Persistence of Roundup in soil:
"Field studies cited in the report show the half-life of glyphosate in soil ranges between a few days to several months, or even a year, depending on soil composition. The authors say the research demonstrates that soil sorption and degradation of glyphosate vary significantly depending on the soil’s physical, chemical, and biological properties."
https://www.chemistryworld.com/news/glyphosate-persistence-raises-questions/9510.article
Sounds good to me, days to months, and not more than a year (and what % makes it past months?).
Sometimes results tell us a lot more than raw analysis - in this case, an org with some fairly obvious bias (which is OK, just take it into consideration), found levels ~ 1 ppM (and you know they were looking for the highest they could), and that results in the extremely low concerns that I pointed out. The studies couldn't really make a connection based on consumption levels of 4,000x their body weight in oat cereal, per day!
Let's try the math again, the studies were around 4,000mg/kg bw/day. So for an 80 kg human, that's 320 grams/day. A quick search brought up a wide range of numbers for pounds of food a person eats a day, but I'll go with ~ 5 lbs, and round to 2.5 kg. So 320/2500 = 0.128 which is 128,000 ppM (give or take).
And you really think we should be worried about an occasional 1 ppM in a portion of our food that we probably don't even eat every day? Like I said, if you are that concerned, you better do a deep dive into everything you eat, drink, or are exposed to. Being 'natural' is no assurance of safety (why do avoid lead, arsenic, poison mushrooms, black widow spiders, etc?).
edit/add: 320 grams is almost half a cup! Can you imagine drinking 1/2 cup of RoundUp right out the package, every single day for years! Geez, I bet there are lots of things we could not consume that much of w/o ill effects, and we don't even think about it. Some perspective is needed!
-ERD50