The link between chemicals and breast cancer

Vegetarian Times, April, 1997 by Amy O'Connor

A forthcoming study of Cape Cod residents is using innovative methods to find out whether synthetic chemicals in the environment are increasing breast cancer rates in that region. This groundbreaking research, slated for completion this summer, is one of the first projects -- and the largest -- to use both chemical analysis and geographic mapping to study breast cancer rates.

In the early 1990s, Cape Cod residents became alarmed when the state's public health agency found that breast cancer rates in seven of their communities were at least 25 percent higher than the state average. The authors of the Cape Cod Breast Cancer and Environment study suspected that the region's water system may be the culprit. The Cape is unique in that all of its drinking water comes from a single groundwater aquifer that may harbor unhealthy concentrations of toxic chemicals.

"The beautiful sandy beaches create a vulnerable ecosystem," says Julia Brody, Ph.D., executive director of the Silent Spring Institute, the independent scientific research organization conducting the study. To protect the ocean, wastewater is discharged further inland in septic tanks and lagoons and may pollute the drinking water. "Cape Cod has a history of substantial pesticide use," Brody says. Studies conducted at Harvard University's School of Public Health have suggested that exposure to some synthetic chemicals found in plastics, detergents and pesticides may increase the risk for breast cancer.

The Cape Cod study is in its third year, with results expected sometime in June. A similar breast cancer study is being conducted on Long Island, and breast cancer activists are trying to launch a third in San Francisco. Long Island, like Cape Cod, has a sandy geography and a history of substantial pesticide use, depends on groundwater as the sole source of drinking water and has unusually high breast cancer rates. "Twenty friends of mine were diagnosed," says Lorraine Pace, a breast cancer educator at the University Medical Center in Stonybrook, N.Y., and founder of Breast Cancer HELP (Healthy Environment for a Living Planet). "Our conversations were no longer about our kids but about our chemotherapy."

Although the association between chemical contaminants and cancer is unclear, public concern is mounting. Currently, breast cancer is the second leading cause of death in American women, and scientists believe environmental factors play a role in the disease. Breast cancer rates appear to be on the upswing, though the increase may be attributed to more sophisticated screening and better access to mammography. But 70 percent of diagnosed cases cannot be explained by recognized risk factors, such as heredity or diet.

Brody and other scientists believe there are preventable, environmental causes, "and we should make it a priority to find them." Yet studies of environmental causes have been limited because it is very difficult to make a cause-and-effect link. "The difficulty is that we want a black-and-white world," says Marion Moses, M.D., director of the Pesticide Education Center in San Francisco and consultant to the Long Island study.

Mary Wolff, M.D., a physician at the Mt. Sinai Medical Center in New York City and a member of the advisory board on the Cape Cod study, agrees that scientists are only beginning to learn how to study the effects of multiple chemical exposures on humans. Some new pesticides are eliminated quickly by the body, yet" it sometimes takes cancer 20 to 30 years to develop," she says.

Yet researchers involved in the Cape Cod study say they have the technology to clarify the association, using new computer mapping methods to analyze the relationships between breast cancer incidences and environmental data. They will also analyze medical records dating back almost 50 years and maps of all the drinking water wells, sewers and agricultural waste dumps, which are being compiled. Researchers are also sampling drinking water and waste using new chemical analysis for hormonal chemicals. The hope is to discern a pattern of breast cancer in highly contaminated areas.

Though breast cancer activists are pleased with the Cape Cod and Long Island studies, many are frustrated with the lack of funding for additional research into environmental causes. Although the National Cancer Institute is supporting the Long Island study, most cancer research focuses on "diagnosis and treatment, not prevention," says Jan Platner, executive director of the Massachusetts Breast Cancer Coalition. She and others believe many research institutions are too closely tied to corporations that oppose this kind of research, fearing results may lead to stricter regulation of chemical production. Nancy Evans, a member of Breast Cancer Action, an activist organization based in San Francisco says, "It's hard to know whether we should wait for research or start acting based on available evidence."