CCOB is concerned with the potential for the aggregate washing operation to concentrate pesticide & herbicide residue into the wash pond from which may directly enter our aquifer. One of the most commonly used pesticides in our area is Atrazine. This page will highlight the dangers of Atrazine. Click here to see how this relates to gravel pits – Potential Risks from Pesticide Residues & Aggregate Washing.

Atrazine is largest selling herbicide made by the largest chemical company in the world. It is the number one contaminate of ground water, drinking water & rain water & was banned in the EU in 2003. The current science shows that Atrazine has some serious side effects, however, you will find contradictory science. Considering the serious nature of the effects, the precautionary principle should apply and Atrazine should be banned until it can be proven without a doubt that it has no effect. The major suspected effects are breast cancer and the world-wide decline in amphibian populations.

Breast Cancer:

Atrazine is known as an “endocrine disruptor” that turns on the production of aromatase resulting in an increase of estrogen production, which promotes the growth of cancer. The leading breast cancer drug is a chemical called Letrozole, which blocks the production of aromatase and therefore, estrogen. The most interesting aspect is that the same company makes both Atrazine and Letrozole. Prostate cancer is another concern.

Mass extinction:

We are currently losing species faster than the dinosaurs disappeared – with amphibians leading the way. Studies by Tyrone Hayes reveals that when male frogs are exposed to Atrazine, their testosterone production is basically shut off and the production of estrogen is turned on, chemically castrating these frogs. Similar effects have been found in birds, fish & mammals.

Why is Atrazine still allowed in Canada? You will see from the information contained on this page that there is enough science to raise concern. You will also note that the behaviour of the company is quite suspicious as well. The is a current lawsuit against the government of Canada for continuing to allow this & other harmful pesticides. Experience shows that our government will only consider the science submitted by the company.

Tyrone Hayes + Penelope Jagessar Chaffer: The toxic baby

Filmmaker Penelope Jagessar Chaffer was curious about the chemicals she was exposed to while pregnant: Could they affect her unborn child? So she asked scientist Tyrone Hayes to brief her on one he studied closely: atrazine, a herbicide used on corn.

Demasculinization and feminization of male gonads by atrazine: Consistent effects across vertebrate classes

A review of the science performed by 22 different scientists showing consistent results.

Atrazine is the most commonly detected pesticide contaminant of ground water, surface water, and precipitation. Atrazine is also an endocrine disruptor that, among other effects, alters male reproductive tissues when animals are exposed during development. Here, we apply the nine so-called “Hill criteria” (Strength, Consistency, Specificity, Temporality, Biological Gradient, Plausibility, Coherence, Experiment, and Analogy) for establishing cause–effect relationships to examine the evidence for atrazine as an endocrine disruptor that demasculinizes and feminizes the gonads of male vertebrates. We present experimental evidence that the effects of atrazine on male development are consistent across all vertebrate classes examined and we present a state of the art summary of the mechanisms by which atrazine acts as an endocrine disruptor to produce these effects.

Atrazine demasculinizes male gonads producing testicular lesions associated with reduced germ cell numbers in teleost fish, amphibians, reptiles, and mammals, and induces partial and/or complete feminization in fish, amphibians, and reptiles. These effects are strong (statistically significant), consistent across vertebrate classes, and specific. Reductions in androgen levels and the induction of estrogen synthesis – demonstrated in fish, amphibians, reptiles, and mammals – represent plausible and coherent mechanisms that explain these effects. Biological gradients are observed in several of the cited studies, although threshold doses and patterns vary among species. Given that the effects on the male gonads described in all of these experimental studies occurred only after atrazine exposure, temporality is also met here. Thus the case for atrazine as an endocrine disruptor that demasculinizes and feminizes male vertebrates meets all nine of the “Hill criteria”.
Download the full PDF here: Demasculinization and feminization of male gonads by atrazine

There Is No Denying This: Defusing the Confusion about Atrazine

A research paper that clearly shows us why the controversy about Atrazine exists.
Recent studies from my laboratory, showing the chemical castration (demasculinization) and feminization of amphibians by low but ecologically relevant concentrations of atrazine in the laboratory and in the wild, prompted a critical response from atrazine’s manufacturer, Syngenta Crop Protection, and Syngenta-funded scientists. A careful analysis of the published data funded by Syngenta, and of several studies submitted to the US Environmental Protection Agency (EPA) by the Syngenta-funded panel for data evaluation, indicates that the data presented in these studies are not in disagreement with my laboratory’s peer-reviewed, published data. Further, the published and unpublished data presented to the EPA by the Syngenta-funded panel (and touted in the popular press) suffer from contaminated laboratory controls; high mortality; inappropriate measurements
of hormone levels in stressed, sexually immature animals during nonreproductive seasons; and contaminated reference sites. The confounding factors in the industry-funded studies severely limit any conclusions about the adverse effects of atrazine on amphibians and prevent meaningful comparisons with my laboratory’s published data.
Click here to download the full PDF: hayes2004 confusion about atrazine


The Paris Pit site has previously been used for agriculture, mainly for corn production, up until 2014. During this period, atrazine and other herbicides had been in regular use. Atrazine has been detected in groundwater samples but there is concern that the sampling methodology does not provide a comprehensive and accurate assessment of the levels of atrazine at the site.

