19
Sep
EU Risk Assessment Fails to Predict Limits of Personal Protective Equipment (PPE)
(Beyond Pesticides, September 19, 2024) An article published in the journal Science of the Total Environment finds that the European Union’s (EU) risk assessment process, required for registration, fails to accurately or reliably predict pesticide exposure rates, sometimes by several orders of magnitude. Pesticide registration in the EU leverages the Agricultural Operator Exposure Model (AOEM)—a predictive model developed in 2014 to estimate expected non-dietary pesticide exposure levels for operators [pest control operators in the U.S.] based on a very limited set of data generated by the pesticide industry. Models that predict real-world exposure and underestimate field data raise critical questions about the efficacy of risk assessment reviews that determine product labels and allowed level of harm.
By comparing the dermal exposure measured during a field study conducted in a nonagricultural area with the corresponding values estimated by AOEM, researchers in France add to the body of scientific literature indicating that the fossil fuel and petrochemical pesticide industry data cannot be relied upon as a benchmark to ensure public health and safety.
The study describes the difficulty and complexity of calculating the ability of protective equipment to provide protection. According to the authors, “[AOEM] underestimated hand exposure by 42 times and it systematically underestimated the exposure when the operators were wearing gloves, especially during the application. The model failed at being conservative regarding hand exposure and highly overestimated the protection afforded by the gloves.†The authors conclude that AOEM yielded higher estimations than field measures and state, “(h)owever, hand exposure was systematically underestimated when hands were protected by gloves, meaning that the model overestimates the protection that they afford. While AOEM is a fast and cheap predictive tool compared to laboratory exposure assessment, it is based on a limited number of studies that were carried out exclusively under controlled conditions by the pesticide companies. No studies have been conducted in the nonagricultural area, even though there are some similarities with the agricultural sector regarding the way pesticides are used.†Since the knapsack sprayer is common equipment used in agriculture and nonagricultural areas, the sample size used by AOEM is called into question—having only four studies with this type of equipment included in the model. “It therefore appears crucial to consider academic studies conducted in real work conditions and to modify the model so that it estimates operator exposure accurately,†the authors conclude.
To test AOEM, researchers examine data from a 2011 exposure study of private and public gardeners in France wielding knapsack sprayers (also known as backpack sprayers) to apply glyphosate products in nonagricultural settings. All participants are male, with a mean age of 40 and prior experience spraying glyphosate weed killers. The whole-body method was used to determine dermal exposure, as described by the Organisation for Economic Co-operation and Development (OECD) Guidance Document for the Conduct of Studies of Occupational Exposure to Pesticides During Agricultural Application. To determine actual exposure, operators wore pre-washed cotton undergarments (long pants and a long-sleeve t-shirt) and cotton gloves. The clothes were tested daily while the gloves were changed between application phases.
Theoretically, AOEM would be expected, according to the design, to conservatively estimate pesticide exposure rates. As such, the model should overestimate the amount of predicted pesticide exposure. In terms of specific numbers, AOEM estimated the median overall daily exposure to be 27.9 mg/day, which was higher than what was actually measured in the field. For body exposure, AOEM’s estimate was 20 mg/day, again higher than the field measurements. However, the most significant difference was seen in hand exposure: AOEM estimated it at only 0.11 mg/day, which was 42 times less than the field-measured exposure of 4.62 mg/day. According to AOEM, hands accounted for 26% of the total daily exposure, whereas in the field study, hands accounted for 84% of actual total daily exposure.
Ultimately, the model results do not correlate with the field results, suggesting that the model’s overall precision is lacking. Considering that the model is used to determine whether a pesticide is safe for public use, such gross miscalculations could result in massive unintended and unexpected exposures to highly toxic chemicals, the authors note. The study concludes that the model is not sufficiently cautious regarding hand exposure and recommends that field studies conducted under real-world conditions by academic researchers are needed to improve AOEM systemically, particularly for nonagricultural settings, to provide more accurate exposure estimates and strengthen safety measures.
Additional critiques offered by the authors include the fact that the model does not apply empirical or real-world field data to inform estimates. AOEM relies on 34 studies, some unpublished, despite the availability of academic research available on nonagricultural sectors. In addition, certain studies included are not published, limiting the availability of detailed methodologies for peer and public review. AOEM incorporates a total of 88 data points, but with only four studies involving knapsack sprayers, this study argues that the calculations may be too simplistic to account for the complexity of real-world exposure in different environments. Furthermore, despite the availability of applicable research, all the studies employed in AOEM were conducted by pesticide companies and not published in peer-reviewed journals where they can be critiqued. Perhaps most importantly, only four of the studies involved the use of a knapsack sprayer, which means the model cannot possibly account for average variations in applications under this method.
