Etiology and Prevention Spotlight

Women Worker Biomonitoring Collaborative (WWBC)

PIs: Rachel Morello-Frosch, UC Berkeley, Erin Carrera, UCSF Nurse & Heather Buren, SFFD

Women firefighters and nurses work on the front lines to protect community well-being, yet little is known about their exposures to chemicals, particularly potential breast carcinogens. This study compared chemical exposures between three professions: female nurses, office workers, and firefighters, to explore links between occupational exposures and breast cancer risk. Over a hundred participants provided blood and urine samples, which were analyzed to detect possible carcinogens and other chemicals. The study yielded valuable insights and developed a new workflow strategy combining biomarkers and metabolomics to better capture chemical exposures. Recently awarded additional funding from the California Breast Cancer Research Program, the team will now focus on targeted analysis of chemicals like phthalates, bisphenols, and parabens. The study generated 46 publications and has strengthened partnerships with nurses and firefighters, who are actively involved in identifying relevant exposures, and the future study aims to provide clearer results for participants. Recently the team highlighted how community-based participatory research (CBPR) can drive broad social change while advancing scientific knowledge.

Reducing Latina Women's Exposure to Cleaning Chemicals

PIs: Kim Harley, UC Berkeley & Norma Morga, Clinica de Salud del Valle de Salinas

The Lifting Up Communities through Interventions and Research (LUCIR) study examined how household cleaning products expose Latina women to harmful chemicals that may increase breast cancer risk, and whether switching to "green" or low-chemical alternatives could lower their exposure. Co-led by the CHAMACOS Youth Council in Salinas, California, this project empowered high school students to take part in research, education, and advocacy. The study found that using green cleaning products significantly reduced air levels of harmful chemicals like benzene, chloroform, and toluene — but that even some products labeled as “green” still contained fragrances that could cause harm, indicating that fragrance-free options may be safer. Student scientists and their community contacts embraced the findings, with 98% saying the green products worked just as well, and 90% willing to keep using them. Alongside the research, the youth involved gained valuable skills and created educational videos to help others reduce chemical exposure at home. The project generated three publications, including a paper in the journal Indoor Air and Environmental Health Perspectives.

In vivo impact of xenoestrogen exposure on the human breast

PIs: Shanaz Dairkee, California Pacific Medical Center Research Institute & Polly Marshall, Breast Cancer Over Time

How do chemicals in personal care products — like phthalates and parabens — affect breast tissue and cancer risk? Researchers teamed up with a motivated group of breast cancer survivors to design a study where participants switched to phthalate- and paraben-free PCPs for one menstrual cycle. They compared breast cell samples before and after the switch and found something striking: genes linked to cancer risk shifted toward a more "normal" pattern when participants stopped using products with these chemicals. Despite challenges due to COVID-19, they successfully gathered samples and found strong evidence that cutting out these chemicals could reduce breast cancer risk. They also noticed that participants’ urine had lower paraben levels, confirming reduced exposure. This study suggests that even "safe" levels of these chemicals might be harmful over time — but reducing exposure could reverse some of the damage, lowering breast cancer risk. These results were published in Chemosphere.