On October 30, 2020 Dr. Benbrook testified via video to the Philadelphia City Council in support of a proposed municipal ban on herbicide application in city parks and other public lands.
His written statement accompanying this testimony is shared in its entirety below. It reviews the key public health implications of rising herbicide use for the Council’s consideration.
Statement of Charles Benbrook, PhD
The Heartland Study
“Healthy Outdoor Public Spaces Bill” (# 200425)
Accompanies Testimony Delivered Before the Health and Human Services Committee
Philadelphia City Council
Tuesday, October 13, 2020
Honorable Chair and Members of the Committee on Health and Human Services, I appreciate the chance to explain some of the benefits for the City of Philadelphia if this bill is passed and thoughtfully implemented. But first, let me summarize my experience and scientific work on the use of Roundup and other glyphosate-based herbicides (GBHs).
The fraudulent chronic testing of glyphosate in the 1970s by a contract lab called IBT became a major issue for the federal EPA, since the Agency had approved dozens of uses of Roundup in the absence of a single, valid chronic study. Back then, I worked as the Staff Director of the House Subcommittee with jurisdiction over the national pesticide law (FIFRA). We spent considerable time over two years trying to understand how and why the IBT debacle occurred, and what the EPA and the pesticide industry needed to do in response.
I have studied and published many reports and peer-reviewed papers on changes in the use of Roundup and GBHs, GBH regulation, and the health and environmental impacts arising from GBH use. These include papers I co-authored with other scientists on the toxicological and human health risks arising in the wake of heavy use of GBHs.
Glyphosate Use
My 2012 paper in the peer-reviewed journal Environmental Sciences Europe quantified the impact of genetically engineered, Roundup Ready crops on pesticide use in the US . It has been downloaded over 299,000 times, and is the most heavily accessed paper in the 20+ year history of the journal.
My 2016 paper on changes in US and global GBH use over the last 40+ years documents the meteoric rise in farmer reliance on glyphosate and GBHs starting in the late 1990s. According to the journal, “This article is in the 99th percentile (ranked 82nd) of the 345,503 tracked articles of a similar age in all journals.”
This GBH use paper is the source of statistics you may have encountered — enough glyphosate is applied annually in the US to spray about three-quarters of a pound of glyphosate on every acre of harvested cropland in the US. Globally, enough glyphosate is sprayed every year to apply about two-thirds of a pound of glyphosate on every actively farmed acre on the planet.
For over a decade, glyphosate has been by far the most heavily applied pesticide in history. Several serious problems have arisen more so from how widely GBHs have been used — and overused — than from glyphosate’s innate mammalian toxicity. These include:
- The global spread of dozens of glyphosate-resistant weeds that are now driving overall herbicide use upward;
- Adverse impacts on pollinators and biodiversity, soil health, and water quality and aquatic ecosystems;
- The development of non-Hodgkin lymphoma; and
- Possible contributions to other health risks including other cancers, GI tract problems, liver and kidney diseases, and adverse birth outcomes among heavily exposed rural populations and applicators (even here in the City of Brotherly Love).
IARC vs. EPA on Glyphosate Oncogenicity
In 2015, EPA concluded pure glyphosate was “unlikely to be carcinogenic in humans,” while the International Agency for Research on Cancer (IARC) classified glyphosate and GBHS as “probable human carcinogens.” How two institutions with access to world-class scientific expertise could reach such different conclusions has been, and will remain the #1 debate throughout the Roundup-NHL litigation.
I published a widely read, open-access paper in 2019 reporting on the way the US EPA and IARC assessed the genotoxicity of glyphosate and GBHs. Its title frames its relevance in the EPA vs. IARC debate: “How did the US EPA and IARC reach diametrically opposed conclusions on the genotoxicity of glyphosate-based herbicides?”
This 2019 paper explains that EPA and IARC relied on very different sets of glyphosate and GBH genotoxicity studies. EPA focused almost exclusively on proprietary, unpublished genotoxicity assays conducted by Monsanto and other GBH registrants. Only one of 95 of the registrant-conducted assays were positive for genotoxicity (1%).
IARC based its assessment of glyphosate and GBH genotoxicity on published, peer-reviewed studies encompassing 122 assays, of which 89 were positive for genotoxicity (73%). IARC placed heavy weight on five key studies in exposed human populations (four positive); EPA largely ignored them.
The most recent genotoxicity study considered by EPA and IARC at the time they classified glyphosate and GBHs with respect to cancer was published in January 2015. Between then and the end of 2018, at least 27 additional peer-reviewed studies were published (Table 4 in my paper lists them all). Twenty-six of the 27 new studies reported one or more positive genotoxicity assays. Since the end of 2018, several more glyphosate and GBH genotoxicity assays have been published, the vast majority of which has also been positive.
You can access my glyphosate and GBH papers on my website, Hygeia Analytics.
Roundup’s Role in Non-Hodgkin Lymphoma
Over the last four years, I have served as an expert witness on behalf of plaintiffs in the litigation involving the possible connections between Roundup use and exposures and non-Hodgkin lymphoma (NHL). My work on the litigation has allowed me access to the 8-plus million documents in the confidential discovery record. I have reviewed thousands of internal Monsanto emails, documents, reports, and data spanning the late 1970s through 2019.
