The Great Glyphosate Debate

Posted Monday, Oct 24, 2016

What is Glyphosate? 

    Glyphosate is a broad-spectrum herbicide used to kill weeds that compete with crops. It was developed by Monsanto in 1970 and brought onto the market a few years later under the name Roundup. In the 1990s, Monsanto revealed genetically-engineered crops that were unaffected by glyphosate, allowing farmers to kill weeds without killing crops. The use of glyphosate has steadily increased since, and today it is the most used herbicide in the world. Beyond Roundup, glyphosate is also found in several agricultural, forestry, and residential herbicides. 

 Why Care About Glyphosate?

    In March 2015, the World Health Organization (WHO) announced that glyphosate is “probably carcinogenic to humans.” 1

    Because it is the most widely used herbicide in the world, glyphosate is something we are increasingly in contact with. It has, predictably, become a pervasive chemical in much of our food. Traces of glyphosate have been found in honey, flour, beef, GM soybeans, and infant formula.

    What is in our food, is certainly in our bodies. The chemical has been detected in drinking water, urine, and breast milk in independent studies throughout North America and Europe. 

    Through The Detox Project we were able to conduct our own glyphosate test. The Detox Project tests for the presence of glyphosate in urine and water.

    We wanted to determine if eating a predominantly local and organic diet lowers ones exposure to glyphosate. We had the urine of two subjects tested. Both were 29-year-old men, born and raised in Calgary. One subject had a predominantly whole food, organic diet, and the other a conventional diet. 

    The results, seen below, are a resounding ‘yes:’ a diet consisting of pesticide & herbicide free organic foods limits ones exposure to glyphosate.

    On the left, are the results for subject A - a conventional diet, and raised in an urban environment with little-to-no contact with agricultural settings. His urine was found to have 2.6 parts per billion (ppb), just below the Canadian average of 2.8ppb. 

    In contrast, the results for subject B are on the right - a primarily organic or locally produced, spray-free diet. He was also raised in an urban environment. His urine was found to have less than the lower limit of quantification - meaning it was lower than 0.5ppb, and therefore could not be measured.

    Tap water from the Sunnyside Natural Market staff room was also found to be less than the lower limit of quantification for water, or less than 0.01ppb.

How Dangerous is Glyphosate?  

    Concerns over the safety of glyphosate are hotly contested in scientific and political communities - as one would expect from a multi-million dollar issue that effects a billion dollar industry.

    Monsanto continues to insist glyphosate poses no threat to human or environmental health while providing studies to back their claim. It should be pointed out this is a company with a laundry list of successful lawsuits filed against them over health and environmental issues as a result of their products - including Alachlor, the second most used herbicide in the world. They have also (on more than one occasion) knowingly submitted flawed scientific data to the Environmental Protection Agency (EPA).

    Just last month, the EPA announced their own position: glyphosate likely does not cause cancer. This announcement was largely influenced by an independent study released in the summer which aimed to critique the findings that led to WHO’s assertion that glyphosate was probably carcinogenic.  The study can be found here, and is currently being cited by many as successful counter-evidence to WHO’s conclusion. 

    The use of the word ‘independent’ is highly suspect, however. Skip to the end of the study and you’ll find the “Declaration of interest”, where it is revealed that the panel of independents was put together by the scientific consultancy Intertek. The study then goes on to state that “funding for this evaluation was provided to Intertek by the Monsanto Company.”

    There have been several studies over the years that suggest glyphosate is not as safe as Monsanto has claimed it to be:

  • In the 1980’s, the EPA was involved in a dispute with Monsanto over the findings of tumours in mice exposed to glyphosate. Monsanto’s claim that the tumours were not a result of glyphosate were deemed by the EPA to be “not… convincing.” 2
  • A 1995 study of Ontario farmers linked glyphosate use with an increase of miscarriages and premature births. 3
  • A study in 2010 found glyphosate induced cancer in mice. 4
  • In 2013 a study found glyphosate increased the proliferation of estrogen-dependent breast cancer cells. 5
  • In 2014 a study found when Roundup was administered to rats through drinking water, severe organ damage and increased mammary tumours were found over a 2-year period of exposure. The water was diluted with a level of Roundup half of what is deemed safe in the EU, and 14,000 times lower than permitted in drinking water in the United States. 6
  • In the spring of this year a group of 94 scientists came out in support of WHO’s statement that glyphosate was probably carcinogenic, releasing a critical assessment on how information is being used to suggest otherwise. 7

    This is by no means an exhaustive list.

    To put the findings of our own test into perspective, here are a few studies that used specific quantities of glyphosate:

  • 0.1ppb was found to alter the gene function of over 4,000 genes in the livers and kidneys of rats. 8
  • 10ppb had toxic effects on the livers of fish. 9

    The dramatic increase in the application of glyphosate over the 20 years to 2012, can be seen in the maps below. A similar trend has occurred in Canada.

