Everywhere and invisible: Tracing PFAS from pesticides to our blood

PFAS from pesticides
PFAS (per- and polyfluoroalkyl substances) are found in the blood of 97% of Americans—according to studies from the National Institutes of Health and the Centers for Disease Control and Prevention (CDC). In addition, these chemicals can accumulate in our bodies over time

Found in pesticides used on staple foods—such as corn, wheat, kale, spinach, apples and strawberries—and in everyday residential products like flea treatments for pets and insect-killing sprays, this chemical is widespread, its contamination affecting nearly everyone—through their environment, diet and products. 

What are PFAS?

PFAS are a group of over 12,000 synthetic chemicals introduced in the 1940s. PFAS molecules consist of a chain of linked carbon and fluorine atoms. Their strong carbon-fluorine bonds make them highly resistant to breaking down naturally in the environment. Due to their extraordinarily long breakdown times—sometimes lasting thousands of years—they are often called “forever chemicals”. 

How am I being exposed to PFAS? 

PFAS are known for their water and oil-repellent properties and, due to their durability, are integral to a range of products. This list represents a sample of the many products that can contain PFAS:

Ingestion is the primary route of exposure to PFAS in non-occupational settings, as detailed by the National Academies of Sciences. This typically happens through drinking water contaminated with PFAS or consuming food that has been in contact with contaminated soil or water. PFAS compounds are also prevalent in food contact materials like microwave popcorn bags and fast food packaging—as noted above—, which can leach chemicals into food. Besides ingestion, PFAS can be inhaled from dust in environments with these chemicals—and although less common—dermal exposure is possible. There's also concern about PFAS transferring to fetuses during pregnancy or through breastfeeding, especially near fluorochemical plants where inhalation poses significant risks.

As we see, everyday products and activities contribute significantly to PFAS exposure. This broad impact extends into more specialized areas, such as residential pest control and pet care products. 

PFAS in residential pesticides and pet treatments

Recent research—such as the study published in Environmental Health Perspectives (EHP) —has uncovered the presence of PFAS in agricultural pesticides and residential pest control products, including flea treatments for pets and insect-killing sprays used in homes.

Further compounding these concerns, a report from the Center for Biological Diversity revealed alarmingly high levels of PFAS in popular pet flea-control products: 

  • A topical flea and tick product —a name-brand liquid pesticide applied between the pets’ shoulder blades—contained 2,390 parts per trillion (ppt) of PFAS.
  • A flea collar—a specific plastic band impregnated with insecticides and other ingredients—had 250 ppt of PFAS. 
    Flea collars

    These levels far exceed the EPA's lifetime health advisory for PFAS in drinking water, set at 70 ppt. These findings are particularly concerning for children who frequently interact with treated pets.

    In addition, mosquito control products also contribute to PFAS pollution. According to E&E News, a pesticide widely used for mosquito control in Maryland and other states contains these chemicals—including a notorious compound phased out of U.S. production years ago. This study identified significant levels of PFAS in widely used insecticides. As noted by MPEN Executive Director Ruth Berlin, the combination of these "forever chemicals" with other endocrine-disrupting pesticides is particularly alarming, given the lack of safe disposal methods and—as we’re very well aware—their persistent nature in the environment.

    Given these detailed cases of PFAS contamination, the subsequent section further examines how these elements play into larger regulatory discussions.

    The presence and impact of PFAS in pesticides

    Studies reported in an Environmental Working Group (EWG) article reveal alarming trends regarding the presence of PFAS in pesticide products across the United States. Notably, 14% of all U.S. pesticide active ingredients are PFAS, with nearly one-third of these approved in the last decade.

    Below are the key study takeaways from these studies—which were conducted by the Center for Biological Diversity (CBD), EWG and Public Employees for Environmental Responsibility (PEER)

    Complex chemical mixtures
    • Complex chemical mixtures: Pesticides can accumulate PFAS from multiple sources, resulting in complex chemical mixtures within a single product, complicating risk assessment and mitigation efforts.
    • Human health risks: 40% of PFAS active ingredients classified as immunotoxic by the EPA are likely to weaken the immune system, increasing the risk of infectious diseases.
    • Regulatory oversight: Since 2012, the EPA has often waived immunotoxicity study requirements for pesticides, limiting the detection and management of PFAS-related harms.
    • Water contamination: PFAS-laden pesticides are contaminating waterways, with ingredients detected in streams and rivers across the nation.

      Nathan Donley from the Center for Biological Diversity makes a stark observation in an EWG article: 'This is truly frightening news, because pesticides are some of the most widely dispersed pollutants in the world. Lacing pesticides with forever chemicals is likely burdening the next generation with more chronic diseases and impossible cleanup responsibilities.' 

