Atrazine: The Endocrine Disrupting Pesticide Causes Breast Cancer by Jeffrey Dach MD

Atrazine: The Endocrine Disrupting Pesticide Causes Breast Cancer by Jeffrey Dach MD The Trump administration has just re-authorized the pesticide atrazine for widespread agricultural use. Atrazine is one of the most heavily used herbicides in the United States, and the medical literature leaves no doubt: it is a potent endocrine-disrupting chemical (EDC) linked to breast cancer, other cancers, and infertility. In my office, I routinely advise women concerned about breast cancer risk to avoid EDC chemical exposures. Pesticides like atrazine act as hormone disruptors, interfering with estrogen, testosterone, and the hypothalamic-pituitary-gonadal axis. The result? Altered cell growth, suppressed immunity, and increased cancer risk. This is not speculation. It is documented in peer-reviewed studies. Header Image Attribution: Link to Photo on wikimedia commons. African clawed frog (Xenopus laevis), from Chimanimani in Manicaland, Zimbabwe. December 2012. Source Flickr: Xenopus laevis Author Brian Gratwicke. Creative Commons CC0 1.0 Universal Public Domain Dedication. Our Stolen Future by Theo Colborn One of the earliest and most influential warnings came in the groundbreaking 1996 bestseller Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival ? by Theo Colborn. This landmark book exposed how EDC synthetic chemicals in our environment threaten future generations. It laid the foundation for understanding endocrine disruption and specifically highlighted herbicides like atrazine as part of the problem. Decades later, the science has only grown stronger. Feminization of Male African Frogs Dr. Tyrone B. Hayes and his team at the University of California, Berkeley, published a landmark study showing that atrazine causes complete feminization and chemical castration in male African clawed frogs Xenopus laevis at extremely low, environmentally relevant doses (as low as 0.1 parts per billion). This work remains one of the most widely cited demonstrations of atrazine’s endocrine-disrupting power in vertebrates. Hayes, Tyrone B., et al. “Atrazine Induces Complete Feminization and Chemical Castration in Male African Clawed Frogs (Xenopus laevis) Proceedings of the National Academy of Sciences of the United States of America, vol. 107, no. 10, 9 Mar. 2010, pp. 4612–17 Increased Breast Cancer Rates On the human side, ecological studies have linked atrazine (and triazine herbicides) exposure in drinking water and agricultural areas to higher breast cancer rates. A widely cited 1997 study in Kentucky counties found a statistically significant increase in breast cancer incidence in areas with medium to high atrazine exposure. Kettles, M. A., et al. “Triazine Herbicide Exposure and Breast Cancer Incidence: An Ecologic Study of Kentucky Counties.” Environmental Health Perspectives, vol. 105, no. 11, Nov. 1997, pp. 1222–27, A similar ecological analysis in Missouri counties reached comparable conclusions. Hunter, L. D., et al. “Atrazine Exposure and Breast Cancer Incidence: An Ecologic Study of Missouri Counties.” Toxicological & Environmental Chemistry vol. 90, no. 2, 2008, pp. 293–307, Mechanism of Action More recent laboratory and animal work confirms the mechanism. A 2023 study in Ecotoxicology and Environmental Safety showed that atrazine promotes breast cancer development by suppressing immune function and upregulating matrix metalloproteinases (MMPs), accelerating tumor growth, invasion, and spread in mouse models. Wang, M., et al. “Atrazine Promotes Breast Cancer Development by Suppressing Immune Function and Upregulating MMPs.” Ecotoxicology and Environmental Safety vol. 253, 15 Mar. 2023, article 114691, Breast Cancer in Mouse Models Chronic exposure studies in female Sprague-Dawley rats, the gold-standard model for mammary tumor research, showed increased incidence and earlier onset of mammary tumors linked to prolonged estrus and elevated estrogen/prolactin signaling. Wetzel, Lawrence T., et al. “Chronic Effects of Atrazine on Estrus and Mammary Tumor Formation in Female Sprague-Dawley and Fischer 344 Rats.”Journal of Toxicology and Environmental Health, vol. 43, no. 2, 1994, pp. 169–82, doi:10.1080/15287399409531914. In November 2025, the International Agency for Research on Cancer (IARC) classified atrazine as “probably carcinogenic to humans” (Group 2A), citing sufficient evidence in animals (including mammary tumors), limited human evidence for non-Hodgkin lymphoma, and strong mechanistic data on hormone disruption, oxidative stress, and immune suppression. Cattley, Russell C., et al. “Carcinogenicity of Atrazine, Alachlor, and Vinclozolin.” The Lancet Oncology, vol. 27, no. 1, Jan. 2026 , pp. 11–12, Conclusion: Atrazine is an endocrine disrupting chemical with documented links to breast cancer and other serious health effects. Re-authorizing its use puts millions at unnecessary risk, especially in agricultural communities where it contaminates drinking water. In my practice, I emphasize prevention. For women on bioidentical hormone programs, I routinely recommend iodine supplementation (such as Lugol's Solution or Iodoral) as part of a breast cancer prevention