Weed Killer Chemical and Kids’ Cereals: Toxicity Experts Debate the Risk of Glyphosate
Arms of the World Health Organization and the U.S. Department of Health and Human Services have found that glyphosate is a probable carcinogen. The EPA and Bayer-Monsanto disagree.
Various oat-based products like cereals, trail mixes and snack bars tested positive over the past year for a chemical in a widely used weedkiller that is linked to cancer, according to the Environmental Working Group, an advocacy organization. While several experts say not to panic, they note that a debate exists over how great a risk the chemical poses to consumers.
“I am the parent of a 2 1/2-year-old,” toxicity expert Jamie Alan with Michigan State University told NBC. “I will be letting her finish the Cheerios she has, but will probably buy the organic brand from now on.”
Glyphosate, an active ingredient in Bayer-Monsanto’s Roundup weed killer, has been discovered in several of General Mills’ oat-based cereals and snacks in the most recent of three rounds of testing by the Environmental Working Group. The chemical, which is also found in other herbicide brands, regulates plant growth and hastens crop ripening in broadleaf plants and grasses.
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People can be exposed to glyphosate by breathing it in, eating food treated with it, or absorbing it through the skin.
The Environmental Working Group is a nonprofit with financial links to the organic industry that specializes in research into toxic chemicals and advocates for their removal from food and products. Honey Nut Cheerios Medley Crunch and Cheerios contained more than quadruple a limit devised by the environmental group, one that is not universally accepted.
“This is a big deal on oats,” Christopher Bosso, professor of public policy at Northeastern University, told NBC. “Oats hadn’t been major in residues. They were seen as safe.”
Bosso said he didn’t have a reason not to trust the environmental group’s data, but that “the conversation is what the benchmark is for safe exposure, which is disputed.”
General Mills told NBC that its top priority has been food safety, and that the company “continue[s] to work closely with farmers, our suppliers and conservation organizations to minimize the use of pesticides on the ingredients we use in our foods.”
The Environmental Working Group tested products against a standard of 0.01mg of glyphosate per day, an amount that would allow a consumer to eat about two bowls of Honey Nut Cheerios.
That amount of glyphosate is 7,000 times smaller than a federal level set by the Environmental Protection Agency, which is responsible for creating the legal limits on pesticide residues. It is also 110 times smaller than the "no significant risk level" established by California, on which the environmental group based its initial tests.
Lisa Lefferts, senior scientist for Center for Science in the Public Interest, a food advocacy organization, called the environmental group’s approach “very conservative” because its level is much lower than California and the EPA's.
But she also said that General Mills should take more action.
“General Mills should tell its suppliers not to use glyphosate, or at least, reduce to a minimum the levels of glyphosate and other pesticides getting into foods,” she said.
Arms of the World Health Organization and the U.S. Department of Health and Human Services have found that glyphosate is a probable carcinogen. The EPA disagrees.
"There’s no evidence that glyphosate causes cancer," Alexandra Dunn, an EPA assistant administrator for chemical safety and pollution prevention, told the Des Moines Register in April. "There's no risk to public health from the application of glyphosate."
The EPA’s proposed reference dose — which it defines as “an estimate of daily exposure that would not cause adverse effects throughout a lifetime” — is 1 milligram of glyphosate a day for every kilogram you weigh.
The Environmental Working Group created its limit by starting with a risk exposure level for cancer of 1.1 milligrams a day set by the California Office of Environmental Health and Hazard under the state’s Proposition 65. The environmental group used California’s level — meant to warn consumers of pesticide levels in foods — because it was “based on [California’s] cancer findings,” according to Olga Naidenko, its vice president of science investigations.
California has classified the chemical as a Group 2A carcinogen, which means that there is sufficient evidence that it causes cancer in animals used in experiments and is probably carcinogenic to humans.
“[Glyphosate] is known to the state of California to cause cancer,” said Sam Delson, the deputy director for external and legislative affairs at the Office of Environmental Health and Hazard.
The state’s estimate is that if 100,000 people are exposed to glyphosate in a lifetime, one additional case of cancer would be expected.
In devising its benchmark, the environmental group applied a separate federal law, the Food Quality Protection Act, that requires organizations to “consider the special susceptibility of children to pesticides by using an additional tenfold (10X) safety factor when setting and reassessing tolerances unless adequate data are available to support a different factor.” The EPA does not factor the law into its limit because the agency found that there is “no indication that children are more sensitive to glyphosate.”
Honey Nut Cheerios Medley Crunch, the food found by the environmental group to have the highest levels of glyphosate, contained 833 parts per billion, which is equivalent to 0.83 milligrams per kilogram and below the level that would have required notification in California. In fact, the state categorizes glyphosate as posing “no significant risk” because it is not aware of foods containing amounts of the chemical that exceed its risk level.
In 2015, an agency within the World Health Organization, the International Agency for Research on Cancer, also found that glyphosate is a possible carcinogen. Then, in 2017, a second scientific group, the Agency for Toxic Substances and Disease Registry, a part of the U.S. Department of Health and Human Services, released a study that confirmed and strengthened the cancer agency’s research.
The EPA stands behind findings from other studies that contradict the two agencies’ conclusions.
