31
Jul
Science on “Forever Chemicals” (PFAS) as Pesticide Ingredients and Contaminants Documented
(Beyond Pesticides, July 31, 2024) The latest commentary on “forever chemicals” in Environmental Health Perspectives captures growing concerns for the class of per- and polyfluoroalkyl substances (PFAS) that are found in pesticide products and cause persistent contamination that threaten human health and the environment. The authors share, “Given that pesticides are some of the most widely distributed pollutants across the world, the legacy impacts of PFAS addition into pesticide products could be widespread and have wide-ranging implications on agriculture and food and water contamination.”
Fluorination, which adds fluorine to a compound, is used to modify properties, such as the stability of chemicals. It can also increase residual activity of pesticide ingredients. Fluorinated molecules, including PFAS, are “a serious environmental health concern owing to their highly persistent nature, often potent toxicities, potential to bioaccumulate, and widespread presence in people, animals, and the broader environment,” the authors state. They continue in saying, “The long-term impacts of using mixtures of extremely persistent chemicals on potentially hundreds of millions of acres of US land every year is, to us, a cause for concern.”
The commentary, titled “Forever Pesticides: A Growing Source of PFAS Contamination in the Environment,” explores how and to what extent PFAS can be introduced into pesticide products, and how this impacts health and the environment, through public records requests to state and federal agencies in the United States and Canada, as well as from publicly accessible databases. As a result, the authors find that, “The biggest contributor to PFAS in pesticide products was active ingredients and their degradates [chemical breakdown products]. Nearly a quarter of all US conventional pesticide active ingredients were organofluorines and 14% were PFAS, and for active ingredients approved in the last 10 y[ears], this had increased to 61% organofluorines and 30% PFAS.”
The classification of PFAS is also of concern, as the number of PFAS in the U.S. heavily depends on the U.S. Environmental Protection Agency (EPA) definition, which is on a “case-by-case” basis during rulemakings and agency actions. The broad definition of PFAS as a compound with at least “one fully fluorinated carbon” has been adopted by many states and other authorities, such as the U.S. Geological Survey (USGS) and the Toxics Release Inventory (TRI) under Section 313 of the Superfund Law, or Emergency Planning and Community Right-to-Know Act (EPCRA).
Aside from active ingredients that are defined as PFAS, there are also inert ingredients that play a role in contamination. While inert ingredients do not need to be disclosed on labels and have limited toxicity testing as a part of pesticide formulations, they are often “far from being inert,” the authors say. “Many of these ingredients have chemical properties that can influence the toxicity or alter the bioavailability of the active ingredient or have unintended off-target effects themselves to people and wildlife.”
The authors submitted a public records request to EPA and received a response that “indicated that the agency had 24 registered inert ingredients that it had identified as PFAS or that the agency suspected may be PFAS.” In reviewing this list, the authors confirmed 11 of the compounds contained “fluoro” in the ingredient name field and should be classified as PFAS. Canada’s Pest Management Regulatory Agency (PMRA) also has a list of currently registered inerts, seven of which were identified as being PFAS. Since inert ingredients can be even more toxic than the active ingredients and are undisclosed within pesticide products, this raises additional considerations.
In compiling and analyzing test data by USGS for pesticides in ~500 streams throughout the U.S. between 2013 and 2017, 225 pesticide compounds were found in water samples. Twenty-nine total PFAS analytes were identified, 13 of which are PFAS active ingredients and 16 are fluorinated degradates. Degradates, such as trifluoroacetic acid (TFA), which correlate strongly with pesticide use, can be detected in waterways and food. “The USGS estimates that anywhere from 10.4 to 15.9 million kg of PFAS active ingredients are used across the United States each year—the vast majority of which contain at least one—CF3 [trifluoromethyl] group and could potentially metabolize into TFA or other persistent, fluorinated water contaminants,” the authors state. They continue with, “Organically grown food has also been found to have lower levels of TFA than food grown with synthetic pesticides,” which offers a healthier alternative.
While the practice of fluorinating plastic containers started in the 1950’s, PFAS leaching from storage containers, especially in those that contain pesticides, has gained publicity more recently as a major topic of concern. “Today hundreds of millions of high density polyethylene (HDPE) containers that contain agricultural products, personal care products, household cleaning supplies, home improvement products, and food are fluorinated each year,” the authors state, continuing, “It is estimated that 20%–30% of all hard plastic containers used in the agricultural sector are fluorinated, elevating concerns about widespread PFAS contamination.”
