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New research finds 485 chemicals in US pesticide products linked to breast cancer

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Cite

Perkins, T. (2026, September 26). New research finds 485 chemicals in US pesticide products linked to breast cancer. The Guardian. https://www.theguardian.com/us-news/2026/sep/26/breast-cancer-us-pesticide-products

Dated when The Aporia collected the article, usually within hours of publication. Check the original for its exact date and byline.

The Guardian · collected 2026-09-26 · by Tom Perkins

Quick Summary

New research published in Environmental Health Perspectives identifies 485 chemicals used in US pesticides linked to breast cancer. The study highlights regulatory gaps, as only individual ingredient safety is assessed by the EPA rather than entire pesticide formulas. These chemicals are found not just in crop treatments but also in household products like lice treatments and lawn fertilizers. With breast cancer incidence rates increasing, particularly among younger women, the findings raise concerns about widespread exposure to these unregulated inert ingredients.
Written by AI on 2026-09-26, from this article's own text only (the story summary below draws on all the coverage).

AI analysis

Story summary

New research published in Environmental Health Perspectives has identified 485 chemicals used in US pesticide products linked to breast cancer, raising concerns about the safety of food and other consumer goods amid rising early onset breast cancer rates globally. The study, co-authored by Jenny Kay from the Silent Spring Institute, highlights deficiencies in how pesticides are regulated in the US. Unlike European standards, the Environmental Protection Agency (EPA) only evaluates individual health risks of pesticide ingredients rather than considering the cumulative effects of entire formulas or multiple pesticide exposures. These chemicals are found not just in crop treatments but also in products like lice treatments for children, home lawn fertilizers, and flea and tick treatments.

Written for “Pesticides Linked To Cancer” on 2026-11-02, grounded in this article and the 0 other(s) covering the same event.

Story

📰 Pesticides Linked To Cancer
Health · 1 article(s) covering the same event.

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How this article was measured signals, leaning charts, publisher record, byline, topics and claims

Signals How these are calculated →

Claims extracted
31
sentences that state something as happening or true
Uncertain
6%
2 of 31 hedged ("reportedly", "may", "according to")
Leaning
Leans strongly left
of the writing, not the subject · beta estimate
Publisher signals
66/100
The Guardian's corrections and hedging, across everything collected from it. Not a measure of accuracy.
Outlets on this story
1
Health
Same framing elsewhere
1
articles that frame the event the way this one does
Analyzed 2026-09-26 · how these are computed

How this is being covered How these are calculated →

Article leaning vs. publisher reliability
Source leaning vs. consistency

Publisher

The Guardian · 1894 article(s) · 6 correction(s) detected
Running correction rate · 6 correction(s)

Who wrote this

Tom Perkins
7 article(s) here · 1 carrying a prediction
🔮 He said the environmental groups screen for potential county or industry employees, and greet people who they do not know, so they would have noticed Vital’s name had it been displayed.
🔮 The defense department has now granted SpaceX access to its most precise data on potential collisions among satellites and other space objects, which will give Musk’s companies an advantage over competition that offers a similar service.
🔮 It now reads: “Quantities of Pfoa may be produced, imported, and used by companies …
🔮 The overall project would have released enough pollution to trigger a major review.
🔮 The study identified 16 pesticides that are not listed under Prop 65, and the authors say adding these chemicals could discourage companies from using them.
🔮 “[Companies] are permitted to submit mitigation ideas that preserve their product’s utility, and EPA also will independently develop its own proposed mitigations.
🔮 “There is some amount of urgency here, and my hope is that this might accelerate the conversations that the government might have about providing [Pfas health monitoring] to all veterans,” said Christian Hoover , a study co-author and a pre-doctoral fellow in epidemiology at Brown’s School of Public Health.
Also by Tom Perkins
Nothing else under this byline is closely related to this article, so these are simply their most recent.
All 7 articles by Tom Perkins →

Topics

EPA Environmental Health Perspectives Silent Spring Institute The Environmental Protection Agency the American Chemical Society

Subjects

EPA ORG · 8× Kay PERSON · 4× the Silent Spring Institute ORG · 2× Environmental Health Perspectives ORG · 1× Jenny Kay PERSON · 1× Silent Spring Institute ORG · 1× The Environmental Protection Agency ORG · 1× the American Cancer Society ORG · 1× the American Chemical Society ORG · 1× the National Health and Nutrition Examination Survey ORG · 1×

Narrative

New research has identified at least 485 chemicals used in US pesticide products that are linked to breast cancer, raising questions about the safety of food and other products at a time when early onset breast cancer rates are surging worldwide.
framing: assertive · carried by 1 article(s) · first seen 2026-09-26
🔮 The study identified 16 pesticides that are not listed under Prop 65, and the authors say adding these chemicals could discourage companies from using them.

