02
Jul
Case Studies of Cancer Diagnoses Link Pesticides to Cancer Crisis
(Beyond Pesticides, July 2, 2025) An article in The New Lede, entitled Seeking answers to a cancer crisis in Iowa, researchers question if agriculture is to blame, documents case studies of cancer diagnoses linked to chemical-intensive agriculture. Current national cancer rates, according to the American Cancer Society, show that two million new cancer cases are projected to occur during 2025 in the U.S. Additional research predicts 618,120 cancer deaths this year as well, highlighting a crisis of great concern.
A wide body of science links increased cancer risks with exposure to agricultural chemicals, including petrochemical pesticides and synthetic fertilizers. Previous coverage from Beyond Pesticides showcases the disproportionate health risks to farmworkers and their families, as well as those living near agricultural fields, associated with exposure to harmful toxicants. Recent research ties pesticide use to cancer diagnoses among farmer populations through a literature review of clinical trials, as well as epidemiologic, case-control, and experimental studies, from not only the U.S. but Brazil, India, France, Egypt, Columbia, Ecuador, Mexico, Italy, and Spain. (See Daily News here.)
Additional risks for children, as reported in a study in GeoHealth, are noted in Nebraska as exposure to agricultural mixtures show statistically significant positive associations with pediatric cancer, specifically brain and central nervous system (CNS) cancers and leukemia. Scientific literature has also analyzed the mechanisms in which pesticides can impact cancer development. A study in Environmental Sciences Europe finds that the weed killer glyphosate persists in bones before reentering the bloodstream. The mechanisms in which glyphosate interacts with important cells for development, called hematopoietic stem cells (HSCs), and breaks and rearranges DNA offer a possible explanation for the heightened risk of cancer, specifically blood cancers like non-Hodgkin lymphoma (NHL), myeloma, and leukemia.
The New Lede article captures the experiences of individuals in Iowa on “the rising rates of cancer plaguing the state,†with a call for an investigation of “potential environmental causes for what some call a cancer ‘crisis.’†Through both personal stories of cancer patients with no other known risk factors aside from agricultural exposure, as well as comments from community members a listening session held in Indianola, Iowa, the article highlights not only the pervasiveness of cancer but the heightened risks of living in heavily farmed areas. At the listening session, “[T]he moderator asked attendees to raise their hands if they had experienced cancer personally or through someone close to them. Everyone raised a hand.â€
A study published last year in Frontiers in Cancer Control and Society supports the Iowa experience with a finding that agricultural pesticide use “has a significant impact on…all cancers, bladder cancer, colon cancer, leukemia, lung cancer, non-Hodgkin lymphoma, and pancreatic cancer…and these associations are more evident in regions with heavy agricultural productivity.†For all cancers, the highest number of cases per year correlates strongly with the highest pesticide usage, with the Midwest—Iowa, Illinois, Indiana, Ohio, and Nebraska—seeing more than 150,000 additional cases annually.
As a farm state, Iowa represents an area in which heightened exposure to agricultural chemicals occurs with subsequent health and environmental effects. “With nearly 87,000 farms, the state ranks first not only for corn production but also for pork and egg production, and is within the top five states for growing soybeans and raising cattle,†The New Lede article shares. They continue, “Of Iowa’s 35.7 million acres of total land, roughly 31 million is devoted to farming.â€Â
The article also raises concern about specific pesticides, including glyphosate, and PFAS (including fluorinated pesticides), for which there is a long history linked to a wide range of diseases. It states: “PFAS are pervasive globally, and one emerging concern has been PFAS contamination of sewage sludge spread on farm fields as fertilizer. Earlier this year, the Environmental Protection Agency (EPA) warned of elevated cancer risks related to such contaminated farm fertilizer.†(See additional Daily News coverage of PFAS here.)
Another article in The New Lede ties glyphosate to cancer, referencing a study entitled “Carcinogenic effects of long-term exposure from prenatal life to glyphosate and glyphosate-based herbicides in Sprague–Dawley rats.†In describing the research, the article finds:
“A new long-term animal study of the widely used weed killer glyphosate find fresh evidence that the herbicide, introduced by Monsanto in the 1970s, causes multiple types of cancer, and may do so at doses considered safe by regulators.
The results of the two-year study, which were published June 10 in the journal Environmental Health, add to an ongoing global debate over the safety of the pesticide, which is commonly used by farmers to kill weeds in fields and pastures. The chemical is also used widely to manage weeds on golf courses, in parks and playgrounds, and in forestry management.
 ‘Our study provides solid and independent scientific evidence of the carcinogenicity of glyphosate and glyphosate-based herbicides,’ said Daniele Mandrioli, director of the Cesare Maltoni Cancer Research Center of the Ramazzini Institute in Italy. Mandrioli is the principal investigator for the study.â€
This study is the latest to contribute to the mounting evidence of glyphosate’s negative health effects, which Beyond Pesticides and many other organizations consider a poster child for the broken regulatory system that allows toxic pesticides to harm health and the environment.
In the Daily News, U.S. Policy Allows Cancer-Causing Pesticide Use Even Though It Is Not Needed to Grow Food and Manage Land, the history and current status of the regulation of food safety in the U.S. is discussed, showcasing the system as a rickety structure built over a century with unpredictable and often contradictory additions, extensions, remodels, and tear-downs. Beyond Pesticides advocates for a regulatory process that requires the incorporation of the vast body of scientific evidence that pesticides do far more harm than good, and that organic regenerative agriculture is the surest path to human and ecological health.
EPA regulates pesticides under the 1947 Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), to which Congress mandated a major revision with the Food Quality Protection Act (FQPA) in 1996—which repealed the Delaney Clause with the codification of risk assessment protocol that allows for uncertainty, ignores preexisting health conditions and vulnerabilities, fails to evaluate chemical mixtures and synergistic effects, and establishes levels of acceptable harm. The Delaney Clause required the banning of chemical additives in food that cause cancer in humans or animals: If a substance was carcinogenic, no level of it would be tolerated in processed food. There was no acceptable threshold below which safety could be assumed. (See more on regulatory deficiencies here and here.)
There is strong evidence that pesticides lead to cancer via upstream mechanisms such as immune inhibition, hormonal derangement, and inflammation that are also common to other health disorders. Health advocates argue that a new approach must address the reality that these mechanisms predispose physiological systems to become disordered, and that averting these dangers would provide a multitude of positive outcomes across the disease spectrum.
With the availability of safer alternatives to toxic chemicals, whether in agriculture, parks, homes, or gardens, the allowance of substances with documented harm to health and the environment is unreasonable. Organic methods are proven to provide numerous health benefits, as well as more nutritious food, that can both protect and enhance biodiversity and mitigate the effects of climate change.
To learn more about organic land management and the benefits, see here and here. Take action to advance the organic movement and contribute your voice to the holistic, systems-based solution that protects the health of all.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Gillam, C. (2025) Seeking answers to a cancer crisis in Iowa, researchers question if agriculture is to blame, The New Lede. Available at: https://www.thenewlede.org/2025/06/seeking-answers-to-a-cancer-crisis-in-iowa-researchers-question-if-agriculture-is-to-blame/.