Governments Are Beginning to Approach Glyphosate With Caution

    While Health Canada believes that current levels of glyphosate use in the agricultural industry are safe, they did see the need to re-label RoundUp with clearer warnings of its potential health risks. This new labelling rolled out in 2015, and recommended a 12-hour restricted entry period after agricultural use, and a statement indicating it should only be applied when the “potential drift to residential or populated areas is minimal.” 10

    In the U.S., the Food and Drug Administration began routine testing for glyphosate residue in February of this year.11 This is the first time such testing has been done by a federal agency in the U.S.

    Meanwhile in Europe, the EU has been unable to come to an agreement on whether to ban the sale of glyphosate entirely.12 Many governments within the EU have cited environmental and health concerns as a reason to ban the sale of any herbicides containing the chemical, but the body as a whole has failed to come to an agreement.

How to Avoid Glyphosate

    As the results of our test show, you can minimize the amount of glyphosate you come in contact with by eating organic, or ensuring the farms you are getting your food from a trusted, spray-free, farm. We know and trust all the farmers we deal with.

    A study of a Swedish family found that during a period of eating conventional food, their urine contained a number of “insecticides, fungicides and plant growth regulators.” After just two weeks of an organic-only diet the results were very different. Researchers noticed a drop in pesticides after only one day, and after the full two weeks there was “very little evidence of the pesticides and other compounds in their follow up urine samples.” It’s never too late to make the change.

The Big Picture 

    We chose to discuss Glyphosate as a danger because of the massive quantities of it that are being used in the world, and through our simple test have shown that it affects Calgarians. The dangers of pesticides are not just a Glyphosate issue, however. We point the interested reader to an excellent summary of numerous studies put together in 2015 that outlines the many pesticides used in agriculture, and why we should be concerned of the potential negative effects they are causing to health. We leave you with an excerpt from those conclusions:

    "Many synthetic pesticides used in agriculture are persistent and pervasive in the environment and, as a result, we are exposed to a cocktail of chemicals through the food we consume and the environment in which we live. Evidence suggests that much of this exposure is presented as multiple mixtures of chemicals, the toxic effect of which are unknown, particularly over longer time scales (Reffstrup et al. 2010). In some cases these substances can interact such that mixtures may have unpredictable and higher toxicities than the individual components themselves. Whilst attempts have been made to describe the toxicity of these interactions, there are no accepted international guidelines in evaluating such risks. Pesticides are, of course, not the only hazardous chemicals to which our bodies are exposed on a daily basis.

    There is, therefore, a compelling case and an urgent need to reduce and, wherever possible, avoid human exposures to hazardous chemicals. In the case of agrochemicals, this will require us to fundamentally rethink and change our farming systems to eliminate our exposure to synthetic pesticides and protect the health not only of particularly highly exposed and/or vulnerable groups, such as agricultural workers and children, but also the general population and wild ecosystems... "


Cressey, Daniel. "Widely Used Herbicide Linked to Cancer." Scientific American

Dykstra W. Memorandum from William Dykstra to Robert J. Taylor: Subject: Glyphosate – EPA Registration Nos. 524–318 and 524–333 – Historical Control Data for Mouse Kidney Tumours. Washington, DC: US Environmental Protection Agency (EPA); 1989.

Savitz, D.A. et al. 1997. "Male pesticide exposure and pregnancy outcome." Am. J. Epidemiol. 146: 1025-1036.

4 George J, Prasad S, Mahmood Z, Shukla Y. Studies on glyphosate-induced carcinogenicity in mouse skin: A proteomic approach. J Proteomics. 2010;73:951-964.

Thongprakaisang S, Thiantanawat A, Rangkadilok N, Suriyo T, Satayavivad J. "Glyphosate induces human breast cancer cells growth via estrogen receptors." Food Chem Toxicol

Séralini G-E, Clair E, Mesnage R, et al. Republished study: "long-term toxicity of a Roundup herbicide and a Roundup-tolerant genetically modified maize." Environ Sci Eur. 2014;26(14)

Portier, Christoper J., et al. "Differences in the carcinogenic evaluation of glyphosate between the International Agency for Research on Cancer (IARC) and the European Food Safety Authority (EFSA)."Journal of Epidemiology & Community Health. 2015. 

Mesnage, Robin, et al. "Transciptome profile analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure." Environmental Health. August 2015; 14:70. 

Webster, Tamsyn M Uren. "Global transciptomic profiling demonstrates induction of oxidative stress and of compensatory cellular stress responses in brown trout exposed to glyphosate and Roundup.BMC Genomics. 2015; 16:32. 

10 Levinson King, Robin. "Health Canada looks to re-label weed killer Roundup." Toronto Star. April, 2015. 

1Gillam, Carey. "FDA Finds Monsanto's Weed Killer in U.S. Honey."  Huffington Post. September, 2015. 

12 Steinhauser, Gabriele. "EU Fails to Get Sufficient Majority in Vote to Extend Glyphosate Use.The Wall Street Journal. June, 2016. 




Hailey Carr Posted Oct 24, 2016