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By Thomas Green, PhD, chair, HHRA Board of Directors

Consumer Reports (CR) published a cover story today on pesticides on fruits and vegetables in the US food supply. CR concluded that “20% of the 59 fruit and vegetables tested posed a high risk from pesticides.” Blueberries, green beans, watermelons, bell peppers, potatoes, kale, and mustard greens were among the 12 highest-risk foods.

What’s going on here?
The United States Department of Agriculture (USDA) annually publishes a report with results from pesticide residue sampling completed two years prior. In January, the USDA’s report assured consumers that 99% of more than 10,000 samples of foods collected in 2022 had pesticides at or below EPA-set legal limits.

To add to the confusion, the EWG (formerly Environmental Working Group) follows up each USDA report with its “Shopper’s Guide to Pesticides in Produce” and its widely promoted Dirty Dozen and Clean 15 lists. This year, EWG “determined that 75 percent of all conventional fresh produce sampled had residues of potentially harmful pesticides.” Blueberries, green beans, bell peppers, potatoes, kale, and mustard greens made the EWG’s Dirty Dozen, but not watermelon. Grapes and peaches also made the Dirty Dozen but didn’t make CR’s list of 12 highest risk foods.

Three very different perspectives, yet all three organizations use the same data source! Residue data are generated by the USDA, which collects and tests domestic and imported food samples from our food distribution system in multiple states each year. Why the discrepancy in findings?

Here’s the story
The USDA uses “residue tolerances” established by the US Environmental Protection Agency (EPA). Residues under the tolerance level are regarded as safe. Foods with pesticide residues over the tolerance render the food adulterated. Food declared as such is supposed to be removed from the marketplace but fresh produce rarely is.

The EPA tracks total dietary exposures to a given pesticide based on all tolerances that have been approved and by law must determine that there is a “reasonable certainty of no harm” from total exposures.

As reported by the USDA this year, of the 10,665 samples collected in 2022, 325 had pesticide residues exceeding the tolerance or present in the absence of a tolerance, or about 3% in total. A third of the samples with over-tolerance, presumptively unsafe residues were US-grown; two-thirds were imported foods. In 2022, 27% of samples tested had no detectable residues.

The EWG uses pesticide residue detections, so regardless of the tolerance level set for a pesticide, each residue detected is counted. A food makes the Dirty Dozen list if it is among the foods with the highest number of pesticide residues. Residues of some pesticides known to pose health hazard are weighted more heavily. The EWG typically lumps US and foreign-grown food in their report.

In the report released today, CR analyzed USDA data on 59 foods in more than 26,000 samples tested by the USDA over seven years (2016-2022). CR used EPA-set toxicity thresholds for most pesticides but added the full 10-fold safety factor called for in federal law to several more high-risk pesticides than the EPA does. CR scientists consider the EPA’s tolerances to be too high for some pesticides, so they developed these lower limits for “pesticides that can harm the body’s neurological system” or are suspected of interfering with human hormones.

The analytical work supporting the CR report was completed by a team led by the HHRA’s founder and first executive director Chuck Benbrook, and grounded in analyses conducted using the Dietary Risk Index (DRI) system currently housed on the HHRA’s website. The DRI is also included in the Pesticide Risk Tool, developed by a team I led and housed at the IPM Institute. I co-founded the IPM Institute in 1998 where our Sustainable Food Group continues to work with food companies and supply chains to reduce pesticide risks among other initiatives.

So which report wins the day?
All three have value, and all three point to opportunities for improvement.

Without the USDA’s highly regarded pesticide residue testing program, efforts to reduce the frequency of high-risk residues would be like shooting in the dark. Of the three analyses, the USDA’s report represents the least conservative approach to estimating risk. Yet the level of tolerance violations reported by the USDA represents hundreds of millions of presumptively unsafe servings of food in the US every year!

The EWG and CR take a more conservative approach to estimating and avoiding risk. Both organizations recognize that not all potential risks have been identified or accounted for in EPA risk estimates. For example, we all ingest multiple pesticide residues daily via food and drink, but their combined risk is not taken into account by the EPA.

CR’s approach is more science-based and more closely aligned with the EPA’s dietary risk assessment. CR’s methodology is driven by measured residue levels, EPA-set exposure thresholds based mostly on animal studies, and standard food serving sizes. Not all pesticide residues pose equal risk, in fact they vary by over 10,000-fold!

What’s the bottom line?
All three organizations recommend that everyone should eat lots of fresh fruits and vegetables. The benefits to health outweigh the risks of pesticide exposure.
The EWG recommends consumers buy organic versions of its Dirty Dozen. CR recommends limiting consumption of foods they have identified as highest risk to ½ serving per day or less, and buying organic when available and affordable.

A common question is, “Can I remove pesticide residues by washing?” Before testing, food samples used in these reports are at a minimum lightly washed. Additional washing may help but will not achieve anywhere near our potential to reduce risk.

