What types of compounds are priorities for breast cancer research at Silent Spring Institute?

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, therefore, 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 common sources, including pesticides, detergents, plastics, and air pollutants from motor vehicles and other combustion, and can be found in our drinking water, household dust, and indoor air.

Are there other cancers and illnesses that have environmental causes?

Yes. There are a number of diseases with documented environmental causes: lung cancer and cigarette smoking, oral cancer and use of chewing tobacco, mesothelioma and asbestos inhalation, leukemia and exposure to benzene, and melanoma and/or breast cancer and exposure to radiation.

What do studies of wildlife tell us about the effects of the environment on development and reproductive health?

For several reasons, including the intimate relationship they have with the environment that surrounds them, wildlife are often the first to exhibit the harmful effects of environmental pollutants. They are sentinels, warning of dangers as yet undetected in other populations.

The effects that pesticides and other compounds that can disrupt hormones have on embryonic development or reproductive functioning in wildlife have been shown in many studies. For example, studies of male fish in rivers in Europe showed they developed both male and female reproductive organs after exposure to endocrine disrupting pollutants in their environment. Other, more recent research on the effects of the pesticide atrazine, showed that at very low levels, the pesticide demasculinized tadpoles, causing them to develop as hermaphrodites, that is, to have both male and female sex organs and sexual characteristics.

What does the precautionary principle mean to environmental research on health-related issues?

The precautionary principle allows scientifically sound and ethical decisions to be made on environmental and public health problems. Specifically, the principle shifts the burden of scientific proof on the effects a substance has on humans and the environment: It calls for precautionary measures to be taken whenever there is a possibility that an activity or substance could be harmful to humans or the environment, even if some cause-and-effect relationships are not fully established scientifically. Environmental research on health-related issues can contribute to the body of evidence used in these decisions.