As described in this witness statement, there are significant environmental and health effects associated with exposure to herbicides including atrazine. The studies in experimental animals have found evidence of health impacts affecting the reproductive, hepatic, and hypothalamic-pituitary systems. The results of studies in human populations are mixed, but are strongly suggestive of human health impacts. These data are not unexpected as there are confounding factors involved in human studies including verification of exposure, exposure to other chemical agents, life-style factors, and others.

In my opinion, the results of the available studies taken together demonstrate that a precautionary approach should be adopted, especially for vulnerable groups, to protect citizens from the risks of exposure to atrazine and its metabolites.
Click here to download the full PDF: Poh-Gek Forkert Witness Statement (Volume 1 and 2)


Pesticide banned in Europe found in Toronto’s tap water

Toronto may be an hour from the nearest farm, but environmental groups say unsafe levels of a top-selling herbicide used on cornfields for the last 50-odd years are turning up in our tap water.

Tests commissioned by Environmental Defence and Équiterre have found atrazine in both Toronto and Montreal’s drinking water at levels that would flunk European safety standards.

“It’s quite alarming,” says Environmental Defence’s toxics manager, Muhannad Malas. “Torontonians are probably exposed to atrazine on a daily basis.”


Tyrone B. Hayes – Case Study of Atrazine and Environmental Health

Silencing the Scientist: Tyrone Hayes on Being Targeted by Herbicide Firm Syngenta

Democracy Now! speaks with scientist Tyrone Hayes of the University of California, Berkeley, who discovered a widely used herbicide may have harmful effects on the endocrine system. But when he tried to publish the results, the chemical’s manufacturer launched a campaign to discredit his work. Hayes was first hired in 1997 by a company, which later became agribusiness giant Syngenta, to study their product, Atrazine, a pesticide that is applied to more than half the corn crops in the United States…

Special Report: Syngenta’s campaign to protect atrazine, discredit critics.

To protect profits threatened by a lawsuit over its controversial herbicide Atrazine, Syngenta Crop Protection launched an aggressive multi-million dollar campaign that included hiring a detective agency to investigate scientists on a federal advisory panel, including looking into the personal life of a judge and commissioning a psychological profile of a leading scientist critical of Atrazine.

The Switzerland-based pesticide manufacturer also routinely paid “third-party allies” to appear to be independent supporters, and kept a list of 130 people and groups it could recruit as experts without disclosing ties to the company.
Recently unsealed court documents reveal a corporate strategy to discredit critics and to strip plaintiffs from the class-action case. The company specifically targeted one of Atrazine’s fiercest and most outspoken critics, Tyrone Hayes of the University of California, Berkeley, whose research suggests that atrazine feminizes male frogs. full article…



After Tyrone Hayes said that a chemical was harmful, its maker pursued him. full article…

Biologist Tyrone Hayes battles one of the biggest agribusinesses in the world

Biologist Tyrone Hayes has spent his career studying the effects of one particular herbicide – Atrazine – on frogs. When he presented the maker Syngenta with results that he said showed sexual abnormalities in frogs, Dr. Hayes says the company tried launched a campaign to discredit his work.

Atrazine Studies

Demasculinization and feminization of male gonads by atrazine: Consistent effects across vertebrate classes

Click here to download the full PDF: Demasculinization and feminization of male gonads by atrazine
*note – many more studies are referenced at the end of this document

Click here to download the full PDF: There Is No Denying This: Defusing the Confusion about Atrazine

*note – many more studies are referenced at the end of this document
Click here to download the full PDF: hayes2004 confusion about atrazine
*note – many more studies are referenced at the end of this document

Poh-Gek Forkert Witness Statement (Volume 1 and 2)
*note – many more studies are referenced at the end of this document

 U.S. EPA, Toxicity and Exposure Assessment for Children’s Health

Atrazine Exposure in Public Drinking Water and Preterm Birth

Demasculinization and feminization of male gonads by atrazine: consistent effects across vertebrate classes.

Metabolism and persistence of Atrazine in several field soils with different atrazine application histories.

Atrazine reduces reproduction in fathead minnow

A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians

Early-life exposure to a herbicide has enduring effects on pathogen-induced mortality

Atrazine induces complete feminization and chemical castration in male African clawed frogs

Menstrual cycle characteristics and reproductive hormone levels in women exposed to Atrazine in drinking water.

Urinary biomarkers of prenatal atrazine exposure and adverse birth outcomes in the PELAGIE birth cohort.


Agrochemicals increase trematode infections in a declining amphibian species


Exposure, Postexposure, and Density-Mediated Effects of Atrazine on Amphibians: Breaking Down Net Effects into Their Parts