses on taking meaningful steps toward reducing risk and preventing disease in the first place. They write:

“Environmental exposures that increase the national cancer burden do not represent a new front in the ongoing war on cancer. However, the grievous harm from this group of carcinogens has not been addressed adequately by the National Cancer Program. The American people—even before they are born—are bombarded continually with myriad combinations of these dangerous exposures.”

The NIH estimates that environmental factors contribute to 75-80% of all cancers. Tobacco smoke is one big culprit—responsible for one-third of the premature deaths from cancer, according to the American Cancer Society—as are ultraviolet light, radiation, obesity and certain viruses and sexually-transmitted diseases. Public health campaigns to reduce exposure to these cancer-causing agents—smoking cessation programs and bans, cigarette taxes, HPV vaccines and sunscreen promotion efforts—all offer the promise of reducing cancer incidence.

But the President’s Panel report calls these efforts too narrow. It is concerned about another, more insidious group of environmental carcinogens— the “nearly 80,000 chemicals on the market in the United States, many of which are used by millions of Americans in their daily lives and are un- or understudied and largely unregulated.”

Because industrial chemicals are so ubiquitous and exposure to these potential environmental carcinogens so widespread; “The Panel was particularly concerned to find that the true burden of environmentally induced cancer has been grossly underestimated.” This burden, according to one of the report's authors, Margaret Kripke, an emeritus professor at the University of Texas M.D. Anderson Cancer Center, is estimated as being just 6% of all cancers. That figure comes from a report issued way back in 1981 that has since been found to have serious flaws and limitations.

What’s remarkable about the Panel's report is that it doesn’t come from an environmental advocacy group, but from an advisory group that was originally established by the Nixon administration in its self-proclaimed “War on Cancer.” The panel’s two current members— Kripke and Dr. LaSalle Leffall, professor of surgery at Howard University College of Medicine and former president of the American Cancer Society—were appointed by President George W. Bush and reside solidly in the cancer mainstream.

Nevertheless, response to this report has been tepid or downright dismissive in some corners. Dr. Michael Thun, emeritus vice president of epidemiology at the American Cancer Society told the L.A. Times :

"'We agree that there are many important issues here … but a reader would come away from this report believing that pollutants cause most cancer.' In fact, he said, most cancers are caused by tobacco, alcohol, overexposure to ultraviolet light, radiation and sexually transmitted infections. The report 'presents an unbalanced perspective' of the relative importance of these various factors, he said."

Thun also took issue with a statement in the report that said the true burden of environmental pollutants is "grossly underestimated."

That, Thun said, is the view of some "but by no means a clearly established fact."

In the same L.A. Times article, Elizabeth M. Whelan, president of the American Council on Science and Health, a “consumer education consortium” that accepts industry funding, noted that despite the growing exposure to chemicals in the environment, "cancer death rates are going down. The so-called environmental trace levels of chemicals play no role whatsoever in the etiology of cancer."

These reactions, predictable as they may be, do a disservice to this comprehensive report. The President’s Cancer Panel Report is hardly presenting an “unbalanced perspective;” rather it is based on testimony from a series of meetings held between Sept. 08 and January 09 that included 45 invited experts from academia, government, industry, the environmental and cancer advocacy communities, and the public. (Click here to read the testimony from these hearings.) The issues discussed included such ubiquitous environmental risks as agricultural and industrial chemicals, medical radiation, naturally-occurring carcinogens like radon and electromagnetic fields, among others.

The President's Panel report clearly states that much work has to be done to better characterize environmental determinants of cancer—including better research methods, standardized measurements, and more realistic models that can help estimate the cumulative risks associated with multiple environmental toxins. Scientists who work on trying to establish the extent of these risks have for decades had to scramble for scarce funding from government and private sources that gave the work low priority. At the National Cancer Institute, the 2008 budget for occupational and environmental carcinogenesis and environmental epidemiology comprised less than 14 percent of NCI’s nearly $4.83 billion budget, according to the agency. The Occupational and Environmental Epidemiology branch received just $12.5 million in FY08 and received a 3% cut in FY09.

