Breast Cancer and Environmental Research Act of 1999 - Amends the Public Health Service Act to require the Director of the National Institute of Environmental Health Sciences to make grants to public or nonprofit private entities for the development and operation of not more than eight centers for the conduct of multidisciplinary research on environmental factors that may be related to the etiology of breast cancer. Requires each center to: (1) conduct basic and clinical research; (2) develop protocols for training health professionals; (3) conduct training programs for such individuals; (4) develop model continuing education programs for such professionals; and (5) disseminate information to such professionals and the public. Authorizes a center to provide stipends for professionals enrolled in the program. Allows grant support for a center for up to five years, with authorized extensions. Requires an equitable geographic distribution of such centers. Authorizes appropriations for FY 2000 through 2005.