You know the rule about headlines – if there is a question in a headline the answer is almost always “no”. This article is no exception.
But the lay media seems to want you to worry (presumably because it’s better for clicks), such as this headline from CBS news, “Pesticide linked to reproductive issues found in Cheerios, Quaker Oats and other oat-based foods.” To be fair, headlines don’t always reflect the full content of an article, but if you read the piece all the way through you just get dueling quotes, no real scientific context.
The pesticide in question is chlormequat, a plant growth inhibitor that limits the height of crop stems, making them easier to harvest and reducing the risk that they will bend over or break. In the US the chemical is allowed for use on ornamental plants but not food crops. However, it is allowed for use on food crops in the European Union, and in 2018 the EPA altered their rules to allow the import of European grains grown using the chemical, such as oats.
The study which is getting all the media attention is by the Environmental Working Group, a group that I think is better describes as an advocacy group rather than an objective scientific group. I have long had a problem with how they present data, and this latest study fits right in with their history. The study is described in the title as a “pilot” study and is rather small, involving only 96 subjects. They found:
Here we report, the presence of chlormequat in urine samples collected from people in the U.S., with detection frequencies of 69%, 74%, and 90% for samples collected in 2017, 2018–2022, and 2023, respectively.
Even though it is a small pilot study, let’s assume their results are accurate. As far at they go, they are not surprising since the US started importing grains grown with the use of chlormequat in 2018. They also tested oat-based products and found:
Food samples purchased in the U.S. from 2022 and 2023 show detectable levels of chlormequat in all but two of 25 conventional oat-based products, with concentrations ranging from non-detectable to 291 µg/kg, indicating a high prevalence of chlormequat in oats. Median levels were similar between samples collected in 2022 and 2023, at 90 and 114 µg/kg respectively. Only one sample out of eight organic oat-based products at detectable chlormequat at 17 µg/kg.
Again, not surprising. The real story here is the way in which this study is being reported to the public, which, in my opinion, reveals the true purpose of the study – to create another round of fearmongering about toxins in our food and shill for the organic food industry.
What’s missing from almost all of the reporting is a couple of important pieces of information. From the study itself, what I consider to be the money quote:
Current chlormequat concentrations in urine from this study and others suggest that individual sample donors were exposed to chlormequat at levels several orders of magnitude below the reference dose (RfD) published by the U.S. EPA (0.05 mg/kg bw/day) and the acceptable daily intake (ADI) value published by the European Food Safety Authority (0.04 mg/kg bw/day).
Several orders of magnitude below accepted safety limits – you notice the safety limits are in the mg (milligrams) and the chlormequat levels are in µg (micrograms). For a 70 kg person, they would need to consume (using the US numbers) 3.5 mg per day of chlormequat. Using the highest concentration above and rounding up to 300 µg/kg, you would need to consume 12 kg of oats every day to reach the lower limit of the safety range.
The authors point out that chlormequat is rapidly removed in the urine, which means that measuring it in urine samples likely means ongoing exposure. But it also means that chlormequat is rapidly removed from the body, so you would have to consume those 12 kg of oats every day. Keep in mind, safety limit are already typically set 1-2 orders of magnitude lower than evidence shows correlates with any negative health outcome.
And yet much of the reporting, as in the CBS article, simply states:
Some studies have shown chlormequat can damage the reproductive system and disrupt fetal growth in animals, a cause for concern as to “whether it could also harm humans,” EWG stated.
These studies are in animals. There is no evidence for a similar effect in humans. As they frequently do in my experience, the EWG is confusing hazard and risk. Toxicology and animal studies tell us about a potential hazard from a substance – it is biologically capable of causing some disruption or harm. But this kind of data does not tell us about risk – does this harm actually happen in humans, and at what exposure level? The EWG cannot point to any data regarding risk, so they fall back once again on a hazard-based argument and an overapplication of the precautionary principle – arguing we need to further study potential harm.
Further research is always welcome, but should we be fearmongering in the meantime? It almost makes it seem like this pilot study, with highly predictable results, was done so that the EWG could raise fears about our food and argue that, in order to be safe, just buy organic. The lay media fell for it. The EWG also opposes legislation in the US to allow use of chlormequat, so this study becomes fodder for that lobbying as well.
In reality, this is all a giant nothing burger. The EWG study actually demonstrated that even with allowing into the US, EU grains grown with the use of chlormequat, exposure levels are still several orders of magnitude below safety levels. This nicely demonstrates there is nothing to worry about, but they have successfully spun the story into the exact opposite.
Note: The math above was corrected from the original.