25
Sep
PFAS, Pesticide, Pharmaceuticals, and Heavy Metals Found in Backyard Eggs Underscore Toxic Threat
(Beyond Pesticides, September 25, 2025) Reinforcing numerous studies’ findings of widespread environmental contamination with PFAS (per- and polyfluoroalkyl substances), heavy metals, pesticide metabolites, and pharmaceuticals, researchers detected the chemicals in noncommercial backyard eggs laid in Greece, according to a study published in Science of The Total Environment.
The researchers found that “[o]nly 9 out of 17 samples were compliant to the limit….set by the [European Union] for the sum of PFHxS [perfluorohexanesulfonic acid], PFOS [perfluorooctanesulfonic acid], PFOA [perfluorooctanoic acid], and PFNA [perfluorononanoic acid].†They continue: “[A]s regards PFOS, PFHxS, and PFNA, seven, six and one out of 17 samples, respectively, were above the ML (maximum limit) as set by the EU.â€
With current regulatory standards focused on evaluating exposure to individual chemicals and, in some instances, cumulative risk associated with chemicals that have a common mechanism of effect, this study points out the importance of looking at mixtures of chemicals and the potential synergistic effects. There are some fluorinated pesticides defined as PFAS due to their molecular structure and high toxicity, which makes the chemicals highly persistent in the environment. Center for Food Safety, Center for Biological Diversity, Public Employees for Environmental Responsibility, reviewed the full list of active ingredients registered with U.S. Environmental Protection Agency and found that 66 of the 471 (or 14 percent) qualify as PFAS (see Daily News here); in 2025 alone, EPA approved at least four new active ingredients–Cyclobutrifluram (Herbicide for nematodes), Diflufenican (Herbicide for corn and soybeans), Isocycloseram (Insecticide seed treatment), and Trifludimoxazin (Herbcide for oranges, apples, peanuts, etc.)–that also share the chemistry of forever chemicals, according to reporting by Civil Eats.Â
Background and Methodology
“The main objectives of this study were to examine the occurrence of PFAS in home-produced eggs collected from various areas of Greece, to identify potentially contaminated regions and to estimate the probable risk of PFAS intake through egg consumption,†according to the researchers. The sampling of eggs for this study was conducted between April and October 2023, with 75 eggs collected from seventeen backyard coops across five Greek prefectures (local political subdivisions). There were 4-5 eggs gathered from each group, resulting in 17 pooled samples from the chicken coops. The target chemicals for this study included 46 PFAS, as well as any other detectable levels of heavy metals, pesticides, and pharmaceutical residues. The health risk assessment was based on estimated weekly intakes (EWIs) for PFAS and heavy metals from egg consumption. The methodology focuses on screening rather than deriving dietary exposure values for pesticides and pharmaceuticals.
The authors acknowledge this as one of the limitations of this study, however it is important to emphasize that this separation of scientific analysis on exposure levels based on individual classes of chemicals (e.g. pesticides, fertilizers, heavy metals, pharmaceuticals, other petrochemical substances, and their breakdown materials or metabolites) speaks to a broader challenge of regulatory systems failing to engage in comprehensive scientific research that addresses ongoing concerns about public health and ecosystem threats. Considering that researchers used a methodological screening method that emphasizes breadth (detection of pesticide compounds) over actual exposure (quantity of exposure), a recommendation for future studies would be to consider concentration data through tools like liquid chromatography-tandem mass spectrometry (LC-MS/MS) with multiple reaction monitoring (MRM) that “can measure many chemical species quantitatively in the same analysis.†(See here for a widely cited primer on modern mass spectrometry techniques in the clinical diagnostics context.) With a stronger screening tool, quantified residues on pesticides and pharmaceuticals could be integrated with the existing EWI data on heavy metals and PFAS to estimate chronic dietary chemical exposure.
It is noteworthy that the authors did not assess quantitative exposure estimates for all of the contaminants in this study (just PFAS and heavy metals) for a number of reasons explored below, one of the most important being that regulatory frameworks for multiple classes of chemical exposure in the U.S. and European Union (and most other nations) are fragmented and fail to assess targeted quantification of pesticide exposure and drift more specifically. Simultaneously, cumulative impacts with other potentially hazardous substances listed under other U.S. environmental statutes are not evaluated in combination with pesticides (e.g., Comprehensive Environmental Response, Compensation, and Liability Act [CERCLA], Resource Conservation and Recovery Act [RCRA], Clean Air Act [CAA], Clean Water Act [CWA], Federal Insecticide, Fungicide, and Rodenticide Act, Endangered Species Act, Emergency Planning and Community Right-to-Know Act [EPCRA], among others).
The researchers are based at Greek universities, including National and Kapodistrian University of Athens and University of the Aegean. They declared that they “have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.†The work in this study was supported by the European Commission through various grant programs, including HORIZON-RIA (Horizon Europe Research and Innovation Actions), AgriDataValue, and Horizon 2020 research project Zero Pollution of Persistent, Mobile Substances (ZeroPM).
Results
The researchers were able to confirm their hypothesis that backyard chicken eggs found across multiple regions led to exposure to a cocktail of contaminants, opening the potential for significant long-term health burdens based on existing regulatory thresholds.
The European Food Safety Authority (EFSA), the EU counterpart to the U.S. Food and Drug Administration (FDA), has established a regulatory threshold for the estimated weekly intake of numerous PFAS (PFOS, PFOA, PFNA, and PFHxS), with various regions facing contamination. Attica and Ilia had the highest concentrations, where the average PFAS concentrations for the four tested examples were high enough to exceed EFSA’s tolerable weekly intake (4.4 ng/kg bw/week) and therefore faced the most significant degree of contamination.
