Is there evidence that the environment in Marin is contributing to breast cancer risk?
A. Although there is no doubt environmental factors may play a role in the development of breast cancer, several studies have provided indirect evidence that the Marin County environment is not making a large contribution to elevated breast cancer rates. The Marin County Residence, School, and Workplace Study did not find sufficient evidence to conclude that years lived or worked in Marin were associated with an increased risk of developing breast cancer. A map of breast cancer rates by residence at time of diagnosis in Marin found that census tracts in Marin had similar rates of breast cancer, and that tracts with higher rates were not geographically related, nor related to the location of prior military bases or other areas of suspected environmental toxins. Extensive testing of the water supply in Marin has failed to reveal evidence of pesticides, estrogenic substances, or other known carcinogens.
