Dr. Charles (Chuck) Benbrook has spent the past 40 years trying to understand how farming systems impact food and health. He recently wrote a paper with Dr. Susan Kegley and Dr. Brian Baker comparing pesticide use and risk between organic and conventional farming systems. Dr. Benbrook joined OPN to discuss the key findings in the just-published paper “Organic Farming Lessens Reliance on Pesticides and Promotes Public Health by Lowering Dietary Risks,” which appears in the journal Agronomy and is open access (free to anyone).
Dr. Charles (Chuck) Benbrook, Executive Director, Heartland Health Research Alliance
What are the paper’s major findings on pesticide use?
Organic farmers use essentially no herbicides. Herbicide use accounts for over one half of all pesticide use in the US, which is a consequential difference.
All the pesticides approved for use on organic farms are exempt from a tolerance requirement except one–Spinosad. Why? Because the majority [of pesticides approved for organic use] pose no dietary risk. Forty-four do not even have to be registered by the EPA because they pose essentially no risk to non-target organisms, including people.
Between 1992 and 2019, the pounds of herbicides applied on conventional farms was up 48 percent. Insecticide use has tripled because of the Bt toxins produced by GMO corn and cotton crops, and total pesticide use is up 60 percent. The spread of serious herbicide-resistant weeds is driving herbicide use and costs upward coast to coast, with no end in sight.
What about pesticide residues in food and dietary risks? Any new insights?
This paper breaks a lot of new ground. For the first time, we report that fruits and vegetables account for about 98-percent of total dietary risks across the food supply.
In 2019, the average sample of five fruit products tested by USDA contained 3.15 pesticide residues, and five vegetables contained 2.6 on average. Residues were far less common in organic food, averaging 0.29 in fruit and 0.75 residue per sample of vegetables (for fruits, approximately 71 percent had no residues, 29 percent did). A person consuming 4-5 servings of conventional produce a day is almost certainly ingesting over 10 different pesticide residues day in and day out. This is NOT OK, especially for pregnant women, infants, and children.
In terms of dietary risk across five vegetables tested by USDA, conventional produce posed over 50 times the average dietary risk in the corresponding organic vegetables. In five fruits, the average differences were even greater, over 100-fold.
Does the paper offer insights on how pest management is holding back farmers from transitioning to organic?
Yes. We discuss several constraints including the limited supply of appropriate machinery, and especially small-scale machines and implements, and the lack of and/or high cost of essential inputs—from biopesticides to compost to seeds.
Another key issue is the grossly inadequate public investment in science, technology, and technical assistance for farmers thinking about making the plunge.
"We discuss several constraints including the limited supply of appropriate machinery, and especially small-scale machines and implements, and the lack of and/or high cost of essential inputs—from biopesticides to compost to seeds." – Chuck Benbrook
Perhaps the most important barrier is the government’s systemic suppression of information documenting the significant health and environmental benefits of organic farming.
Do you offer any recommendations to help ease the transition to organic?
We highlight the fact that fruit and vegetable production accounts for just 1.2 percent of the harvested cropland in the US yet leads to nearly all pesticide dietary risk as well as a high percent of applicator and farmworker poisonings.
Among our conclusions, we write: "The technology and systems are accessible or within reach over the next decade to support a successful shift to organic management of nearly all acreage growing fruits and vegetables in the US."
Three things stand in the way of this highly desirable outcome—the lack of market opportunities, marketing infrastructure, and inadequate demand. The next wave of organic growth will come from people learning more about the nutritional quality and the pesticide risk posed by the foods they buy and consume.
“The next wave of organic growth will come from people learning more about the nutritional quality and the pesticide risk posed by the foods they buy and consume.” – Chuck Benbrook
Current trends in conventional agriculture are likely to prove difficult to change. In the interim, organic farmers will continue to perfect alternative methods to enhance soil health and manage complex, biologically diverse systems.
How will you share results from this paper and advocate for an accelerated shift to organic growing practices?
New data on food pesticide residues comes out regularly from USDA and the UK Food Standards Agency. We will use this data to keep cranking out results via our Dietary Risk Index system on Hygeia Analytics and will share new insights with everyone willing to listen.
I am looking forward to interacting with growers and everyone in the produce supply chain at OPN’s Organic Grower Summit this December in Monterey. I am excited to share our work with CCOF and other certifiers to develop systems that extract more value from the NOP-mandated residue testing they perform.