Claims (31 extracted, 2 hedged)

New research has identified at least 485 chemicals used in US pesticide products that are linked to breast cancer, raising questions about the safety of food and other products at a time when early onset breast cancer rates are surging worldwide. asserted
rates → identify → time
The new peer-reviewed paper, published in Environmental Health Perspectives, a top journal from the American Chemical Society, highlights what public health advocates say are a range of deficiencies in how US pesticides are regulated. asserted
pesticides → review → deficiencies
The review includes active pesticide ingredients, but also hundreds of so-called “inert”, or inactive, ingredients that typically do not undergo a thorough safety review. asserted
that → include → review
The Environmental Protection Agency only considers each pesticide ingredient’s individual health risks, and does not consider the entire pesticide formula, or exposure to multiple pesticides. asserted
Agency → consider → pesticides
The chemicals are not just found in pesticides used on crops, but also in lice treatments applied to children’s scalps, home lawn fertilizers, and flea and tick treatments. asserted
chemicals → find → scalps
“Adding these exposures up gets pretty consequential and concerning,” said Jenny Kay, a report co-author with the Silent Spring Institute non-profit. asserted
Kay → add → profit
“We wanted to bring more attention to the pesticides in different products.” asserted
We → want → products
Beside skin cancers, breast cancer is the most commonly diagnosed cancer in the US. asserted
cancer → diagnose → US
Incidence rates for breast cancer have notably increased by 1% per year, according to the American Cancer Society, and that rise has actually been slightly faster in women younger than 50 (1.4%). uncertain
rise → increase → 50
Pesticide use has also increased in recent years, as federal health data via the National Health and Nutrition Examination Survey (NHANES) shows 84 of these specific breast cancer-linked chemicals are present in the general population. asserted
84 → increase → population
But that number, scientists say, is an undercount because it does not track most of the compounds the Silent Spring Institute identified. asserted
Institute → say → compounds
The pesticide review is part of a broader systematic effort by the institute to identify where in the economy, and across everyday life, people are exposed to breast cancer-linked chemicals. asserted
people → identify → chemicals
It identified about 500 in common consumer goods, and 462 in drinking water. asserted
It → identify → water
Only about 145 of the pesticide chemicals identified were registered with the EPA as active ingredients, meaning that the chemical industry is either using the inert status to avoid health scrutiny, or exploiting other loopholes. asserted
industry → identify → loopholes
Inactive, or inert, ingredients are usually added as surfactants or penetrating agents that help disperse the active ingredients or make them more absorbable. asserted
them → add → ingredients
About 4,000 inert ingredients are approved for use by the EPA, among them Pfas “forever chemicals”. asserted
ingredients → approve → them
They are often added to make the pesticide more toxic to a living organism. asserted
pesticide → add → organism
“They are not biologically inert, they are just called inert because they do not target the pest,” Kay said. asserted
Kay → call → pest
In other words, the body does not distinguish between inert and active ingredients, and inactive substances are no less of a danger to human health. asserted
substances → distinguish → health
“It is a regulatory blind spot,” Kay said. asserted
Kay → say → ?
The EPA in 2023 rejected a legal petition to start more stringently reviewing inert ingredients. asserted
EPA → reject → ingredients
Kay said another problem lies in hormone-disrupting chemicals causing disease at lower levels of exposure, but not higher. asserted
problem → say → exposure
This “non-monotonic dose response” has led the EPA to dismiss some chemicals’ risks, and ignore that they can cause cancer at low levels. asserted
they → lead → levels
The pesticide office in particular has been viewed as being heavily infiltrated by industry, and subjected to its influence. asserted
office → view → influence
“I’m not in the head of EPA scientists, but I do worry a lot about industry pressure and the revolving door between EPA and industry employees because all of that factors into the way the EPA considers and regulates chemicals,” Kay said. asserted
Kay → ’m → chemicals
The Silent Spring Institute called for an expansion of California’s Proposition 65, which requires warnings for chemicals known to cause cancer or reproductive harm. asserted
which → call → cancer
The study identified 16 pesticides that are not listed under Prop 65, and the authors say adding these chemicals could discourage companies from using them. uncertain
adding → identify → them
People can protect themselves by buying organic produce, or products that have not been treated with pesticides, as much as possible. asserted
that → protect → pesticides
If that’s not possible, Consumer Reports has an easy-to-use guide on which fruits and vegetables typically have the highest levels of pesticide residues on them. asserted
fruits → ’ → them
A recent report found about 25% of the nation’s water intake and around 675,000 wells draw water contaminated with dangerous levels of atrazine, a hormone disrupting chemical linked to breast cancer. asserted
wells → find → cancer
Water-filtration systems can filter pesticides from water, and though no system is perfect, activated carbon and reverse osmosis generally do the best job. asserted
carbon → filter → job
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