strategy, precisely because environmental EDCs like atrazine increase risk. If you are concerned about atrazine or other pesticides, talk to your doctor, filter your water, and support policies that protect public health over corporate profits. The science has been warning us for decades, Our Stolen Future told us this was coming. It is time to listen. Link to related articles: Pesticides and Breast Cancer Connection Jeffrey Dach MD 7450 Griffin Road, Suite 190 Davie, FL 33314 954-792-4663 my blog: References Hayes, Tyrone B., et al. “Atrazine Induces Complete Feminization and Chemical Castration in Male African Clawed Frogs (Xenopus laevis).” Proceedings of the National Academy of Sciences of the United States of America, vol. 107, no. 10, 9 Mar. 2010, pp. 4612–17, doi:10.1073/pnas.0909519107. https://www.pnas.org/doi/10.1073/pnas.0909519107. Kettles, M. A., et al. “Triazine Herbicide Exposure and Breast Cancer Incidence: An Ecologic Study of Kentucky Counties.” Environmental Health Perspectives, vol. 105, no. 11, Nov. 1997, pp. 1222–27, doi:10.1289/ehp.971051222. https://pmc.ncbi.nlm.nih.gov/articles/PMC1470339/. Hunter, L. D., et al. “Atrazine Exposure and Breast Cancer Incidence: An Ecologic Study of Missouri Counties.” Toxicological & Environmental Chemistry, vol. 90, no. 2, 2008, pp. 293–307, doi:10.1080/02772240701529012. https://www.tandfonline.com/doi/abs/10.1080/02772240701529012. Wang, M., et al. “Atrazine Promotes Breast Cancer Development by Suppressing Immune Function and Upregulating MMPs.” Ecotoxicology and Environmental Safety, vol. 253, 15 Mar. 2023, article 114691, doi:10.1016/j.ecoenv.2023.114691. https://www.sciencedirect.com/science/article/pii/S0147651323001951. Wetzel, Lawrence T., et al. “Chronic Effects of Atrazine on Estrus and Mammary Tumor Formation in Female Sprague-Dawley and Fischer 344 Rats.” Journal of Toxicology and Environmental Health, vol. 43, no. 2, 1994, pp. 169–82, doi:10.1080/15287399409531914. Cattley, Russell C., et al. “Carcinogenicity of Atrazine, Alachlor, and Vinclozolin.” The Lancet Oncology, vol. 27, no. 1, Jan. 2026 , pp. 11–12, doi:10.1016/S1470-2045(25)00702-8. https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(25)00702-8/fulltext. Colborn, Theo, et al. Our Stolen Future: Are We Threatening Our Fertility, Intelligence, and Survival? A Scientific Detective Story. Dutton, 1996. EPA Weakens Safeguards for Weed Killer Atrazine, Linked to Birth Defects The reversal is the Trump administration’s third about-face on a toxic pesticide. By Gosia Wozniacka November 20, 2019 CivilEats Jeffrey Dach MD 7450 Griffin Road, Suite 190 Davie, Fl 33314 954-792-4663 My Web Site my personal blog: www.jeffreydachmd.com Bioidentical Hormones 101 Second Edition Menopausal Hormone Replacement, Health Benefits Natural Thyroid Toolkit by Jeffrey Dach MD Cracking Cancer Toolkit ebook Cracking Cancer Toolkit print version Heart Book by Jeffrey Dach MD www.naturalmedicine101.com www.bioidenticalhormones101.com www.truemedmd.com www.drdach.com Click Here for: Dr Dach’s Online Store for Pure Encapsulations Supplements Click Here for: Dr Dach’s Online Store for Nature’s Sunshine Supplements Web Site and Discussion Board Links: jdach1.typepad.com/blog/ disc.yourwebapps.com/Indices/244066.html disc.yourwebapps.com/Indices/244067.html http://sci.med.narkive.com/covV2Qo2/jeffrey-dach-book-announcment-natural-medicine-101 Disclaimer All characters or patient names appearing on this web site or copied elsewhere are purely fictitious. Any resemblance to real persons, living or dead, is purely coincidental. The reader is advised to discuss the comments on these pages with his/her personal physicians and to only act upon the advice of his/her personal physician. Also note that concerning an answer which appears as an electronically posted question, I am NOT creating a physician — patient relationship. Although identities will remain confidential as much as possible, as I can not control the media, I can not take responsibility for any breaches of confidentiality that may occur. Link to this Article Copyright © 2025 Jeffrey Dach MD All Rights Reserved. This article may be reproduced on the internet without permission, provided there is a link to this page and proper credit is given. See Repost Guidelines. FAIR USE NOTICE: This site contains copyrighted material the use of which has not always been specifically authorized by the copyright owner. We are making such material available in our efforts to advance understanding of issues of significance. We believe this constitutes a ‘fair use’ of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes. Serving Areas of: Hollywood, Aventura, Miami, Fort Lauderdale, Pembroke Pines, Miramar, Davie, Coral Springs, Cooper City, Sunshine Ranches, Hallandale, Surfside, Miami Beach, Sunny Isles, Normandy Isles, Coral Gables, Hialeah, Golden Beach ,Kendall,sunrise, coral springs, parkland,pompano, boca raton, palm beach, weston, dania beach, tamarac, oakland park, boynton beach, delray,lake worth,wellington,plantation

Jeffrey Dach MD

Bioidentical Hormones Natural Thyroid

Category Archives: Atrazine

Atrazine: The Endocrine Disrupting Pesticide Causes Breast Cancer by Jeffrey Dach MD