The Institute's Research

What kind of research does Silent Spring Institute conduct?
Silent Spring Institute scientists work to identify the links between environmental pollutants and women’s health, especially breast cancer. We focus primarily on chemicals in everyday products that cause mammary tumors in animals and those that can make breast cancer cells grow in a laboratory.

The Institute seeks to identify these chemicals and to develop new methods to assess exposure. Our studies use new methods to address the complexity of estimating a woman’s exposure to chemicals in the years or even decades before the discovery of her tumor. This information builds incrementally yet reliably.

Who does the research?
The Institute’s multidisciplinary research team includes experts in biology, chemistry, epidemiology, geographic databases, geology, health communications, information science, risk assessment, and toxicology. We have collaborated with investigators at Applied Geographics; the Boston University School of Public Health; Brown University; the Centers for Disease Control and Prevention; the Harvard School of Public Health; Roswell Park Cancer Institute; the State University of New York at Stony Brook; the Tufts University School of Medicine; the University of California, Berkeley; the University of Massachusetts Lowell; the University of Southern California; and others. The collaborative spirit that characterizes our work extends beyond the scientific community to include activists and others concerned about women’s health. Among these collaborators are colleagues at Communities for a Better Environment and the Massachusetts Breast Cancer Coalition.

What kinds of chemicals does Silent Spring Institute focus on—and why?
Our researchers focus on two types of chemicals: those that cause mammary tumors in animals and those that disrupt hormones. In particular, our scientists study chemicals in the environment that mimic estrogen. Natural estrogen is a well-established breast cancer risk factor; as a result, synthetic chemicals that act like estrogen when in our bodies are potential sources of increased risk of breast cancer. The chemicals we focus on have everyday sources—such as pesticides, detergents, and plastics—and can be found in our drinking water, household dust, and indoor air.

What are Silent Spring Institute’s current focus areas?
The Institute strategically targets scientific gaps in efforts to tease out environmental links to breast cancer. Our key focus areas include personal exposure to endocrine disrupting compounds; the safety of groundwater and drinking water; the natural alliance between breast cancer advocacy and environmental justice; the implications of sharing individual results from environmental health studies; and analytical leadership for breast cancer and environment advocacy.

Our ongoing projects include:

