by James Lyons-Weiler, PhD, Popular Rationalism, ©2025
(Dec. 4, 2025) — They’re spraying PFAS on our food, and the public has no idea.
PFAS—per- and polyfluoroalkyl substances—are synthetic chemicals engineered to resist heat, oil, and water. Their carbon-fluorine bonds, among the strongest in chemistry, make them incredibly stable and essentially non-degradable in nature. Developed in the 1940s, PFAS found early use in industrial applications, firefighting foams, and consumer products like nonstick cookware, waterproof fabrics, and food packaging. But in recent decades, they’ve entered an entirely new arena: agriculture.
PFAS now reach food crops through four primary routes: as active ingredients in pesticides, as unlabeled co-formulants or impurities in pesticide mixtures, as leachates from fluorinated containers, and via biosolids (processed sewage sludge) applied to soil as fertilizer. Each of these vectors has been confirmed in the scientific literature. And yet, none of them are disclosed to consumers—and few are understood even by farmers themselves.
In California, the state’s comprehensive pesticide reporting system shows that more than 15 million pounds of PFAS-containing pesticides were sprayed between 2018 and 2023. These included dozens of registered active ingredients used on almonds, tomatoes, grapes, pistachios, and alfalfa—commodities that make their way into baby food, school lunches, and livestock feed. These chemicals aren’t legacy contaminants drifting in from past manufacturing; they’re new PFAS chemistries, registered and sprayed intentionally. In 2025, EPA approved two more: cyclobutrifluram and isocycloseram, which are now allowed on leafy greens, peas, citrus, cottonseed, and more. Both belong to chemical families that degrade into smaller PFAS over time.
But most pesticide users—and the public—remain unaware that PFAS are involved at all. That’s because PFAS can be present as so-called “inert” ingredients in pesticide formulations. These aren’t disclosed on product labels and are often shielded under confidential business information protections. In one study published in Journal of Hazardous Materials Letters, researchers found PFOS, a toxic and globally restricted PFAS, in six of ten common agricultural insecticides at concentrations between 3.9 and 19.2 mg/kg. Soil and plant samples taken from fields where these insecticides were used also tested positive for PFAS.
Still more PFAS reach food crops through biosolids. These are the solids left over from wastewater treatment, marketed as free or low-cost fertilizer. Because PFAS survive the treatment process intact, they concentrate in biosolids. Farmers apply them to fields unaware they are seeding the soil with persistent organic pollutants. Multiple studies—including field trials on lettuce, tomatoes, and corn—confirm that PFAS are taken up by plants from these soils. Short-chain PFAS like PFBA and PFPeA, which are highly mobile, accumulate especially in leafy tissues. Even single applications of industrially impacted biosolids can lead to measurable contamination of plants and runoff.
EPA’s biosolids regulations do not yet include enforceable limits for PFAS, though states like Maine have begun to act independently. In 2022, Maine banned all land application of biosolids after PFAS were detected in soil, groundwater, milk, and meat from affected farms.
Why does this matter? Because PFAS are toxic at vanishingly small doses and build up over time. CDC biomonitoring shows that over 97% of Americans have detectable PFAS in their blood. Studies confirm PFAS in umbilical cord blood, placenta, and breast milk, meaning exposures begin in utero and continue through infancy.
The most consistently demonstrated health effect of PFAS is immune suppression. The National Toxicology Program classifies PFOS and PFOA as presumed human immune hazards. In a landmark study published in JAMA, researchers found that children with higher blood PFAS levels had significantly reduced antibody responses to routine childhood vaccines. A 2024 follow-up in Environmental Research found that early-life exposure was associated with lower antibodies to MMR and tetanus vaccines at 18 months.
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