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Your Environment. Your Health.

Environmental Chemicals and Postpubertal Breast Composition in a Latino Cohort

Breast Cancer & the Environment Research Program

University of California, Los Angeles
Silent Spring Institute
Fox Chase Cancer Center
University of Chile

Principal Investigators:
Karin B. Michels, Sc.D.
Julia G. Brody, Ph.D.
Camila Corvalán, M.D., Ph.D.
Jose Russo, M.D.

Ruthann Rudel

NIEHS Grant: U01ES026130

Other Community and Academic Partners:
University of California, San Francisco

Sporadic breast cancer is a hormone dependent malignancy with a steadily increasing incidence. Although the reasons for this increase are uncertain, epidemiologic findings support an important role for environmental pollutants containing endocrine disrupting chemicals (EDCs) and their metabolites. The last six decades have witnessed a massive introduction of hormonally active synthetic chemicals into the environment. Therefore, exposure to EDCs at critical windows during the life course may play a role in changing the susceptibility to breast carcinogenesis.

This project is exploring whether exposure to three environmental compounds with different endocrine-disrupting pathways, butyl perfluorooctanoic acid (PFOA), benzyl phthalate (BBP), and zeranol, during the pubertal period will alter breast composition and/or the susceptibility to breast cancer. The researchers are building on an existing puberty cohort of 400 Latino girls in Chile for whom breast composition measurements at Tanner stage 4 are already available. They are extending this cohort to add an assessment of breast composition two years after menarche as a tracker of breast density from this point into adulthood. The team is studying the influence of the three chemicals, PFOA, BBP, and zeranol, individually and in combination, on breast composition in these Latino girls.

To explore whether pubertal exposure to PFOA, BBP, and zeranol has deleterious effects on mammary gland biology and susceptibility to carcinogenesis, they also are studying the morphology, transcriptome, and tumorigenesis of the rat mammary gland exposed to these compounds. Results from this work will be disseminated via community outreach to family members of study participants and community members in Chile. Furthermore, the research team is connecting this project and BCERP with breast cancer advocacy in the United States, creating opportunities for translation into personal and policy changes to promote health.

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