  • Breast Cancer and the Environment: Science Review
    In June 2007, the American Cancer Society’s journal Cancer published “Environmental Factors in Breast Cancer,” Silent Spring Institute’s comprehensive review of scientific research on environmental factors that may increase risk of breast cancer. In a 2007 article in Lancet Oncology, Silent Spring Institute co-investigators at Harvard reviewed research that shows that exposures in the womb may increase or decrease breast cancer risk later in life. Reviews on breast cancer and non-hormonal pharmaceuticals, and on endocrine disruptors toxicology are underway. In addition, now that we have assembled the most comprehensive list to date of chemicals that cause breast cancer in animals, we are working on a research agenda that will translate findings into public policy, develop better methods for testing additional chemicals, and apply the laboratory science in human studies.
  • Reducing Everyday Exposures at Home
    The Institute is building on its Household Exposure Study in several locations. In Massachusetts, we are developing a protocol to test whether making substitutions for cleaning, personal care, and other household products can reduce exposures to endocrine disrupting compounds, or EDCs. Additional Cape Cod data analysis will focus on phthalates, pesticides, and other EDCs with a goal of identifying sources of exposure and improving measurement strategies for health studies. In partnership with Communities for a Better Environment and researchers at Brown University and the University of California, Berkeley, the Institute is measuring household and outdoor pollutants in Richmond and Bolinas, California, and studying methods for reporting individual exposure data. The Institute is also extending its Household Exposure Study to other communities in Massachusetts and Rhode Island.
  • Linking Breast Cancer Advocacy and Environmental Justice
    Also in partnership with Communities for a Better Environment, Brown University, and the University of California, Berkeley, the Institute is expanding the dialogue between breast cancer and environmental justice constituencies, in California, Massachusetts, and Rhode Island. This study team is investigating the sources and cumulative impact of exposures in a low-income, predominantly Latino community that neighbors industry and transportation corridors.
  • The Ethics for Reporting Personal Exposures to Environmental Chemicals
    In September 2007 the Institute published results of its study on the ethical issues involved with delivering personal exposure results from chemical biomonitoring and environmental tests. Report-back from biomonitoring research has the potential to stimulate experiential learning about environmental pollutants, generating broad benefits in improved public understanding, individual risk reduction, influence on corporate practices, and increased participation in environmental public health policy. It also has the potential to be troubling for individuals who learn exactly what pollutants are in their bodies. The Institute is continuing to conduct interviews with study participants, activists, scientists, institutional review board members, and government health and environment officials to form the basis for developing recommendations on the ethical implications of reporting.
  • Environmental Health Tracking in Massachusetts
    The Institute is conducting outreach to a range of audiences to encourage use of the Massachusetts Health and Environment Information System, or MassHEIS, which combines health, demographic, and environmental databases into a single—and singular—web-based tool. One of the first publicly available sites of its kind, MassHEIS represents an important step in increasing the public’s access to essential health and environmental information and in sharing the Institute’s own research. Residents can learn about historical rates of cancer in their home communities and in other towns where they have lived, while researchers can access important underlying databases. Institute scientists are now investigating additional functionality and updating data for the web-based mapping tool.
  • Tracking Estrogens and Other Hormonally Active Pollutants in Cape Cod Groundwater and Drinking Water
    This project investigates the presence of estrogenic pollutants in Cape Cod groundwater, identifies them, and tracks their seepage from septic systems into groundwater. Tests of Cape Cod ponds measure endocrine disruptors that leach from septic systems into groundwater, which supplies drinking water. Institute researchers are also developing tools to detect previously unidentified endocrine disrupting compounds in wastewater.
  • Cape Cod Breast Cancer and Environment Study This study examines an area of elevated breast cancer incidence and investigates the links between increased breast cancer risk and exposures to mixtures of target environmental pollutants in wastewater and pesticides. The study has resulted in a number of discoveries. Notable, for example, is the finding that women who have lived longer on Cape Cod are at higher risk for the disease than new arrivals. Additional data analyses are ongoing; for more information, see Cape Cod Breast Cancer and Environment Study.
  • What has Silent Spring Institute accomplished so far?
    Since its founding in 1994, Silent Spring Institute has served as a pioneer in many areas. Among its accomplishments are:
    • The first geographic information system tailored to uncover environmental links to breast cancer.
    • The first identification of estrogenic activity in groundwater.
    • The first bioassay designed to determine the presence of endocrine disruptors in environmental samples.
    • The first-ever measurements of indoor exposure to 30 hormone disruptors.
    • The documentation of evidence that higher regional breast cancer incidence on Cape Cod, Massachusetts, cannot be explained by migration, mammography rates, or established risk factors.
    • The demonstration of widespread exposure to endocrine disrupting compounds in everyday environments.
    • An articulation of the case for concern about environmental pollutants and breast cancer, based on a comprehensive assessment of peer-reviewed scientific literature.
    • Forged connections between research and activism through dialogue and scientific support.
    • The collection and analysis of air and dust samples from 120 Cape Cod homes in the most comprehensive assessment to date of household exposures to estrogenic chemicals and chemicals known to cause mammary cancer in animals.
    • The reconstruction of decades of pesticide exposures at individual Cape Cod addresses through the development of a geographic information system, the first to assess how environmental factors on the Cape might be associated with increased breast cancer incidence.
    • The detection, in a Cape Cod sampling program, of specific endocrine disrupting compounds in private drinking water wells.
    • The identification of Fabulon, a wood floor finish commonly used in the 1950s and 1960s, as an important source of exposure to polychlorinated byphenols, or PCBs, 50 years later. (PCBs are endocrine disrupting compounds that affect thyroid hormone and the developing brain and have been associated with breast cancer.)
    • The first documentation that estrogenic chemicals seep from septic systems into groundwater.
    • The first measurements of flame retardant PBDEs in US homes, showing levels ten times higher than in Europe.
    • Reported to study participants on contaminants in their own homes and interviewed them about how they felt about learning their own results.