In April, EPA scientists concluded that there is “no risk to human health from current uses of glyphosate" and "no evidence that glyphosate causes cancer." Earlier, in 1993, EPA listed the chemical at the second lowest of four levels of toxicity.
The agency is currently reevaluating the chemical under its pesticide registration review program, as it is required to do for all registered pesticides at least every 15 years.
Research conducted by a scientific journal, Environmental Sciences Europe, found that the conclusions reached by EPA and the International Agency for Research on Cancer differed because the EPA relied mainly on studies conducted in-house by Monsanto or contracted by EPA with an outside lab, the author, Charles Benbrook, told NBC. Ninety-nine percent of these studies showed no connection between glyphosate and cancer because the agency "largely ignored" studies focused on groups exposed to high amounts of glyphosate, according to Benbrook, who was also an expert witness for the plaintiffs in recent lawsuits against Monsanto.
The cancer agency evaluated mostly peer-reviewed studies, 70% of which showed a link between glyphosate and cancer. It also encompassed a wider range of data, while the EPA invested "much less effort" in ensuring that their assessments were based on "accurate exposure and toxicological data,” according to Benbrook’s findings.
The EPA told NBC that the agency “considered a significantly more extensive and relevant dataset” than the International Agency for Research on Cancer.
Lefferts, of the Center for Science in the Public Interest, argues that the cancer agency is the best authority. She told NBC that she thinks the EPA's level is "too low."
“Right away, I think the EPA standard has a problem because it [says glyphosate] doesn't cause cancer,” Lefferts said. "This is more than just a correlation. Glyphosate causes cancer in animals and it is likely that glyphosate causes cancer in humans.”
On June 14, Bayer announced its plans to invest $5.6 billion over the next decade to develop “additional methods to combat weeds.”
The news comes after thousands of recent lawsuits alleged that glyphosate is causing cancer. Many of those who sued were exposed to glyphosate directly, absorbing or breathing in the chemical while spraying it on crops. This type of exposure poses a greater risk for cancer because the exposure amount is higher than it is in foods, the EPA told NBC. The EPA has set a level of 30 milligrams per kilogram of food as the maximum amount of glyphosate that is allowed to remain in or on food. That measurement is separate from its reference dose and is meant to ensure that the pesticide is used according to label directions.
Most recently on May 13, jurors awarded more than $2 billion to a California couple who say the Roundup they used on their land caused their non-Hodgkin’s lymphoma.
Bayer-Monsanto insists that Roundup is not linked to cancer, and is appealing that verdict and others.
Bayer has also petitioned the EPA to raise its maximum legal residue levels for glyphosate, which the EPA has increased by 300% since 1993.
The EPA said that its maximum residue levels were changed to “harmonize” with Codex Maximum Residue Levels, which is a set of international food standards, guidelines and codes of practice. The agency told NBC it “found no risks of concern in the current dietary risk assessment assuming the maximum-allowable residues on cereal grains.”
The EPA arrived at this conclusion relying partly on a paper published in 2000, which assessed the risk of glyphosate, that Monsanto scientist William Heydens said the company ghost-wrote. The claim was made in an email that was unsealed by a federal judge in California and is among the documents introduced in the court cases against Monsanto by those suing the company.
In the 2015 email, Heydens proposed a "less expensive/more palatable approach" in which Monsanto would use the same method as the 2000 paper and “ghost-write” sections of a new scientific publication.
Heydens said an option would be to add the names of some scientists in the field, Helmut Greim, Larry Kier or David Kirkland, to the publication and then "we ghost-write the Exposure Tox & Genotox sections. But we would be keeping the cost down by us doing the writing and they would just edit & sign their names so to speak,” Heydens wrote. “Recall that is how we handled Williams Kroes & Munro, 2000."
Monsanto insists that the company did not ghostwrite the Gary M. Williams, Richard André Kroes, and Ian Munro glyphosate paper, which concluded that the chemical does not pose a health risk to humans. The court documents indicate Heydens did review and edit parts of the 2000 paper; Monsanto says the editing was minor. The EPA used the Williams publication as a reference in its own paper to conclude that the "strongest support" for classification of glyphosate is "not likely to be carcinogenic to humans."
Lefferts of the Center for Science in the Public Interest said that the risk from glyphosate in cereal is small, but that there is no reason to eat foods that contain the chemical.
“We take drugs that have side effects because we think they will cure a condition we have. When we’re eating food, it’s supposed to be nourishing, good for us,” she said. “What’s the good for us putting up with cancer-causing substances? There is no benefit directly.”
Northeastern University's Bosso agrees that the impact of eating a bowl of cereal is probably very little, but that he eats organic to avoid exposure to chemicals.
“I am afraid of glyphosate,” he said.
A growing number of countries, cities, and towns are placing bans or restrictions on glyphosate use. Currently, 29 countries have joined this effort, with Austria announcing in June its plans to ban glyphosate within the year. The United States has yet to place a ban on glyphosate.
The glyphosate findings point to a larger issue in the food industry when it comes to chemicals.
“The [Environmental Working Group] report is putting pressure on the industry to switch to organics and not use glyphosate,” Bosso said. “[But] the bigger conversation is the fact that, in general, there are too many chemicals out there in food and in life.”