26
Oct
Common Herbicide Contributes to Development of Inflammatory Bowel Disease
(Beyond Pesticides, October 26, 2022) Inflammatory bowel disease (IBD) may be exacerbated by exposure to the herbicide propyzamide, used in both agriculture and on ornamental lawns and landscapes, according to research published in the journal Nature this month. As the rate of autoimmune diseases continues to increase rapidly in the U.S. and the world, it is critical for scientists to better understand the etiology behind these diseases and the environmental factors contributing to their development. Recent data show that the number of people living with Crohn’s disease and ulcerative colitis, common types of IBD, have risen annually by 3.4% and 2.8% respectively, between just the years 2001 to 2018. “As we learn more about the environmental factors that might contribute to disease, we can develop state- and national-level strategies to limit exposures,” said study coauthor Francisco Quintana, PhD. “Some chemicals don’t seem to be toxic when tested under basic conditions, but we do not yet know about the effect of chronic, low-level exposures over decades, or early-on in development.”
Researchers did not begin their study investigating propyzamide. Initial intent focused on better understanding environmental factors that may be contributing to IBD. Using a range of different models, scientists cross-referenced data from the U.S. Environmental Protection Agency’s ToxCast database to screen hundreds of different chemicals that had an affect on intestinal inflammation. Ultimately, 20 candidate chemicals were found, and scientists decided to focus on propyzamide due to its broad use patterns in food and in residential areas.
Using a mouse model, scientists found that propyzamide worsened an inflammatory process that had already been triggered by another exposure, but did not initiate the inflammation. Subsequent RNA sequencing confirmed an up-regulation of inflammatory pathways in the presence of propyzamide. Further modeling reveals that propyzamide boosts inflammation by interfering with signaling by aryl hydrocarbon receptors (AHR), a protein that codes for immune response and detoxification, and thus works to reduce bodily inflammation.
“Our methodology allowed us to identify a chemical that disrupts one of the body’s natural ‘brakes’ on inflammation,” said Dr. Quintana. “This method can identify new chemical candidates for epidemiological studies, as well as novel mechanisms that regulate autoimmune responses. In addition, this platform can also be used to screen and design for therapeutic anti-inflammatory drugs.”
The authors note that in the United States, the levels of propyzamide estimated by EPA to be present in surface and groundwater are concerning and similar to the rate at which adverse effects are seen for other common environmental contaminants like benzene, toluene, and certain phthalates. “Exposure levels to propyzamide would be expected to be much greater in communities in which higher levels of ground water contamination can occur from propyzamide use, as well as for people working in the agricultural sector who would be more directly exposed on a regular basis,” the study notes.
Researchers indicate that real-world data from disproportionately affected communities could help further explain the etiology of IBD. “Future studies should determine actual exposure levels in communities with potential high exposure to propyzamide and among agricultural workers, and determine whether other environmental, microbiome and genetic factors synergize with propyzamide during the pathogenesis of IBD,” the authors wrote.
While IBD has long been long viewed as a disease most prevalent in western nations, recent evidence indicates that the prevalence is rising rapidly in newly industrialized countries in South America, Asia, and Africa. The continued rise of autoimmune and nervous system disorders among the residents of industrialized nations should be a warning sign for other countries looking to U.S. chemical-based agricultural production as a model for development.
While the European Union is looking to address the rampant use of pesticides linked to public health and biodiversity declines, officials in the U.S. are working against this initiative at the behest of agrichemical industry interests. Instead of turning away from chemicals like propyzamide that are associated with autoimmune disorders, the U.S. is working to bring more countries into our unsustainable and ultimately self-defeating method of food production.
Stop the use of propyzamide and other toxic pesticides in your community by promoting alternative organic approaches, and eating organic food whenever possible. Act now to tell your local leaders to transition your public parks to organic management. And for more information on the link between pesticides and autoimmune disorders, see the page on Immune System Disorders in Beyond Pesticides’ Pesticide Induced Diseases Database.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source: Nature, Brigham and Women’s Hospital press release
what is/are the trade name for propyzamide? For what is it’s labeled use and how is it most commonly used?
November 3rd, 2022 at 8:50 am