Meanwhile, says Richard Clapp, a professor at Boston University’s School of Public Health who has done extensive research on workplace exposure to industrial chemicals, NCI’s budget has doubled overall in the last ten years, with an “enormous emphasis on genome-wide association studies and molecular mechanisms research.”

In a consensus statement, the Collaborative on Health and the Environment, an international partnership of some 3,000 individuals and organizations, says that the net result of this inadequate funding is a body of research that is in danger of being irrelevant:

“The methods that have been used to attribute cancer risk to environmental exposures are outdated and flawed, and should no longer be used to determine policy or set research priorities.”

The fundamental problem is that research into environmental causes of cancer has little potential for yielding profits—at least in the short-term. In fact, it is more likely to cost industry through stronger regulation and removal of products from the market, litigation and the added expense of developing new products based on “green chemistry.” Is it any wonder then that between them, the government and the pharmaceutical industry would rather spend billions of dollars promoting screening and developing profitable new cancer drugs? Peter Montague, a long-time environmental advocate puts it this way: “To be blunt about it, there's no money in prevention, and once you've got cancer you'll pay anything to try to stay alive.”

Environmental carcinogens (aside from tobacco and sunlight) are rarely considered in health policy initiatives either, despite the very real findings that people who live in polluted areas and work with toxic substances (most often the poor and minorities) have higher rates of cancer incidence. The President’s Panel report gives the example of Louisiana and Mississippi, “known as ‘Cancer Alley’ because of the more than 100 chemical plants and oil refineries in the area and the high concentration of poor populations with limited health care access.” According to the report, “The cancer rate in Louisiana in 2005 was approximately 17 percent higher than the national average.”

The Center for Disease Control has multiple programs and initiatives aimed at preventing lung cancer (tobacco cessation) and melanoma/skin cancer (sun exposure education). But it does not set goals for reducing environmental and occupational exposures to toxins that increase cancer risk more broadly. It also doesn’t set a target for reducing specific disparities (based on race, income, occupation, etc.) in cancer incidence.

The panel authors stress that much still has to be learned about the environmental causes of cancer—especially the effects of a cumulative lifetime exposure to small amounts of multiple carcinogens. They are particularly concerned about children and the long-term ef
fects of in utero exposure to chemicals. According to the report;  “Tests of umbilical cord blood found traces of nearly 300 pollutants in newborns’ bodies, such as chemicals used in fast-food packaging, flame retardants present in household dust, and pesticides.”

After reading through this pithy new report one can't help but feel overwhelmed. Chemical toxins are all around us—in our food, air, water, at our workplaces and in our homes. Modern technology offers potential hazards as well—the electromagnetic radiation from our cell phones; radiation from MRIs and other medical imaging techniques; nanoparticles produced by high-tech manufacturing methods. It is easy to become numbed by the scope and the invisibility of the potential threat—it’s like global warming on steroids. It is far simpler to react like the American Cancer Society did and shrug off these risks as over-stated or non-issues.

The President’s Cancer Panel report is meant to be a wake-up call. Although it raises far more questions than it answers about environmental carcinogens and their role in causing cancer, it provides enough fodder to support a new focus—through funding, health policy and regulation—on reducing our exposure to environmental toxins. The first step will be to overhaul our current laws for regulating chemicals—an approach favored by the Obama administration as well as public health advocates.

In my next post, I will consider new toxics regulations that employ the Precautionary Principle—an idea that can best be described as “Better safe than sorry.” According to the Science and Environmental Health Network, the Precautionary Principle holds that “when the health of humans and the environment is at stake, it may not be necessary to wait for scientific certainty to take protective action.”

In Europe and Canada that principle is at the root of new regulations that require companies to demonstrate that their products are safe before they can be released into the environment. Here in the U.S., our out-dated toxic substances laws function the other way around; they place the burden on the government to prove that a chemical is unsafe before it can be tightly regulated or removed from the market. For example, scientists knew for many years that cigarette smoking caused lung cancer, yet it took 40 years before warnings were finally placed on boxes. In the meantime, smoking-related cancer deaths continued unabated.