The timing of the report aligned with an $80 million lawsuit against Monsanto , which uses glyphosate as the active ingredient in its popular herbicide Roundup. The judge ruled that Monsanto had intentionally withheld information about Roundup's potential harm, but did not make any claims about whether it contributed to the plaintiff's cancer.
On March 19, however, a federal jury ruled that Roundup was a "substantial" contributor to another man's cancer diagnosis in 2015. After using the weed-killer to tend his property for more than two decades, 70-year-old Edwin Hardeman said Roundup caused his non-Hodgkins lymphoma. He is one of thousands of plaintiffs who have filed similar claims against Monsanto, which was recently acquired by Bayer .
But Hardeman's case was focused on the consequences of spraying Roundup not ingesting traces of it.
For its August report, the EWG tested levels of glyphosate in 45 samples of conventionally grown oats and determined that 31 fell below its safety criteria. Ten weeks later, it tested another 28 samples, focusing exclusively on Cheerios and Quaker Oats products, and found that all but two showed harmful levels of glyphosate, according to its measures.
Does glyphosate cause cancer?
While some scientists have backed away from the IARC's findings, others are doubling down.
Alex Lu , an associate professor of environmental exposure biology at Harvard, described the IARC as a "world-renowned and reputable" institution whose findings have benefitted global cancer researchers. Having conducted his own research of pesticides in children's diets, Lu said he believed the EWG's safety measures were relatively conservative and that its threshold "is too high."
"This is especially true for parents buying breakfast cereals for their infants and children," said Lu, who is not affiliated with the EWG, though it has covered his findings in the past.
The EWG considers any cereal with a glyphosate level of more than 160 parts per billion to be unsafe. The legal limit for oats as outlined by the Environmental Protection Agency is 30 parts per million, or 30,000 parts per billion, for adults, making the EWG's threshold nearly 188 times as stringent as the EPA's regulations (though it's common to enforce stricter limits for children).
"Since children have an increased susceptibility to cancer-causing substances, it's standard scientific practice to include a tenfold margin of safety," said Tasha Stoiber, a senior scientist at the EWG.
Are Cheerios safe to eat?
In the wake of the EWG's findings in August, both General Mills and Quaker insisted their products are safe. The companies released statements to Fast Company citing their compliance with Environmental Protection Agency standards.
"Our products are safe and without question they meet regulatory safety levels," General Mills said.
"Once the oats are transported to us, we put them through our rigorous process that thoroughly cleanses them," Quaker said in a statement, adding, "Any levels of glyphosate that may remain are significantly below any regulatory limits."
But it still warrants the question: Are the EPA's standards up to par?
The EWG said in its report this week that "the EPA's standards for pesticides and other chemicals are also heavily influenced by lobbying from industry."
Despite these claims, there's still not enough data to conclusively determine a risk. For this reason, Lu said, people might want to limit their exposure to glyphosate as a precautionary measure.
Those worried about the safety of their breakfast foods should consider what the EWG has to say about individual foods.
Of the 28 new samples, the group found that Quaker Oatmeal Squares cereal showed the highest levels of glyphosate, nearly 18 times as high as its safety threshold.
Other foods that stood out as particularly hazardous by the report's standards included Quaker Overnight Oats and Cheerios' Oat Crunch Cinnamon flavor. But even these foods wouldn't be considered unsafe by the EPA.
As with any scientific study, it's possible that new research could shed light on the EWG's warnings. Even studies that once seemed definitive have been called into question the US Department of Health and Human Services recently determined that after decades of being labeled a carcinogen , a zero-calorie sweetener called saccharin is not thought to cause cancer .
It's also possible that scientists could uncover new safety concerns for crops like wheat, barley, beans, and chickpeas, which are exposed to glyphosate before harvest.
