Atrazine

also see wildlife/ amphibians , insects, and endangered species. reproductive health, Respiratory,  Pesticides 101, Organics/farming, water

SNAP Comment: As of 5 January 2024, There are stll 12 atrazine containing insecticides registered in Canada. It is licensed for use in field, seed, and sweet corn, sorghum and switchgrass. Who knows, we may see its use increasing in Saskatchewan with an increase in corn crops. It was the number one use herbicide in the US, to be dethroned by glyphosate. Now it is second. Dr. Tyrone Hayes mentions forestry uses. This is apparently not the case in Canada. In September 2026, 17 (from 66 historically) atrazine containing pesticides registered in Canada,an increase of 5 products   It is listed for use on corn in Saskatchewan in AAtrex and Primextra II Magnum formulations.  As it easily travels via the atmosphere, it can easily reach Saskatchewan in weather systems coming from the South. 

Hormone-disrupting herbicide contaminating 25% of continental US rivers, report finds (The Guardian,  28 Septembr 2026)     Atrazine, banned in 60 countries, polluting rivers at levels that can harm wildlife and may threaten human health. The hormone-disrupting herbicide atrazine is contaminating nearly 25%, or about 860,000 miles, of all continental US rivers at levels that can harm wildlife and may threaten human health, a new review of federal records has found. The waterways cover over 20% of surface drinking water intakes across the country, and over 675,000 private and commercial wells.   Atrazine can be particularly harmful to reproductive systems, and is linked to the “feminization” of the male gonads, irregular menstrual cycles, lower sperm counts, poor semen quality and lower fecundity in men and women.   “At the time (1990s) it was known that atrazine was the most common pesticide contaminant in drinking water, rain, surface water, and groundwater. You name it – atrazine was there,” Hayes told the Guardian. He noted it also travels via the atmosphere, and the US government found atrazine sprayed in Kansas can rain down on Minnesota.   “The effects are very clear, and in my opinion there is no safe level at which atrazine can be used because it is active in amphibians at .1 ppb, and there can be atrazine at 100 times that in rainfall,” Hayes added.    SNAP Comment: 17 (from 66 historically) atrazine containing pesticides registered in Canada in September 2026. It is listed for use on corn in Saskatchewan in AAtrex and Primextra II Magnum formulations. As it easily travels via the atmosphere, it can easily reach Saskatchewan in weather systems coming from the South. 

THE PESTICIDE PUZZLE   A Look at Agricultural Chemicals (Real Ag series, 19 Dec 2023) 30 minute very interesting video giving a good introduction to pesticides.    It features a case study on atrazine by reknowned biologist Dr. Tyrone Hayes. PAN Senior Scientist, Marcia Ishii (PhD Ecology and Evolutionary Biology), shares her knowledge on the ecological, social and political dimensions of pesticides in food and agriculture. Rob Faux (Fox) speaks about the benefits of agroecological practices based on two decades of growing experience.

Tyrone Hayes official site. Tyrone Hayes (University of California- Berkeley) has been hammered by Syngenta after he found that the herbicide had drastic effect on feminizing frogs. 

Tyrone has done many presentations on his research on atrazine. The latest is: Endocrine disruption, environmental justice, and the ivory tower | Tyrone Hayes | TEDxBerkeley (March 8, 2018)

Tyrone also gave many talks at Beyond Pesticides conferences such as 14 Keynote: Tyrone Hayes, PhD: Protecting Life, From Frogs to the Human Family (March 2018)

also see Reproductive Health

page updated 6 August 2019

NFU comments on Special Review of atrazine February 12, 2016

Degenerative Lung Diseases Associated with Atrazine Exposure, Worsened in Combination with Common Cancer Treatment    (Beyond Pesticides, December 2, 2021) A study published in Cellular Physiology and Biochemistry finds atrazine (ATR) exposure worsens lung disease outcomes in individuals with idiopathic (spontaneous) pulmonary fibrosis (IPF), a group of incurable lung diseases involving damaged/scarred lung tissue. Furthermore, chemotherapeutic products used to treat lymphoma (immune system cell cancer) like bleomycin can induce pulmonary fibrosis complications exacerbated by pesticide exposure. 

EPA finds two widely used pesticides harm majority of endangered species (By Ashley Curtin, Nation of Change November 17, 2021) US story.   Atrazine and glyphosate are both causing severe harm to many of the plants and animals protected under the Endangered Species Act. “It’s no surprise that these chemical poisons are causing severe harm to imperiled wildlife since U.S. use exceeds 70 million pounds of atrazine and 300 million pounds of glyphosate every year,” Nathan Donley, environmental health science director at the Center for Biological Diversity, said.   SNAP Comment: While atrazine use is low in Saskatchewan (11 kg in 2003), likely because there was hardly any corn production at that time, glyphosate was the top selling herbicide in 2003 with over 9 million kgs sold (9/10th of total commercial sales based on 75% reporting). Note that atrazine is widely used in southern Ontario and Quebec at the very least.

Atrazine Found to Harm Marsupial Health    (Beyond Pesticides, August 12, 2020) 'The herbicide atrazine can interfere with the health and reproduction of marsupials (including kangaroos and opossums) kangaroo, Virginia opossum, according to research published in the journal Reproduction, Fertility, and Development.  Researchers found changes to the gene expression necessary for basic function of the testis, and a significant reduction in phallus length. “These results demonstrate that atrazine exposure during gestation and lactation can significantly affect the development of male young by affecting virilization,” the authors write.' The doses  were slightly higher than real world models,   'Worse yet, EPA is set to reregister atrazine for another 15 years of hazardous use.'    SNAP Comment: There are still 12 atrazine registered products in Canada as of 6 September 2020.While there are no opossums in Saskatchewan,there are some in other parts of Canada.

Toxic Herbicide Atrazine Causes Wasp Gut Microbiome to Develop Pesticide Resistance Across Generations  (Beyond Pesticides, February 11, 2020)   This study not only represents one of the first evolutionary studies on symbiont-mediated pesticide resistance, it also provides fodder for future research regarding the implications of exposure to xenobiotics (i.e., chemical substances like toxic pesticides foreign to an organism or ecosystem) for other gut bacteria hosts – such as honey bees and humans. Early generations of wasps in the study received a field-realistic dose of atrazine (300 ppb) or a subtoxic dose (30 ppb); exposed individuals showed a gut flora composition significantly different from the control group. The shift in microbiome composition persists across subsequent generations.   After the 8th generation of sublethal dosing, there was a significant increase in tolerance to atrazine. LC50 increased in later generations of the atrazine-exposed population, indicating pesticide resistance. The paper reads, “Our study is one of the few cases to experimentally evolve cooperation between a host animal and rare members of the microbiome to derive new fitness traits within the population.”   Even when wasps are switched to an atrazine-free diet for six generations, the bacterial composition was similar to that of the exposed parents. Overall, researchers observed an increase in microbiota diversity and bacterial load.'