By not considering empirical use and field testing, the EU approach used for estimating pesticide operator exposure is akin to the pesticide regulation process conducted by the U.S. Environmental Protection Agency (EPA), which relies on pesticide manufacture’s supplied data on only the active ingredient, rather than the pesticide product formulation. Beyond Pesticides has long criticized EPA’s pesticide risk assessment process which ignores the availability of less toxic, viable alternatives, as proven in organic agriculture and organic land care. Instead of delaying important applicator standards, public health and environmental advocates call on EPA to honor the agency’s mandate to protect against “unreasonable†adverse effects by evaluating the reasonableness of risk with an assessment of alternative organic practices that eliminate their use (see here and here).
Beyond Pesticides’ coverage of farmworker exposure to pesticides and resultant harms began in the late 1970s and continues to this day, with recent attention drawn to a long history of health threats, U.S. and international pesticide regulatory failures, and (U.S.) structural racism, operationalized through disproportionate risk, that is imbued in the chemical-intensive agricultural system that feeds the nation and world. (See here, here, here, and here). Jay Feldman, executive director of Beyond Pesticides, adds, “These practices are particularly abhorrent, given the availability of organic compatible products that do not cause harm.â€
With the knowledge that risk calculations are often not adequately protective and that the chemical widely used can be replaced by practices and products without the hazards, Beyond Pesticides advocates for the adoption of organic land management, a systems approach that eliminates toxic chemical pesticides and fertilizers while building organic matter and soil biology (see here) as a means of cycling nutrients for plant health. This approach is successfully and economically used in managing lawns, parks, and playing fields across the country, including as the foundation of the Parks for a Sustainable Future Program. Without proper enforcement and oversight, applicators, their clients, and the environment continue to be at risk. The study’s recommendation to call for stricter applicator standards is incremental and not a holistic solution that can meet the triple threat of existential crises stemming from chemical-intensive agriculture and land use. Continued use of petrochemical pesticides and fertilizers not only threaten the health and safety of pesticide applicators, including farmworkers, but their families and neighbors, the broader public, and the environment by means of the degradation wrought upon vital natural resources that sustain all life on Earth.
Beyond Pesticides has long sought a broad-scale marketplace transition to organic practices that, as a default, prohibits the use of synthetic pesticides by law—unless subject to rigorous health and environmental standards and recommended by the National Organic Standards Board (NOSB)—and requires a systems-based approach that is protective of health and the environment. This approach never allows the use of highly toxic synthetic pesticides, such as toxic organophosphates, and advances a viable, scalable path forward for growing food. Find out more about why organic is the right path forward for the future of farming by going to Beyond Pesticides’ organic agriculture webpage.
Take action today to keep organic strong! The NOSB is receiving written comments from the public, which must be submitted by 11:59 EDT on September 30, 2024. Written comments can be submitted via our “click and submit†form or directly through Regulations.gov. Click here to read suggested comments on our priority issues!
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
Pesticide exposure in greenspaces: Comparing field measurement of dermal contamination with values predicted by registration models, Science of The Total Environment, April 2024
https://doi.org/10.1016/j.scitotenv.2024.170816
EPA’s Worker Protection Standard Fails to Protect Farmworkers’ Health, Report Finds, Beyond Pesticides Daily News, February 14, 2024
Toxicology Human Health Threats, Pesticides and You, 2023-2024
Science: Human Health Threats, Biodiversity, Climate, Pesticides and You, 2022-2023
Pruitt’s EPA Delays New Rules to Protect Pesticide Applicators, Beyond Pesticides Daily News, May 17, 2017
Precarious Protection: Analyzing Compliance with Pesticide Regulations for Farmworker Safety, Center for Agriculture and Food Systems at Vermont Law and Graduate School, the Harvard Law School Food Law and Policy Clinic, and Farmworker Justice, December 2023
Essential and in Crisis: A Review of the Public Health Threats Facing Farmworkers in the US, Johns Hopkins Center for a Livable Future, May 2021
The Organic Farming Response to Climate Change, Pesticides and You, 2007
