09
Apr
Ecological and Reproductive Consequences of Endocrine-Disrupting Chemicals in Agriculture Identified
(Beyond Pesticides, April 9, 2026) “The routine use of common pesticides in agriculture is no longer an ethically viable option for sustainable food production,” according to a new review in Reproduction & Fertility by livestock researcher Whitney Payne, Ph.D. candidate, and Kelsey R. Pool, PhD, of the School of Agriculture and Environment at The University of Western Australia. They base their position on the endocrine-disrupting qualities of many pesticides.
The authors describe endocrine-disrupting compounds (EDCs) as “an inescapable feature of modern life” and note that the “farming systems sit at the intersection of animal health, environmental integrity, and food production.” The review stresses the risks that EDCs pose to livestock, which are seriously understudied.
EDCs are introduced to cattle, sheep, chickens, goats, and other mammals via pesticides, plastics, and hormone treatments. Since humans consume livestock, the effects of EDCs on animals are not confined to animals themselves. Animal production systems illustrate how EDCs “can enter diverse food chains and ecosystems from a single source,” the authors write, being introduced by humans for one purpose and returning to affect livestock and humans indirectly through their long-term effects and breakdown products. While regulatory systems typically consider direct and indirect exposure pathways in humans and livestock, the fates of secondary and tertiary metabolites in livestock and the broader ecosystem are barely comprehended.
The review considers the endocrine-disrupting processes of insecticides and herbicides. These chemicals do not remain in their original applied form in the environment or even in the crop or animal receiving them. They affect invertebrates and other vertebrates in the environment, where they are degraded by organismal metabolism, microbial action, and sunlight, with the resulting chemical compounds possibly more potent and persistent than the original chemical.
Livestock are affected both by pesticides directly applied topically or in feed, but grazing livestock also encounter exposures through water and the atmosphere. They may eat plants that have been treated with pesticides or have absorbed them from soils and water. Some pesticides bioaccumulate in animals’ fatty tissues.
This becomes a problem for ensuing levels of consumption, as fatty tissues are mobilized during reproduction and development, and the pesticides contained in them can be transferred to offspring. “This can occur in wildlife, livestock, and humans alike, highlighting the vulnerability and broad impact EDCs can have across species,” the authors write. They cite a 2022 study of cattle and sheep feed comparing the maximum allowable pesticide residue levels for human and animal dietary intake in both European Union and non-EU countries with residues in animal feeds. That study also stressed that the allowed levels for lipophilic pesticides were significantly higher than they should be given their “relatively high toxicity and biotransfer factors.”
While the fearsome and broad toxicity of insecticides can no longer be ignored, herbicides have had the reputation as being far less risky than insecticides for humans because most of them target mechanisms like photosynthesis and amino acid formation. This was the case with glyphosate, which was ushered through EPA registration on the erroneous assumption that the plant metabolic pathway it affects was irrelevant to animals. But there is now significant evidence that many herbicides, such as glyphosate and atrazine, can disrupt hormones and trigger oxidative stress.
Importantly, both herbicides and insecticides can be highly persistent in the environment, particularly soils. The herbicide paraquat, the authors note, has a seven-year half-life in soil. The herbicide atrazine and neonicotinoid thiacloprid have half-lives of a year. Even pesticides with a relatively short half-life, like glyphosate (about 42 days in both soil and water) and permethrin (just over a month in soil) can do plenty of damage at the molecular level; even if a chemical has a short half-life in the environment or inside a plant or animal, it can do damage at the molecular level while it is there, particularly if it is continually reintroduced.
The review cites the limited research showing that pesticides affect livestock reproduction. For example, pre-pubescent female sheep exposed orally to 1 mg/kg/day of glyphosate had fewer eggs in their ovaries. A laboratory study of cattle tissues found that 1 ppm of Roundup disrupted sperm motility and embryo development. The authors suggest that in both grazing environments and feedlots, “chronic glyphosate exposure” may result in impaired fertility both by reduced quality of sperm and eggs and early failure of embryos, thus affecting overall fertility.
Research on carbamates and organophosphates also indicates reproductive harms for livestock. Laboratory studies of bovine cervical tissue show that a carbamate derivative disrupted oxytocin signaling, progesterone secretion, and cervical contractions at a concentration of 1 nanogram per milliliter, a level far lower than rodent studies indicated would affect reproductive function. Goat testes in tissue culture that were directly exposed to organophosphates downregulated genes important in spermatogenesis. Pig eggs and sperm exposed to organophosphates produced reactive oxygen species, which can derail the formation of a blastocyst, the earliest phase of embryo development.
