Chemicals and Breast Cancer

The evidence linking environmental contaminants with breast cancer risk has reached a critical mass; the potential relationship between the two can no longer be ignored. With the recent publication of the President’s Cancer Panel report on environmental pollutants and cancer, followed by the Institute of Medicine’s report on breast cancer and the environment, we are finally seeing a shift in the way the nation’s physicians and scientists think about how to prevent this deadly disease.

Rather than waiting for definitive proof that certain chemicals cause human harm before acting, many experts are calling for a new emphasis on cancer prevention that is focused on reducing and eliminating people’s exposures to toxic chemicals. It is unfeasible to rely on evidence from human studies in order to decide if a chemical is safe or not. Epidemiologic studies can yield meaningful results in the long-term, but they are unable to serve populations at risk in the short term—we cannot wait until a whole community has been exposed to a chemical for decades to see if it causes breast cancer. Instead, we need new strategies for identifying potentially harmful chemicals now and the various ways in which people come into contact with them.

Realizing this goal, however, will require investment in new research and changes in policy as scientists and regulators confront the challenges of addressing the thousands of chemicals currently in use. For instance, although we know a great deal about the toxic effects of certain chemicals—more than 200 chemicals so far have been linked to breast cancer in animal studies—new cost-effective screening tools are needed to test the thousands of other chemicals for which we have little or no data on chronic health risks. Given that people are exposed to myriad chemicals in different combinations over the course of their lives, a complete understanding of human exposure to contaminants will require better methods for measuring what people encounter every day, whether it be at work, at home, or in their community.

Silent Spring Institute is currently tackling these issues—and more—through its many research initiatives. The ultimate hope is that a national focus on environmental chemicals and breast cancer prevention will help shape new public health policies so that the burden is no longer on consumers to reduce their own exposures to hazardous chemicals, but on companies and regulators to ensure that the chemicals that make their way into consumer products are safe.