      Amidst these escalating concerns, another significant issue arises—transparency about the chemical composition of these products, particularly the so-called inert ingredients in pesticides.

      The lack of transparency around inert ingredients

      According to PFAS Free UK, PFAS can be incorporated into pesticides as either:

      • Active ingredients: Intentionally added to kill or control the target pest.
      • Inert ingredients: Encompasses all other substances such as fragrances, dyes, aerosol propellants, solvents, carriers and other materials that support the main action of the pesticide by emulsifying, carrying or propelling it.

        Note: For more detailed insights into active vs. inert ingredients, refer to the EPA's article, Basic Information about Pesticide Ingredients.

        PFAS can be incorporated into pesticides

        Advocates are concerned about the obscured chemical makeup of pesticides that leaves consumers unaware of the actual contents of the products they use at home. Some experts, like Kyla Bennett from PEER, have expressed skepticism over the widespread presence of PFAS in pesticides, questioning in an interview with E&E News about whether manufacturers might be intentionally adding these compounds as inert ingredients. 

        If true, this practice would allow companies to avoid disclosing these chemicals on product labels, as federal law only mandates the listing of active ingredients that target pests. This lack of disclosure is troubling, as inert ingredients can be present in large quantities and be just as toxic as the active ingredients.

        Bennett emphasized the gravity of the situation. In this same interview with E&E News, she stated "We now have five different manufacturers that are selling PFAS-contaminated pesticides," pointing to the findings of PEER’s recent investigations. Despite reassurances from EPA that currently registered pesticides do not contain ingredients with "structures or properties comparable to prominent PFAS," there remains considerable distrust among advocates. They argue that the recent findings highlight the urgent need for greater public transparency around pesticide ingredients, especially as lawsuits seeking to enforce ingredient disclosure have repeatedly failed.

        This issue of non-disclosure extends beyond mere labeling concerns, touching on the broader implications these substances have on public health and the environment.

        The impact of inert ingredients 

        • Overall toxicity: Despite being labeled as 'inert,' these ingredients can significantly influence the overall toxicity of the pesticide. They enhance penetration and persistence, potentially causing unintended effects on humans and wildlife.
          Inert ingredients
        • Systematic review findings: Research published in Environmental Research indicates that many pesticide formulations are more toxic than their active ingredients alone, largely due to inert substances.
        • Biological effects: Inert substances can exacerbate the toxic effects on the nervous system, cardiovascular system and genetic material, often making the overall formulation more harmful than the active ingredient alone, as detailed in an EHP study. These ingredients impact developmental neurotoxicity, genotoxicity and hormone function. 
        • Regulatory gaps: According to the EHP article, testing often only involves the active ingredient, not the full formulation. Federal law only requires disclosure of active ingredients, leaving inert ingredients—which might help pesticides adhere to or penetrate plants—often undisclosed despite their potential toxicity.
        • Disclosure issues: The National Pesticide Information Center notes that manufacturers must list all active ingredients and their percentages but not the names of inert ingredients. This lack of transparency can impede medical treatment for pesticide-related illnesses and reduce corporate accountability.

        Health impacts of PFAS exposure

        Like the often overlooked dangers of inert ingredients in pesticides, the pervasive environmental presence of PFAS compounds also leads to numerous adverse health effects:

          Reducing your exposure to PFAS

          Toxic-Free Future offers valuable guidance on protecting yourself and your family from the dangers of PFAS. Here are some practical steps you can take:

          • Choose safer products: Opt for clothing, furniture, bedding and household items that are washable and free from stain- or water-resistant treatments. For items that need to be waterproof or water-resistant, seek out those explicitly labeled as PFAS-free. Note: Ensure they are free of the entire class of PFAS compounds and avoid items labeled as “PFOA-free” which may still contain other PFAS.
            Microwavable popcorns
          • Avoid greasy packaged foods: Foods such as microwave popcorn or fast food often come in packaging with grease-repellent coatings that contain PFAS. Choosing fresh or home-cooked meals can minimize your exposure.
          • Select PFAS-free personal care: Be cautious of personal care products containing ingredients with “fluoro” or “perfluoro.” Also, avoid non-stick cookware and opt for safer alternatives like stainless steel or cast iron.
          • Engage with brands and policymakers: Let retailers, brands and policymakers know that you support policies and market changes to replace PFAS with safer alternatives. Advocating for change can drive the adoption of non-toxic products across the market.

            Commitment to safety at Dr. Killigan's

            At Dr. Killigan's, we believe in full transparency and safety. Our products:

            • List all active and inactive ingredients clearly on the label.
            • Avoid the use of fluorination in our plastics, ensuring no PFAS are present.
            • Commit to PFAS-free products, safeguarding your health without compromising effectiveness.

              By choosing products like ours and following the above steps, you can significantly reduce your PFAS exposure and contribute to a healthier environment.

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