Communicating science while navigating misconceptions and mistrust is no easy task. Sometimes a message conveyed about a scientific study is easy to trust and believe, perhaps because of the messenger, or an appeal to common sense and our values.
A recent article by the Environmental Working Group (EWG) titled “Forever Chemicals contaminate nearly 40% of non-organic California-grown produce” delivers a simple and alarming message: forever chemical pesticides are contaminating the fresh fruits and vegetables we eat. This headline may ring alarm bells for many readers, but there is notable scientific weakness in their analyses and thus, their message.
In this article, the EWG relies on pesticide monitoring data from the California Department of Pesticide Regulation (CDPR), published in the 2023 California Pesticide Residue Monitoring Annual Report, which includes information on 3,544 fresh produce samples. Raw data can be found here. The EWG report summarizes that 37% of non-organic California produce samples have residues of per- and polyfluoralkyl substances (PFAS) pesticides and that current use of “PFAS pesticides” raises concerns about soil and water contamination. There are two notable weaknesses in EWG’s analysis of the data: their classification for PFAS, specifically as applied to pesticide classification, and how the safe use of pesticides is evaluated and monitored for human and environmental health.
It’s best to start with the scientific classification of PFAS and what scientists consider “forever chemicals.” PFAS represents thousands of different chemical compounds that have a variety of industrial and medical uses, including waterproofing and flame-retardants. PFAS vary widely in structure and composition, which influences their application as well as human and environmental health impact. Because of PFAS’ wide-scale and varied uses, these chemicals and their by-products can be detected even in remote and pristine environments around the world; and certainly, their presence in agricultural soils and water is a concern and an active area of research.
The EWG article classifies certain pesticides as PFAS based on a broad Organization for Economic Co-operation and Development (OECD) definition for this group of chemical compounds, one of many regulatory and scientific frameworks that classify PFAS based on their toxicity and environmental persistence.
In the U.S., the EPA finalized the definition of PFAS in 2023, after years of research and stakeholder input. The EPA differs from that of the OECD and excludes chemical compounds that contain only one fluorine, having determined that these chemical structures pose a lower risk of environmental persistence. According to the EPA, “Extensive scientific evidence and public input demonstrate molecules with only one fluorinated carbon generally lack the persistence and bioaccumulation properties that are commonly associated with forever chemicals.” The definition of PFAS matters because it conflates all PFAS and “PFAS pesticides” as “forever chemicals” thereby ignoring the importance of PFAS chemical structure to its human or environmental health risk.
Detection of pesticide residues on fresh produce does not equal health risk. Unfortunately, that is also the simple message communicated by EWG in their discussion of CDPR’s study of pesticide residue. Of course, it may seem like common sense that if a chemical that is described as a forever chemical is present as a residue on fresh produce, you wouldn’t want to serve that produce to family. But, common sense, or intuition, is not science (thankfully). If society had relied only on intuition to drive discovery, human health would have missed critical discoveries like penicillin, x-rays and other complex scientific advancements.
If we look at the data in the CDPR residue study with a more complete scientific perspective, the study provides strong support for the absence of any substantial risk to human health from pesticide exposure related to the consumption of fresh fruits and vegetables (grown in California). Here are the facts: 930 non-organic fresh produce samples were tested, and 582 of those samples (or 63%) had no PFAS pesticide (per OECD definition) residue detected, and 348 samples (or 37%) had PFAS pesticide (per OECD definition) pesticide residue detected. Almost 40% may sound like a lot, but what’s important for human health risk assessment is that when pesticide residue was detected, the average residue level represented was a fraction (less than 7%) of the total EPA tolerance level determined as safe for the respective pesticide. In practical terms, any given residue level would need to increase over 10-fold before reaching the regulatory limit established by federal regulatory authorities for fresh produce. Regulatory limits for pesticides in fresh produce are based on several conservative assumptions that include well-established toxicological safety factors (often 100-fold) as well as dietary exposure models. These limits are also designed to overestimate expected real-world residues.
There are multiple rigorous scientific review processes in place before a pesticide is registered, including an additional state registration process completed by the CDPR, which follows an EPA approval of a pesticide. The CDPR review can take additional months to years before a pesticide is allowed to be used in the state. These multiple reviews and conservative residue limits ensure that even the most sensitive consumers can safely eat non-organic fresh produce.
Pesticide residue monitoring studies, such as the one discussed by EWG in its article, frequently detect trace levels of pesticides in produce as part of routine surveillance programs. The USDA Pesticide Data Program is a national pesticide residue monitoring program that provides a comprehensive dataset to inform the U.S. Food and Drug Administration and other government agencies. These residue data are used by regulators and academic human health and environment risk assessors to continuously review and verify regulatory approvals and challenge and further study the impact of pesticides. The data are valuable, and the agricultural industry fully supports their collection and use.
Pesticide use in the production of fresh fruits and vegetables is an important topic for the safety of agricultural workers, consumer health and the environment. Growers are investing in precision application techniques, integrated pest management, biological pesticides and other agronomic practices to continuously improve pest management while maintaining safety, quality and cost. Science will continue to drive improvements in pest management. Well-informed consumers and legislators will ensure the research funding, regulatory frameworks and change management solutions remain available to ensure domestic productivity as the industry transitions to new technologies and approaches.
Simple and misleading messages construing data from complex surveillance studies on pesticide residues meant to alarm are irresponsible and intend to shake confidence in the safety of fresh fruits and vegetables grown in California. The stakes are much too high to jeopardize growers’ access to the best pest management solutions they need to deliver affordable, safe and quality fresh produce for the nation’s families.