Chemicals that induce mammary tumors or activate hormonal signaling are likely to increase breast cancer risk. A 2024 study identified over 900 breast cancer-relevant chemicals in current use, including mammary carcinogens, chemicals and ionizing radiation that activate estrogenic or progestogenic hormonal signaling pathways.  These chemicals include PFAS, benzenes, bisphenols, phthalates, halogenated and vinyl compounds, drinking water disinfection byproducts, benzidine-based dyes, and pesticide ingredients among others. Many are actively used as pesticide ingredients, but study results were previously dismissed by the US EPA Office of Pesticides, including for the widely used malathion, atrazine, and triclopyr. 

Take away: This study released a list of over 900 chemicals related to breast cancer furthering our understanding about chemicals that interfere with our hormone signaling pathways and increase breast cancer risk. These chemicals come from multiple sources ranging from plastics to products to pesticides and this publication guides efforts to reduce exposure to chemicals that cause cancer. Read more about breast cancer risk and pesticides, bisphenols, plastics, water pollution, and air pollution. Join our BCPP actions on bisphenols, PFAS in food packaging, PFAS in textiles, and PFAS in cosmetics. 

Link to Study

A 2024 study links the recent use of personal care products like lotions to higher levels of endocrine-disrupting chemicals called phthalates in young children. Phthalates are chemicals used in fragrances and added to plastics to make them more flexible and durable. These chemicals are endocrine disruptors – which means they can mimic, block or interfere with the body’s own hormones. Exposure to phthalates has been linked to impaired brain development, behavioral problems, and may be linked to early puberty. Low-molecular-weight phthalates (LMW) are frequently used in solvents, emulsifiers, and fragrance carriers in personal care products, whereas high-molecular-weight phthalates (HMW) are often used as plasticizers in polyvinyl chloride (PVC) and plastic packaging.

Take Away: Researchers measured phthalates in urine from 906 children and found that children who report lotion use had higher levels of two types of phthalates—one type comes from lotions and one type comes from plastic packaging. Study authors suggest “these results can help clinicians and advocacy groups to advise parents and guardians on product choices and use to limit children’s exposure to potentially hazardous phthalates/replacements.” Read more about phthalates and breast cancer risk. This is why BCPP is working to limit phthalates in personal care products, for example in our Toxic-Free Beauty Act. 

Citation: https://ehp.niehs.nih.gov/doi/10.1289/EHP13937  

Researchers recently reported in Nature that of the roughly 14,000 known chemicals in food packaging, about 25% have been found in the human body, in samples of blood, hair or breast milk. Those chemicals include metals, volatile organic compounds, per- and PFAS, phthalates and many others known to disrupt the endocrine system and cause cancer or other diseases. High temperatures can cause chemicals to leach more quickly into food, which is why scientists recommend avoiding microwaving food in takeout containers and avoiding plastic food containers as much as possible.

Learn more about what BCPP is doing to protect people from the toxic chemicals in food packaging.

Link to Study

A 20-year study conducted at UCLA with over 48,000 participants found that fossil fuel-based plastic and industrial toxic chemicals in the air were highly associated with breast cancer risk, especially among women of color. Chemicals in the air used to make PVC (#3) and polystyrene (#6) plastic, neither of which are recyclable, were among the chemicals most associated with breast cancer. African American participants exposed to higher vinyl acetate were more than 11 times more likely to develop breast cancer over the study period versus White study participants, whose had five times higher probability with higher vinyl acetate exposure. Higher vinyl chloride exposure increased breast cancer probability among Japanese Americans by seven times versus an increase of two times among White women.

Take Away: Plastic compounds, especially vinyl compounds, have been linked to breast cancer. This study found that 14 of 16 toxic air chemicals studied were associated with higher breast cancer risks. Some of the highest breast cancer associations were at exceedingly low levels of chemical exposure, so these findings show the importance of monitoring and reducing exposures to hazardous air pollutants, even at low levels, to prevent breast cancer. Read more about this study, air pollution, cancer risks from plastics, phthalates, PVC and BCPP actions on plastics.

Citation: https://www.sciencedirect.com/science/article/pii/S1438463924000439

A 2024 study from Harvard showed that women with higher PFAS levels in their 30’s had higher body fat 20 years later. The researchers studied 547 pregnant women in their early 30s, comparing their PFAS levels during pregnancy with cardiometabolic health outcomes at age 50. They found women with higher levels of PFAS in their blood during early pregnancy weighed more and had more body fat at 50 years old than those with lower levels, potentially making them more susceptible to obesity, breast cancer, and heart health problems later in life. PFAS exposure can be reduced by avoiding non-stick cookware, eating less-processed food, more plant foods, and making meals at home. Read more about PFAS and breast cancer. See BCPP actions on PFAS in food packaging, PFAS in textiles, and PFAS in cosmetics.

Citation: https://academic.oup.com/jcem/advance-article-abstract/doi/10.1210/clinem/dgae542/7745629