A study published on September 23, 2026, in Environmental Health Perspectives identified 485 substances present in pesticide products that may promote breast tumors. The research, led by Jennifer Kay, cross-referenced over 900 substances suspected of triggering breast tumors in animals or disrupting hormones against a dozen public American databases. The study found that 145 of these breast cancer-linked pesticides are still authorized as active ingredients in the United States, and many are also present in water and food. The research highlights that current controls usually focus on the active molecule, while people ingest and breathe the entire pesticide formula. The main problem lies in so-called inert adjuvants, which are classified as inert but escape tests conducted on the active principle. These adjuvants accompany the product from the field to the plate and many act as endocrine disruptors, mimicking or blocking hormones that control tissue growth. According to Jennifer Kay, the evaluation of a pesticide should not stop at its star molecule, since exposure is to the complete mixture. These compounds are found in food, tap water, some medications, everyday products, and even in building materials. Federal biological monitoring has detected 84 of these in the human body, indicating that these substances have already largely penetrated the organism of a large part of the population. Some pesticides are even massively widespread. More than 90% of Americans carry traces of organophosphates such as malathion, and DDT remains detectable in more than 40% of the population, decades after its ban. These molecules indeed stick to fats and soils for a long time, so they continue to circulate long after their use has ended. An individual thus accumulates, without knowing, the residues of several generations of treatments. The list maps risks, it does not condemn any particular product. Due to the lack of direct human trials, researchers cannot definitively establish that any of the 485 compounds causes breast cancer. The study only identifies chemical properties and mechanisms compatible with the disease, such as the ability to mimic estrogens, not an established cause-effect link. The authors see this more as a map of exposures to reduce in priority. For Ruthann Rudel, co-director of the research, the approval of new pesticides still pays too little attention to these effects on the breast. The authors now call for evaluating the entire formulations and measuring the actual exposure of populations, two blind spots that no current protocol really covers.