You can say likewise about any other pesticide on that basis.. but I do wonder where the "hundreds of thousands of tonnes" comes from. My farm applies 540 grams

You can say likewise about any other pesticide on that basis.. but I do wonder where the "hundreds of thousands of tonnes" comes from. My farm applies 540 grams of glyphosate per acre on our soybean crop each season.. if that is applied to every acre of farmland in the USA that would be 500mt of glyphosate. So you believe that a majority of the acres in the USA have at least 540g/ac applied and that a majority of that glyphosate is not metabolized by plants but is mobile in runoff? I would be extremely interested in the research that validates that because it is not consistent with my experience.