A chemical called chlormequat is commonly used in agriculture around the world, but it is tightly regulated in the United States. However, a preliminary study by scientists at the Environmental Working Group (EWG) found that the chemical is present in four out of five urine samples collected from people living in the US. It’s not clear what impact this chemical could have on human health, and the authors of the study say more research is needed.
It’s worth noting that the EWG has been criticized in the past for exaggerating the risks of genetically modified foods, promoting an unfounded link between mercury in vaccines and autism, and taking funding from the organic food industry. Despite this, the new paper has passed peer review and has been published in Springer Nature’s Journal of Exposure Science and Environmental Epidemiology, which lends it some scientific credibility.
Chlormequat is a type of plant growth regulator (PGR) that is commonly used in agriculture and horticulture. It’s most commonly used in the form of chlormequat chloride, and is the key ingredient in CCC-720 and Cycocel. Its main function is to limit cell elongation in a plant’s stem, which results in a shorter, sturdier plant. Farmers use chlormequat because plants with strong, truncated stems won’t lean or fall over, making crops easier and cheaper to harvest.
Many countries allow the use of chlormequat in agricultural crops, including Australia, the United Kingdom, Canada, and the European Union. However, in the US, the chemical is banned from use on any food crops, and is only approved for use in growing ornamental plants. Despite this, foods grown with chlormequat are allowed to be imported into the country since a decision by the US Environmental Protection Agency in 2018.
The authors of the new paper are concerned about these regulatory changes and the prevalence of chlormequat in their samples. Their urine samples were from mixed sources, including 21 samples from pregnant women in South Carolina from 2017, 25 samples from Missouri collected from men and women between 2017 and 2022, and 50 samples from men and women in Florida in 2023. They found that the chemical was present in 69 percent of the 2017 samples, 74 percent of samples from 2017-2022, and 90 percent of samples from 2023.
While the concentrations of the chemical were consistent between the 2017 and 2018-2022 groups, the samples from 2023 had significantly higher concentrations. Chlormequat doesn’t stay in the body long, so the authors say the high prevalence could indicate “likely continuous exposure”. However, this theory would need to be tested over time with a larger data set. The small sample sizes and different sources of samples mean it’s not possible to compare trends across the different years and locations.
The authors also found chlormequat in food purchased and tested in 2022 and 2023. It was present in all but two of the 25 oat products tested, and in two of the nine wheat-based products tested.
The effects of chlormequat on human health are not well understood, but some animal studies have found that exposure to levels deemed safe by the WHO can be linked to issues with fertility, puberty, fetal development, and postnatal health. However, other studies report entirely opposite results.
“The ubiquity of this little-studied [plant growth regulator] in people raises alarm bells about how it could potentially cause harm without anyone even knowing they’ve consumed it,” says toxicologist Alexis Temkin from EWG, who led the research.
EWG is urging for further research on the potential health impacts of chlormequat on humans, but lawmakers are relaxing regulations on its use. Last year, the Trump administration raised the permissible amount of chlormequat in imported oats in the US. Currently, the Biden administration is contemplating approving its use in barley, oats, wheat, and triticale grown in the US.
“The federal government has a vital role in ensuring that pesticides are adequately monitored, studied and regulated,” Temkin says. “Yet the EPA continues to abdicate its responsibility to protect children from the potential health harms of toxic chemicals like chlormequat in food.”
This news is a creative derivative product from articles published in famous peer-reviewed journals and Govt reports:
References:
1. Temkin, A.M., Evans, S., Spyropoulos, D.D. et al. A pilot study of chlormequat in food and urine from adults in the United States from 2017 to 2023. J Expo Sci Environ Epidemiol (2024). https://doi.org/10.1038/s41370-024-00643-4
2. EPA. Chlormequat Chloride Interim Registration Review Decision Case Number 7069. Enivronmental Protection Agency. 2022;Docket Number EPA-HQ-OPP-2015-0816.
3. Reynolds SL, Hill AR, Thomas MR, Hamey PY. Occurrence and risks associated with chlormequat residues in a range of foodstuffs in the UK. Food Addit Contam. 2004;21:457–71.
4. EFSA. The 2014 European Union report on pesticide residues in food. EFSA J. 2016;14:4611.
5. Sorensen MT, Danielsen V. Effects of the plant growth regulator, chlormequat, on mammalian fertility. Int J Androl. 2006;29:129–33.
