Science Behind Glyphosate Causing Cancer On Trial

Feb 25, 2019 | Toxic Tort

The first of three federal bellweather trials alleging that Monsanto’s Roundup weedkiller causes cancer is scheduled to get underway this week with seven women and two men seated on the jury. The trial, taking place before United States District Judge Chhabria in San Francisco, California, follows a state court bellweather trial, also held in San Francisco, that resulted in a $289 million verdict against Monsanto (later reduced to $78 million) last year. In the present case, Edwin Hardeman alleges that his use of glyphosate-containing Roundup herbicide over several years to control weeds on his personal property resulted in his development of non-Hodgkin’s lymphoma. Early signals from pre-trial hearing and rulings, though, show that this case is being approached with much more scrutiny by the presiding judge – in doing so, the very science behind whether glyphosate causes cancer is at the forefront of the issues being addressed.

What Is Glyphosate?

Glyphosate is a man-made chemical, first synthesized by a Swiss chemist in 1950. It was independently discovered by scientists at Monsanto in the United States in 1970, when the company asked its scientists to develop an effective herbicide compound for consumers to use as a weed killer. The product was brought to market in 1974 under the brand name Roundup.

It was quickly realized that glyphosate was one of the most effective weed killing agents on the market, as it inhibits photosynthesis in plants, which ensures that plant cells are not able to regenerate, thereby killing the plant that glyphosate is applied to.  Roundup soon became one of the most widely used weed killing agents by consumers for use on residential and commercial properties, by landscaping companies, and the government (primarily for use by groundskeepers at public schools). In the agricultural sector, glyphosate’s use was not so readily adapted, as it was so effective that it killed not only weeds, but the crops themselves. It was not until 1996 with the advent of genetically modified crops that were resistant to glyphosate that the product became widely used on farms. Genetically modified crops led to a 15-fold increase in the use of glyphosate in the agricultural sector. According to the U.S. Environmental Protection Agency (EPA), in 2007, glyphosate was the most used herbicide in the United States agricultural sector, with 180 to 185 million pounds applied, the second-most used in home and garden with 5 to 8 million pounds used, and the U.S. government applied 13 to 15 million pounds in industry and commerce.

Is Glyphosate Harmful To Human Health?

Glyphosate studies have been conducted for years prior to the Johnson verdict in July of 2018. The majority of the initial studies were conducted on rats. For example, one trial in the United Kingdom, in which rats were fed low levels of glysophate throughout their lives, found that the chemical contributed to a higher risk of nonalcoholic fatty liver disease, a condition in which fat accumulates in the liver and contributes to inflammation and scarring of the tissue. Studies have also bee conducted on other mammals, such as rabbits, aquatic fauna, plants, and soil bacteria.

Based on these studies, in 2013 a review of over 1,000 epidemiological studies, animal studies, and in vitro studies were reviewed by the German Institute for Risk Assessment. It found that “no classification and labelling for carcinogenicity is warranted” and did not recommend a carcinogen classification.  The results were given to the European Food and Safety Authority (EFSA) and in November of 2015, the EFSA published its own conclusion of the available studies, stating that glyphosate was “unlikely to pose a carcinogenic hazard to humans.”

In the U.S., in 1993, the Environmental Protection Agency (EPA) studied whether glyphosate was hazardous to human health and concluded that the chemical was not carcinogenic. In its review, the EPA considered a “worst case” dietary risk model of an individual eating a lifetime of food derived entirely from glyphosate-sprayed fields with residues at their maximum levels. This model indicated that no adverse health effects would be expected under such conditions. In 2015, the EPA initiated another review of glyphosate’s toxicity and in 2016 reported that glyphosate is likely not carcinogenic.

However, in March 2015, the World Health Organization’s International Agency for Research on Cancer (IARC) concluded its own analysis of the available epidemiological studies and found that glyphosate , is “probably carcinogenic to humans.” “For the herbicide glyphosate , there was limited evidence of carcinogenicity in humans for non-Hodgkin lymphoma,” the report stated. “The evidence in humans is from studies of exposures, mostly agricultural, in the USA, Canada, and Sweden published since 2001. In addition, there is convincing evidence that glyphosate also can cause cancer in laboratory animals.”

The IARC report was criticized for not considering all of the available literature on glysophate. However, IARC admitted that it disregarded any studies that had any connection to the agricultural industry (e.g., studies funded by the industry). This was in contrast to prior govenment agencies, who considered such studies while adjusting for potential biases. Nevertheless, it was the IARC statement regarding the “probable” carcinogenicity in humans that sparked the glyphosate litigation. The cases were ultimately consolidated on a single docket, where now over a thousand plaintiffs have pending lawsuits alleging that glyphosate in Roundup week killer caused their cancer.

The Dewayne Johnson Case

In the seminal glyphosate case, plaintiff Dewayne Johnson, age 46, alleged that his non-Hodgkins lymphoma was caused by mixing and spraying Roundup as the groundskeeper for a school district in California. Johnson was diagnosed with cancer in 2014. His case was expedited for trial, as his doctors confirmed that he does not have long to live. The trial took four weeks to conclude, during which time jurors heard testimony from statisticians, doctors, public health researchers and epidemiologists who disagreed on whether glyphosate can cause cancer.

The landmark California case concluded after thee days of deliberations in which a 12-member jury found that Monsanto’s Roundup and Ranger Pro weed killing products were unsafe and the primary cause of plaintiff DeWayne Johnson’s rare form of non-Hodgkin’s lymphoma. The jury also found that Monsanto had failed to properly warn customers of the risks associated with using the products and that the company acted with malice, oppression or fraud.

The San Francisco jury, made up of five women and seven men, awarded Johnson $39.25 million in compensatory damages and $250 million in putative damages. The compensatory aspect included $2.25 million in economic loss and $37 million in noneconomic damages, one million for every year of plaintiff’s life lost due to cancer.

Science On Trial In Edwin Hardeman Case

One key difference between the prior state case and the pending federal cases is that the federal trials will be bifurcated, as requested by Monsanto. Judge Chhabria’s ruling granting this request means that the trials will be heard in two phases: causation first and then, if necessary, liability. In phase one, the jurors will be asked whether Roundup caused Hardeman’s cancer. If the jury answers this question affirmatively, phase two will address liability and damages.

The result of this ruling in effect puts at the forefront the very issue of whether glyphosate can cause cancer in humans. A key impact of the bifurcation is that plaintiff’s ability to introduce Monsanto’s alleged attempts to influence regulatory agencies will be limited during phase one. Instead, the jurors will hear primarily about several different scientific studies on which to base their decision. Monsanto will likely emphasize the Environmental Protection Agency statements regarding the ability of glyphosate to be safely used while plaintiff will point to the International Agency for Research on Cancer’s statement that glyphosate is probably carcinogenic.

CMBG3 Law LLC has represented clients in products liability matters, especially with respect to allegedly toxic chemicals. We provide the most current legal advice to our clients by staying on top of developments in science, medicine, and regulations regarding a wide variety of substances and products used by consumers every day. If you have any questions or would like more information, please contact Michaela Lancer (email her or 617-279-8216) or John Gardella (email him or 617-279-8225).


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