Thanks for this! As a fellow scientist, you and I are on the same page. It drives me nuts the way EWG (and others, like Moms Across America) make up their own safe limits, pulling them out of thin air, rather than using the limits set by scientific and regulatory experts.
I tend to look at North American and EU and choose the most conservative one for my demonstration calculations. Right now Europe uses 0.5 mg/kg bw per day. US is reviewing glyphosate and seems poised to adjust to 1 mg/kg bw per day.
Here are my very similar calculations for a 60 kg adult at 0.5 mg/kg (using plain Cheerios — ~500 ppb).
- 60 kg x 0.5 mg/kg = 30 mg per day
- 30 mg / 0.5 mg/kg = 60 kg Cheerios
- This works out to 180 boxes (at about 3 boxes per kg) or 2,000 servings (30 grams per serving)
For my kids, I would divide by 2 based on my 8-year old son’s weight and by 4 for my 3 year old twins. I am most definitely not throwing out my Cheerios!
I am highly skeptical of the California safe limit. It claims to be science-based but when you look at the underlying data, they used a single series of rat experiments and tried to draw a curve using a single data point. It doesn’t take a mathematician to know this is shady business — talk about false precision! Furthermore, even over 2 years, they had to go to 1000 mg/kg per day to see anything!!
Table 1. Tumor incidences a of treatment-related lesions in male CD-1 mice administered glyphosate in the diet for two years (IARC, 2015; JMPR, 2006)
- 0 mg/kg/ day = 0/50 tumours
- 100 mg/kg/day = 0/50 tumours
- 300 mg/kg/day = 0/50 tumours
- 1000 mg/kg/day = 4/50 tumours
Here is a video version of my rant on this a few weeks ago!