In 2021, EPA committed to not only facilitate the remediation of legacy PFAS contamination but also to intervene to limit the introduction of unnecessary new PFAS into the environment through its PFAS Strategic Roadmap. The overwhelming body of science that highlights PFAS throughout the environment, and the negative effects they have on human health and the environment, show that EPA is failing at this task. “The enormous potential for human exposure and environmental contamination belies the importance of understanding complete product compositions and their environmental fate and transport,” the authors comment, which is lacking in current EPA risk assessments. PFAS are highly persistent and analyzing chemicals within this class over only a few months does not capture the entire picture of how these chemicals transform over long spans of time.
PFAS, including chemicals in the group such as PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonic acid), “are known to harm the immune system, weaken the antibody response to vaccinations, and increase the risk of infectious disease,” the authors comment. The immunotoxic effects of PFAS threaten human health, and yet are not fully evaluated by EPA. As the authors share, “Between 2012 and 2018, the US EPA granted 223 of 229 waiver requests (97%) for immunotoxicity testing of pesticide active ingredients… Troublingly, the number of active ingredients that are fluorinated or that meet the definition of PFAS has increased considerably from 2012 to the present—the very time period that the US EPA granted 97% of waiver requests for immunotoxicity study requirements. This suggests that fluorinated or PFAS active ingredients may be more likely to be immunotoxic than other types of active ingredients and that any associated immunotoxicity may not be accounted for owing to the lack of requirement for scientific study.”
As a result of these findings and previous documentation of the consequences of PFAS being released into the environment, the authors recommend that:
1) the practice of fluorinating plastic containers should be discontinued,
2) all pesticide ingredients including inerts need to be disclosed on pesticide labels and material safety data sheets,
3) immunotoxicity studies should no longer be waived,
4) all PFAS pesticides and their degradates must be fully evaluated for environmental persistence, and
5) the US federal government must expand environmental monitoring and biomonitoring programs to include all PFAS pesticides.
One of the authors, Kyla Bennett, PhD, is a former EPA official and now works with the Public Employees for Environmental Responsibility (PEER) nonprofit. In an article in The Guardian, Dr. Bennett says, “We should be eliminating PFAS from all products, but particularly pesticides because you’re spraying them on crops, and there’s not a more direct way to expose the population than that… We should not be going in this direction.” A new lawsuit filed by PEER targets the inaction of EPA on PFOA in plastic containers. Due to the widespread risks to health, the complaint says that EPA must “halt the manufacture and distribution of tens of millions of plastic containers with dangerous levels of PFOA” under the Toxic Substances Control Act (TSCA).
A recent petition, submitted by the Center for Food Safety (CFS) on behalf of 12 other petitioners, including Beyond Pesticides, echoes these concerns and asks EPA to: “(1) ban PFAS as pesticide ingredients; (2) adopt a broad definition of PFAS chemicals that reflect the current scientific understanding of the class of chemicals; (3) prohibit the use of PFAS-containing containers for pesticide storage; (4) mandate reporting of PFAS contamination from pesticide registrants; and (5) prevent future contamination by requiring pesticide manufacturers to submit data specific to PFAS before future registrations can be approved.” In the latest Action of the Week, readers can urge EPA to approve this petition, and tell Congress to demand that EPA act immediately.
The path forward is organic land management. The National Organic Standards Board (NOSB) reports directly to the U.S. Secretary of Agriculture and provides a sustainable system with public input and standards as defined by federal law for farming practices. These practices prioritize soil health and biodiversity and can provide an alternative to plastics, PFAS, and pesticides with organic production and packaging. The ongoing development of organic standards through NOSB offers national requirements for the production, handling, processing, and labeling of organically grown food that supports human health and the environment. Beyond Pesticides is working to get plastics out of organic. (See here and Beyond Pesticides’ comments to the NOSB.) You can grow your own organic food or buy organic products to help reinforce the shift away from petrochemical pesticides and fertilizers to healthier alternatives.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Donley, N. et al. (2024) Forever Pesticides: A Growing Source of PFAS Contamination in the Environment, Environmental Health Perspectives. Available at: https://ehp.niehs.nih.gov/doi/10.1289/EHP11900/.