Other pesticides have been even less studied in livestock, but there is evidence that neonicotinoids, triazines and pyrethroids all have reproductive effects that can be expected to disrupt the hormone systems of farm animals. Neonicotinoids are EDCs and promote oxidative stress. Limited studies indicate they harm sperm production and function at exposures livestock are likely to encounter on farms. Atrazine, a notorious chlorinated triazine herbicide, changes the processes that synthesize follicle-stimulating hormone, luteinizing hormone, testosterone, and estradiol. It also increases oxidative stress in the hypothalamus and pituitary glands, which have downstream effects on reproduction.
Pyrethroid insecticides typify a serious and understudied problem, according to the authors: research and regulatory testing have not adequately distinguished between the effects of a parent compound and its second- and third-level metabolites. Pyrethroids mimic thyroid hormones and change reproductive hormone receptors on cells. While they metabolize quickly in mammals, they also accumulate in fats, and, ominously, two pyrethroid metabolites, 3-PBA and DCCA, are 100 times and a thousand times more potent than the parent compound, respectively. These metabolites are associated with degraded sperm quality in humans when detected in urine. The authors point out that pyrethroid metabolites have not yet been detected in the meat of farm animals, likely due to their relatively rapid metabolism in mammals, but this does not mean they have not left damaging effects or harmed the health of the animals themselves.
An important aspect of their analysis is that many pesticides are considered neurotoxicants, but their endocrine-disrupting power is obscured. Organochlorines, organophosphates, neonicotinoids, carbamates, and pyrethroids all cripple insects’ neurological systems. Piperonyl butoxide, a common additive to pesticides in these groups, prevents insects from breaking down insecticides.
The authors’ analysis of acetylcholine demonstrates the problem with the siloing of assumptions about pesticides’ molecular behavior. Acetylcholine is common to every domain of life, including microbes, plants, animals, and fungi. In humans, it is a vital neurotransmitter. Many pesticides inhibit the enzyme acetylcholinesterase, which is why they are considered likely causes of diseases like Alzheimer’s and Parkinson’s. Thus, the pesticides that affect acetylcholine pathways have been considered mainly as neurotoxicants. But acetylcholine is also known to affect reproduction in mammals; it is involved in sperm motility, fertilization, oocyte maturation, and cell differentiation in embryos, and its inhibition produces altered expression of receptors for steroid hormones such as estrogen.
It is an enduring mystery why pesticide manufacturers could assume that compounds affecting such basic processes conserved across whole swaths of the web of life would harm only those organisms humans consider pests. The chemistry and architecture of neurons are very similar in anything that has neurons. As the authors more temperately write, “Their limited species-specificity and potential to cause widespread environmental harm should remain key considerations in insecticide use.”
Taken together, the evidence presented in this review underscores the importance of eliminating pesticides in agriculture. The authors suggest that further study of their effects on reproduction would be an effective way to comprehend pesticides’ overall sublethal effects, which are, after all, likely more consequential than their acute effects. Further, it is not as if a pesticide is applied just once to one species and its influence stops there—the pesticide model is like a boomerang, a circular threat that returns repeatedly to harm human and animal health.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
Ecological and reproductive consequences of endocrine-disrupting chemicals in agricultural systems
Payne & Pool
Reproduction & Fertility 2026
https://raf.bioscientifica.com/view/journals/raf/7/1/RAF-25-0178.xml
Associations Between Endocrine-Disrupting Chemical Exposure and Fertility Outcomes: A Decade of Human Epidemiological Evidence
Tzouma et al
Life 2025
https://www.mdpi.com/2075-1729/15/7/993
Framework for defining pesticide maximum residue levels in feed: applications to cattle and sheep
Li & Fantke
Pest Management Science 2022
https://scijournals.onlinelibrary.wiley.com/doi/10.1002/ps.7241
Pesticide Exposure Again Linked to Neurotoxic Effects in Humans and Wildlife in Comprehensive Review
Beyond Pesticides, March 12, 2026
https://beyondpesticides.org/dailynewsblog/category/chemicals/carbamates/
Study Reinforces Importance of Biodiversity in Agriculture and Ecosystem Health
Beyond Pesticides, November 6th, 2024
https://beyondpesticides.org/dailynewsblog/2025/01/public-urged-to-tell-epa-that-it-is-time-to-stop-killing-biodiversity-with-the-weed-killer-atrazine/
Reinforcing Scientific Findings, Insecticide Permethrin Alters Gut Microbiome, Causing Obesity
Beyond Pesticides, September 5, 2025
https://beyondpesticides.org/dailynewsblog/2025/09/reinforcing-scientific-findings-insecticide permethrin-found-to-alter-gut-microbiome-causing-obesity/
Nothing short of a wholesale collapse will cure what ails us.
April 16th, 2026 at 11:57 am