It’s important to highlight that US-grown conventional food samples have generated fewer tolerance violations year after year compared to imported food, and that organic foods have also consistently generated far fewer violations than conventionally grown samples.

In addition, the overall pesticide risk reduction achieved for birds, bees, and people since passage of the Food Quality Protection Act in 1996 has been astounding and readily documented by using the Pesticide Risk Tool. This achievement is a credit to our US regulatory system, producer willingness to innovate by integrating multiple practices, and pesticide manufacturers who have continually brought lower risk options to the market for both conventional and organic production.

What more needs to be done?
The historic risk reduction achieved in US-produced food also points to the potential for producers and regulators in other countries, and for producers of US conventionally grown foods to further reduce risk. The challenge is dealing with the small percent of samples that pose risks above what the EPA regards as “safe,” including some far above EPA’s safety threshold. Many tolerances need updating – many are not set at levels the EPA now considers safe. All tolerances need to be set such that residues in a given food-pesticide combination do not exceed the EPA’s level of concern.

Pesticide application accuracy is critical. Some of the most extreme tolerance violations are likely due to inadequate applicator training, improper mixing of chemicals, and/or lack of careful calibration of application equipment so that the rates applied do not exceed limits set on product labels. With optimum support and incentives, all application equipment could have the latest technology to maximize accuracy, including ongoing monitoring of performance and automatic alerts of deviation from desired application rates.

Our regulators, producers and the food industry need far greater support for ongoing efforts to limit the frequency of high-risk residues in food. The EPA’s current budget in real dollars is far less than it was decades ago, despite tremendous growth in our population, economy, and the intensity of pesticide use. The same goes for USDA’s core funding for pest management, stuck at a paltry $20 million a year for nearly two decades.

USDA’s Natural Resources Conservation Service (NRCS), charged with supporting conservation on private lands, invests only about 1% of its resources for producer technical and financial assistance supporting more effective, less chemical-dependent pest management opportunities. This low investment is despite the NRCS studies showing only about 10% of cropland acres surveyed have a high level of Integrated Pest Management (IPM) practices in place. IPM practices are designed to reduce risks to health and environment, while also delivering economic returns in agriculture, natural areas and community settings.

While US certified-organic retail sales have grown by an average of 8% a year over the last decade, certified-organic crop and livestock acres have grown from 1.8 million in 2000 to only 4.9 million in 2021, not even 1% of total US agricultural acres.

Pest management system investments are a crucial component of the infrastructure supporting a safe and nutritious US food system. It is critical to reduce the influx of new imported pests, while also developing lower risk solutions to existing pest problems. It’s absolutely certain that many high-risk pesticide uses are due to pest problems with inadequate and/or unaffordable low risk options. It is also likely that some tolerance violations occur because some producers skirt the law to save crops and livelihoods when pushed to the wall by lack of alternatives.

The ability to precisely identify the truly high-risk pesticide-food combinations, and track where they are coming from and how they were grown, is a game-changer. This creates an opportunity for targeted efforts focused where high risks are being generated, including the opportunities catalogued above.

Critical public policy improvements are undoubtedly being held back by politics, and the roots of political gridlock can be found in how political campaigns are financed in the US. Our failure to pursue further opportunities to reduce pesticide and other risks, including more effective regulation, enforcement, education, training and incentives is unduly influenced by large dollar donors’ ability to get candidates elected who will represent their interests over the interests of consumers and producers alike.

Until we implement a more intelligent system for choosing our policymakers, we’re unlikely to make the progress we now have the tools to achieve.

For more information on DRI methodology and applications:
Benbrook, C., & Davis, D. “The dietary risk index system: a tool to track pesticide dietary risks,” Environmental Health, 2020, 19(1); DOI: 10.1186/s12940-020-00657-z
Benbrook, C. “Tracking pesticide residues and risk levels in individual samples—insights and applications,” Environ Sci Eur, 2022 34 (60). https://doi.org/10.1186/s12302-022-00636-w
Benbrook C. “Missing the mark — new methods needed to detect and address high-risk pesticide residues in the global food supply,” Regul Toxicol Pharmacol. 2023 Feb;138:105328. DOI: 10.1016/j.yrtph.2022.105328 Epub 2023 Jan 2. PMID: 36603761
Benbrook, C., Kegley, S., & Baker. “Organic Farming Lessens Reliance on Pesticides and Promotes Public Health by Lowering Dietary Risks,” Agronomy, 2021, 11(7); DOI: 10.3390/agronomy11071266

For more information about the Pesticide Risk Tool
Meys, E. L., Mineau, P., Werts, P. Nelson, S.G.A. , Larson, A. & Hutchison, W.D. “Assessment of insecticide risk quantification methods: Introducing the Pesticide Risk Tool and its improvements over the Environmental Impact Quotient,” J. Integrated Pest Management, 2024,15 (1) https://doi.org/10.1093/jipm/pmad032