The researchers detected six pesticide residues in the gathered samples, including the herbicide dinoterb, insecticides DEET and fipronil sulfone (transformation product), industrial wood preservative pentachlorophenol, pesticide synergist piperonyl butoxide, and fungicide tricyclazole. They also detected the residue of various pharmaceutical products (antibiotics like enrofloxacin, anti-parasitic drugs like ivermectin, and other random residues like carbamazepine, an anticonvulsant, that were detected more sporadically. Pesticides and pharmaceutical residues, however, were found below quantification limits based on the restraints identified in the methodology analysis.
Several toxic heavy metals (e.g., cadmium and lead) and other elements that are toxic at high levels (e.g., iron, zinc, and selenium) were also detected, with the estimated weekly intakes above EFSA’s health-based threshold for cadmium and lead in certain regions (Magensia and Ilia).
“The exposure pathways responsible for the PFAS found in Greek egg samples were not studied in the current article,†say the authors. “However, according to the literature, the potential PFAS exposure pathways for hens living in chicken coops seem to be soil, water, and food.†See a recent related Daily News, Review of Science on Glyphosate Weed Killer in Poultry Production Highlights Extraordinary Health Threats, for additional context on the threat of chemical exposure via poultry products.
Previous Research and Actions
For backyard gardeners and farmers, one of the most direct exposure pathways to the full range of chemical soup that is described in this study is through the sourcing of compost.
One of the more elevated fights in recent memory between the National Organic Standards Board and industry interests looking to weaken regulations is on the issue of allowed materials in compost used on certified organic operations. A petition submitted by industry-aligned Biodegradable Products Institute (BPI) sought to allow “compost feedstocks†that might include, for example, “compostable†plastic food containers. It is the position of Beyond Pesticides that compost in organic production should contain only plant and animal waste, and not synthetic materials that could introduce hazardous contaminants like PFAS and microplastics, the latter of which have been found to have synergistic impacts with chlorpyrifos (see Daily News here) and proven evidence of adsorption of additional active ingredients. (See Daily News here.) The current regulations require compost to be made from manure and plant wastes, allowing only synthetics on the National List of Allowed and Prohibited Substances —that is, those that have specifically been approved by the NOSB and USDA through a public comment process. The only synthetic inputs into compost that are currently allowed are newspaper and other paper. (See Daily News here.) See here for a copy of Beyond Pesticides Spring 2025 comments to the NOSB Crops Subcommittee on the proposal on synthetic feedstocks.
This issue has emerged as lawsuits continue to be brought forward to federal courts on PFAS contamination impacting farmers (organic and non-organic) and consumers across the United States, including farmers in Texas and Maine, and consumers nationwide. In July 2024, Public Employees for Environmental Responsibility (PEER) filed a lawsuit against the U.S. Environmental Protection Agency (EPA) on behalf of a group of ranchers and farmers in Texas harmed by PFAS-contaminated biosolids. The plaintiffs charge that their health and livelihoods were severely damaged due to contaminated biosolids leaching from neighboring properties onto their land. (See Daily News here.) In the spirit of environmental and agricultural justice, the discovery of widespread contamination of farmland in Maine and years of grassroots advocacy led to the development of the first-in-the-nation PFAS Fund, a $70 million federal-state partnership aimed at providing compensation for commercial farmers whose health, business, and land have been impacted by PFAS contamination—offering a potential roadmap for other states and Congress to adopt remediation efforts more broadly. (See Daily News here.) Beyond Pesticides has also engaged in litigation efforts on potentially contaminated products, as we filed a lawsuit against The Scotts Miracle-Gro Company and GreenTechnologies, LLC last fall for allegedly misleading consumers on the hazardous nature of their fertilizer products, which contain sewage sludge (often referred to as biosolids). (See Daily News here.)
For more information and context on the potential for compost as both a threat and an ally to organic food systems, see its dedicated Daily News section here.
Call to Action
Federal law on pesticides and organic farming only goes so far as the public is willing to engage in the process and prove that it is of broader public interest. The value of U.S. federal organic law, as defined by Organic Foods Production Act (OFPA), is that there is a requirement to host biannual NOSB public meetings to hear from the public on a suite of various issues.
Beyond Pesticides has developed and actively maintains the Keeping Organic Strong resource hub, a one-stop shop for you to learn about changes in organic regulations, see the Fall 2025 issues, and review our written comments for all issues that will be raised before the NOSB and five associated subcommittees. The Fall National Organic Standards Board meeting will be held both in person in Omaha, Nebraska, and virtually, via live-stream from November 4, 2025, to November 6, 2025. The deadline for written comments on the Fall 2025 issues is 11:59 pm EDT on October 8, 2025, and the Public Comment Webinars will be held on October 28 and 30, 2025, from 12 pm to 5 pm EDT.
You can also take action here by contacting your members of Congress to co-sponsor and support organic bills that have recently been introduced in the first year of the 119th Session of Congress.
There is currently an opportunity for the public to weigh in on the integrity of national organic standards, as the National Organic Standards Board convenes to discuss key issues and allowed materials in organic agriculture. The public can see a discussion of issues before the board and submit comments (using Beyond Pesticides’ positions) by October 8. To submit comments, please click HERE. For more background, see Keeping Organic Strong and the Fall 2025 issues page.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Science of The Total Environment
