ADVERTISEMENT

The Search for Environmental Carcinogens

In the search for carcinogens, competing interests can complicate and compromise the case.

BY LAURA BEIL
PUBLISHED WEDNESDAY, MARCH 14, 2012
The news conference was held on Jan. 7, 1993, with breast cancer activists flanking Sen. Alfonse D’Amato (R-New York). The group was not satisfied with the findings of a study from the U.S. Centers for Disease Control and Prevention, which had just reported that elevated rates of breast cancer in Long Island could be explained by known risk factors. The women believed their illnesses had a deeper, more sinister explanation, perhaps a legacy of the agricultural roots of the now mostly affluent suburbs of New York City.

“We are taking matters into our own hands,” one of the women told reporters. And they did. With backing from D’Amato and other members of Congress, Public Law 103-43 was enacted later that year, directing the National Cancer Institute (NCI) and the National Institute of Environmental Health Sciences to study “environmental and other potential risks contributing to the incidence of breast cancer” in Nassau, Suffolk and Schoharie counties in New York and in Tolland County, Conn. The law instructed the investigation of environmental exposures, and even, to an unprecedented degree, how the studies were to be carried out.

"It was quite miraculous," says Karen Miller, founder of the Huntington Breast Cancer Action Coalition and a community advisor to the Long Island Breast Cancer Study Project. Few times in American history had ordinary citizens set the course of medical science. “There had never been a public outcry before,” she adds. But this was an era when advocates for breast cancer research were learning from AIDS activists about how to exert grassroots power over the scientific agenda.

“We each wanted to know, with a particular bent toward environment, why me?” Miller says. “What’s in the environment that contributed to my breast cancer?” In her view, and that of other Long Island women, government researchers were not looking hard enough or in the right places.

Almost 20 years later, the Long Island study and others have accumulated reams of data, yet experts remain troubled by the unanswered questions. The President’s Cancer Panel, appointed by President George W. Bush, concluded in 2010 “the true burden of environmentally induced cancer has been grossly underestimated.” It wasn’t just the statement, but the source, that got notice. Columnist Nicholas Kristof of The New York Times wrote, “It’s striking that this report emerges not from the fringe but from the mission control of mainstream scientific and medical thinking.”

We each wanted to know, with a particular bent toward environment, why me?

The science that connects any particular exposure to cancer takes a long and convoluted path, often with false starts and detours along the way. But there are other reasons why the identification of and protection against environmental exposures are not as straightforward as some people might hope. It’s not just that the science can be messy. Those who have a stake in the answer can influence the direction of research—as the Long Island women showed—to both the benefit and detriment of obtaining an answer. Sometimes patients themselves may fixate on the wrong threats. Sometimes industry, which benefits from as much scientific murkiness as possible, can keep doubt alive long after most scientists agree on an answer. (The tobacco industry proved to be quite successful at this technique.) And even after the research is done, different voices come to the table when government officials have to take the data and make decisions about which exposures need to be limited and by how much. “The landscape can get very complicated,” says Jonathan Samet, MD, director of the University of Southern California Institute for Global Health in Los Angeles.

The Toxic Substances Control Act, which was passed in 1976 and remains the law, does not require registration and health-effects testing of a chemical before it is put on the market (although it does require premanufacturing notification of new chemicals).

The Cancer Panel calculated that of the more than 80,000 chemicals in use today, only a few hundred have been tested for safety. We are literally born with them; nearly 300 chemicals have been found in umbilical cord blood. And even when something is known to cause cancer, that still doesn’t mean that it will be banned or that exposures will be heavily regulated. (Consider tobacco.)

That’s because, when deciding whether some exposure contributed to your cancer, the answer is: It depends.

“It depends on what it is and how you’re exposed,” Samet says. Something may be known to cause cancer but is still allowed on the market because the amount of exposure needed to cause cancer is more than someone would reasonably be exposed to. Or an exposure may cause cancer in animals, but not people. Remember the saccharine scares? Studies in animals in the 1970s suggested high levels of the artificial sweetener might contribute to bladder cancer. Only later did researchers determine that the cancer risk applied only to rats.

ADVERTISEMENT
Related Articles
Medicare to Cover Lung Cancer Screening
BY ELIZABETH WHITTINGTON
With the agency’s proposal to cover lung cancer screening, focus turns to implementation and increasing cures.
Avoid Carcinogens, Not the Grill This Summer
BY SONYA COLLINS
Cooking on the grill can add carcinogens to your meal. Here's how to avoid them.
Accuracy Matters When It Comes to Diagnosing Cancer
BY AIMEE SWARTZ
Biomarkers can estimate cancer risk, screen for the disease and confirm a diagnosis.
No Link Between Fertility Treatment and Overall Risk of Childhood Cancer
BY KATHERINE LAGOMARSINO
An analysis of several studies found the risk of cancer in children born through IVF is low.
ADVERTISEMENT
$auto_registration$