Stop the presses: we’ve come across a nuanced, thorough, and thought-provoking piece on Roundup and glyphosate.
No declarations that concerns about RoundUp are “anti-science” or that glyphosate is responsible for every chronic and autoimmune disease known to humankind.
- “Farmers have relied upon glyphosate-based herbicides to kill unwanted vegetation for more than four decades, but its use sparked hefty debate in 2015, when the World Health Organization’s International Agency for Research on Cancer (IARC) concluded that it was “probably carcinogenic,” adding it to a category that also contains red meat, for instance.”
- “Over the years, regulatory agencies have evaluated glyphosate’s potential effects on non-target organisms. However, recent assessments seem to be focused on carcinogenicity and genotoxicity of glyphosate, notes Deborah Kurrasch, a neuroscientist at the University of Calgary. Within the past decade, she says, evidence started to accumulate in the scientific literature that it might have other toxic effects. “There’s a lot of systems beside cancer” that can be affected, she says.”
- “Kurrasch, whose research is funded by the Natural Sciences and Engineering Research Council of Canada, began to look into glyphosate several years ago, and was surprised by how few studies there were in the literature. “There was very little for a chemical that we’re all exposed to,” she recounts, adding that there is still little known about its mechanism of action in model systems.”
- “Glyphosate is rarely used on its own in the field. Herbicide formulations as a whole include a variety of other chemicals, such as surfactants to help glyphosate enter plant cells, and other additives that extend the product’s shelf life. This spurred Kurrasch to compare the effects of glyphosate alone to the effects of Roundup (containing the same glyphosate concentration) in zebrafish. Remarkably, she found Roundup had the opposite effect as glyphosate by itself: The fish moved more, and basal respiration was higher. They also had different gene-expression profiles of mitochondria-linked genes in their brains. “It suggests that they have different mechanisms of action,” Kurrasch says, “that glyphosate is doing something and these adjuvants are doing something else.”
- “A problem for scientists investigating the physiological activities of pesticides is that herbicide-producing giants including Monsanto, Roundup’s developer, or Syngenta, which produces the glyphosate-containing herbicide Touchdown, aren’t required to make their full ingredients lists public. That makes it very difficult for a toxicologist to test the different ingredients to figure out what’s the most toxic, or what’s contributing to it,” says Vanessa Fitsanakis, a neurotoxicologist at Northeast Ohio Medical University.”
- “What concerns Fitsanakis, whose work is funded by the National Institutes of Health, are the findings of previous studies that the commercially available product is much more toxic to cells and animals in the lab than glyphosate alone. “The data are overwhelmingly in agreement that glyphosate by itself is relatively nontoxic,” she says.”
- “If there was a very obvious acute toxicity to . . . non-target organisms, one would think that that had been discovered by now,” says Peter Roslev, an environmental toxicologist from Denmark’s Aarborg University. “But you can only detect the effects that you are looking for, and that seems to be the history with many of these chemicals. There’s always an unexpected effect that nobody thought about, that this compound used for this purpose actually has this side effect,” he adds. “The truth is often not black and white,” he concludes in an email. “We therefore have an obvious responsibility as scientists to continue to screen for any overlooked side effects, because these chemicals are sold and used in vast amounts.”