While I have paid close attention over 40 years to all key events in the regulatory history, use, and testing of glyphosate and Roundup, I was shocked repeatedly as I read internal company documents, many of which are now in the public domain, setting forth what Monsanto knew decades ago about the risks associated with heavy worker exposures to Roundup, and what they did, and did not do in response to that knowledge.
The Core Paradox of Roundup
Roundup was once the most effective herbicide ever discovered, and one of the least toxic to mammals. It is a shame, indeed tragic, that it has been marketed and regulated in ways leading to grossly excessive use, and sometimes dangerous levels of human exposures.
As a result, there are now over two dozen weeds that have become resistant to glyphosate, and tens of thousands of people here in the US, and an unknown but no doubt much larger number globally, who have battled non-Hodgkin lymphoma that was either triggered, or made worse and harder to treat, by high and/or repeated exposures to glyphosate during applications of Roundup.
Since the early 1980s, Monsanto has successfully kept regulators, the scientific community, and Roundup users largely in the dark regarding the human health risks facing applicators. Individuals spraying Roundup frequently, for several hours per day over a number of years, face the greatest risks, and likely include some employees in the Philadelphia parks department.
Definitive information surfaced during the litigation that shows that urban and suburban applications of Roundup by people using handheld or backpack sprayers lead to much higher dermal exposures than those experienced on the farm. It also became clear that glyphosate exposures to the general public via their diets are a small fraction of the exposure a person might get from just one hour of spraying a GBH with a handheld applicator.
A worker in the Philadelphia parks department assigned to weed management duties during the spring and through mid-summer might typically spray herbicides for 2 to 6 hours per day, for 3-4 days per week for about 4 months. As part of their job, such a person might engage in 100 hours, to as many as 300 hours applying herbicides in a calendar year.
On some of those days, and during a few applications, things will not go exactly perfectly. For example: less than perfect weather conditions (aka wind), more mature weeds needing a heavier rate of application, a leaky hand wand, a spill when loading the sprayer tank, and/or a leaky hose or value can lead to significant exposure episodes.
For people that spray herbicides as part of their jobs using handheld equipment, it is very hard to avoid a few such episodes every year. For most of these applicators, there will be one or a few very-high exposure episodes every few years, even among those individuals who are careful.
Most plaintiffs in the Roundup-NHL litigation recalled several days when they were heavily exposed, to the point, for example, where pant legs were soaked through, hands were covered for hours, or the herbicide had soaked through much of their clothing.
It is this sort of high exposure scenario that can turn a relatively safe herbicide like Roundup into a potential cause of significant harm to people’s health.
As herbicides are currently used in Philadelphia, applicators are at the greatest risk, but members of the public using public spaces soon after applications can also be exposed at levels sufficient to pose heightened risks, especially among vulnerable segments of the population. Those potentially more vulnerable include:
- Individuals currently battling cancer,
- People administered drugs that suppress the immune system,
- Women planning on becoming pregnant, or pregnant,
- Young children, and
- Anyone with an infection or health condition that lessens the capacity of their immune system to deal immediately and effectively with aberrant cell growths that can progress to cancer.
In short, a lot of people.
I support passage of the “Healthy Outdoor Public Spaces Bill” because there are ample effective, affordable, and safer ways to manage weeds in Philadelphia including mowing, hoeing and hand weeding, weed whacking, tilling, and mulching. Plus, citizens in Philadelphia can share the city’s public spaces with a few weeds here and there without appreciable inconvenience or aesthetic sacrifice.
As the City invests in non-chemical pest management practices and strategies, their effectiveness will incrementally rise, and their costs will fall as city employees master the science and art of non-chemical control strategies.
In addition, the private sector is beginning to invest serious capital in the discovery and commercialization of new tools, machines, equipment, monitoring methods, and biopesticides. The surest way to encourage such investments, and speed positive technological change, is to support those companies and service providers working to make pest management simpler, safer, and more reliable.
If the City were to continue relying predominantly on herbicides in managing weeds, the collateral damage will incrementally rise, and the number of high-exposure episodes among City employees and members of the public will invariably increase. At some point in the future, the City will likely have to defend its decision to use herbicides in a court of law. As other jurisdictions have learned, the cost of even one pesticide-human health lawsuit can approach, or even exceed the entire budget dedicated to Philadelphia‘s weed management program.
Our national nightmare with Covid will hopefully deepen appreciation of what it takes to keep people safe, not just in a single apartment or a house in the suburbs, but in large, vibrant, and diverse metropolitan areas. Many Covid-inspired lessons will apply to how both individuals and societies deal with pests, from the coronavirus to ants and roaches, mice and rats, and pigweed and dandelions. Perfecting how to control weeds in cities without herbicides is one of many small steps that will collectively enhance environmental quality, biodiversity, and wellness and well-being inside city limits.
Thanks for the opportunity to share these thoughts with you. I am glad to answer any questions you have.