Proof continues to mount that the use of glyphosate herbicide in agriculture and landscape weed control poses no danger to humans, the claims of covetous plaintiffs’ attorneys notwithstanding. Glyphosate is the compound in Roundup and Spectrum weed killers. Ag Daily summarizes the EPA’s 10-year review of the empirical evidence in “EPA reaffirms no human health risk from glyphosate has been found“. The article notes that glyphosate has been studied extensively around the globe:

“The bodies supporting these safety findings include the European Food Safety Authority, European Chemicals Agency, German BfR, and Australian, Canadian, Korean, New Zealand and Japanese regulatory authorities, as well as the Joint FAO/WHO Meeting on Pesticide Residues.“

I should make one qualification about the EPAs findings: they apply to registered uses, and not to improper application or exposure to more than the prescribed use of glyphosate. Evidence that excessive exposure is dangerous is not in doubt, yet such findings are routinely presented as if they apply generally. This article in The Scientist makes clear that there are number of pathways along which glyphosate might be harmful to humans and animals (like anything else, really), but the evidence of those effects is mixed, at best, and limited to unrealistic conditions. Glyphosate, the so-called active ingredient, is heavily diluted for application, so it is correctly used in minute quantities. It is always important to follow the manufacturer’s instructions for use, wear appropriate protective gear, and in the kitchen, rinse your produce thoroughly just to be safe.

It’s also important to note that in terms of toxicity, glyphosate is benign relative to the herbicides it replaced, a process that accelerated in the 1990s. Michelle Miller describes a basic relation that is critical to understanding the real dangers posed by any natural or manufactured substance: Risk = Hazard + Exposure. So-called “natural” herbicides used on organic farms are often applied heavily due to their relative inefficacy, so heavier exposure to those herbicides may well offset the presumed health advantages of organic foods.

Glyphosate has additional advantages: it minimizes tillage of fields, which reduces the energy-intensity of farming and avoids unnecessary microbial disturbance, thereby reducing emissions of methane, nitrous oxide, and CO2. It also improves farm yields, helping farms prosper and enhancing the world’s food supplies.