Cereals contaminated with pesticide causing fertility and development problems?

Story in a flash:

• Cereal products were found contaminated with chlormequat.
• Chlormequat was linked to reproductive and fetal development problems in animal studies.
• Chemical is not allowed for use on food crops in the U.S.
• Nonetheless, chlormequat-treated grains have been cleared for import into the U.S. 
• The EPA now proposes allowing chlormequat for use on food crops, claiming to have found no “unreasonable adverse human health risks.”
• Chemical also found in the urine of 90% of people studied.

Pesticide-tainted breakfast cereals — potential for developmental and fertility problems

Parents may be shocked to learn that popular breakfast cereals and granola bars their children regularly eat could be tainted with chlormequat, a new chemical for Americans, that inhibits plant growth and has been shown to affect fertility and fetal development in animal studies. 

Plant growth regulator okayed for imported grains, not yet for U.S. food crops

In the U.S., the EPA has, so far, only permitted chlormequat, a plant-growth regulator, on ornamental plants grown in greenhouses and nurseries. It is used, however, on wheat, oat, and barley crops grown in the European Union, the United Kingdom, and Canada and, in 2018, the EPA permitted the import of oats, barley, and wheat treated with the pesticide. 

The Environmental Working Group (EWG), in its peer-reviewed study, “A pilot study of chlormequat in food and urine from adults in the United States from 2017 to 2023,” published in the Journal of Exposure Science & Environmental Epidemiology, stated that,

 [i]n the UK and European Union, chlormequat is often the most detected pesticide residue in grains and cereals, as documented by monitoring surveys spanning several years. (Emphasis added.)

USA Today's Mary Walrath-Holdridge, reporting on EWG's study, noted that EWG researchers found chlormequat in organic and non-organic oat and wheat-based foods they tested:

Researchers tested conventional oat-based products purchased in June and August 2022 and May 2023. Of both sets, chlormequat was detected in 92% of the tested products. Organic oat-based products had a lower detection rate of 12.5%.

A sample of conventional wheat-based products tested in February 2023 also found that 22% had traces of chlormequat.

The study authors tested several individual items from a variety of brands for the presence of chlormequat. The chemical was found in several General Mills products, including Cheerios; Quakers Food products including oatmeal, granola bars and Old Fashioned Oats; and some generic store-brand granola and cereals, including Walmart and Target. (Emphasis added.)

The pesticide was also found in the urine of people in the U.S. whom the EWG tested, with the rate and concentration increasing over time:

. . . detection frequencies of 69%, 74%, and 90% for samples collected in 2017, 2018–2022, and 2023, respectively. Chlormequat was detected at low concentrations in samples from 2017 through 2022, with a significant increase in concentrations for samples from 2023.

An earlier Swedish study, noted in the paper, found chlormequat in 100% of the individuals tested and at higher concentrations.

In the below Tweet, Wall Street Silver notes the irony of Kellogg's CEO exhorting families under pressure to eat cereal for supper, even as they have been found tainted with the fertility- and development-impairing chemical.

Animal studies prove serious harm

The EWG noted in its journal article that toxicological effects on animals have been known for at least the past 40 years. Danish pig farmers in the 1980s reported reproductive issues in their animals fed chlormequat-tainted grains:

In the early 1980s, the impacts of chlormequat exposure on reproductive toxicity and fertility were first described by Danish pig farmers who observed reproductive declines in pigs raised on chlormequat treated grains [4]. These observations were later investigated in controlled laboratory experiments on pigs and mice, whereby female pigs fed chlormequat treated grain exhibited disrupted oestrus cycling and difficulty mating compared to animals on a control chlormequat-free diet [4]. Additionally, male mice exposed to chlormequat via diet or drinking water during development exhibited decreased fertilization capacity of sperm in vitro [5]. (Emphases added.)

The EWG paper also pointed to recent studies with rats, demonstrating that the rodents were also adversely affected by the pesticide:

More recent reproductive toxicity studies on chlormequat show delayed onset of puberty, reduced sperm motility, decreased weights of male reproductive organs, and decreased testosterone levels in rats exposed during sensitive windows of development, including during pregnancy and early life [6,7,8]. Developmental toxicity studies also suggest that chlormequat exposure during pregnancy can dysregulate fetal growth and metabolism [9] (Emphases added,)

EWG calls for more testing 

The EWG paper concluded with a call for additional testing to understand the potential harm of this chemical to people, especially during pregnancy:

Given the toxicological concerns associated with chlormequat exposure in animal studies, and widespread exposure to the general population, in European countries, and now also likely in the U.S., monitoring of chlormequat in foods and people, in conjunction with epidemiological and animal studies, is urgently needed to understand the potential health harms of this agricultural chemical at environmentally relevant exposure levels, particularly during pregnancy.

Check back as we examine the EPA's controversial approach to chlormequat.