So (I have not looked into it) are people experiencing serum glyphosate levels in this range of 1 ppm or higher, or even lets say 1/10th or 1/100th that amount, from consuming foods where Roundup was used agriculturally?
Apparently ( https://docs.google.com/viewer?a=v&q=cache:VMBJSdW_WAwJ:jat.oxfordjournals.org/content/27/3/162.full.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESh92mWrdNGWAxZxp1lg_m0Jh4yLFlTWtzqoAlUNguR4bxJIPTZWeiIU2JgpehinGggkP7mrVlWZwISeXzz6T3HbpH3jDJZrqIrbAJs84tXo2HmbZxXItsgYlLHY_5UhEzkpNHg9&sig=AHIEtbTRYS8ER3iQdRAkxBCdPIvk3QhrcA ) drinking 100 mL of glyphosate herbicide, not necessarily Roundup, in a suicide attempt gave a serum level of about 4400 ppm glyphosate. So the 10,000 ppm end of the study range seems a little excessive. They did however see substantial effect at 1 ppm also. On a quick check, I didn't see evidence as to whether people are experiencing blood levels on the order of 1 ppm, or 1/100th of that, or any particular value as a result of these herbicides being used agriculturally.
An expectation that an herbicide or pesticide be completely non-toxic to humans even at concentrations far beyond what anyone would get from consuming the foods is probably unrealistic, unless wishing to accept our food supply decreasing drastically. So the question is, is the 1 ppm level, or anything like it, remotely relevant to amounts actually resulting in humans? Short of being careless with the stuff, or perhaps being exposed by aerial spraying, etc., which could be a different issue.