If you spend time understanding the science behind Roundup and glyphosate, it’s active ingredient, you soon realize that this is a safe chemical compared to many other chemicals, even ones liberally used in the home. Why is it then that so many people fear Roundup?

Probably the biggest reason is great promotion by the anti-Roundup and anti-Monsanto crowd. That is one powerful force, that brings one misleading article after another to the attention of a lot of people.

I think that another reason for this fear is our inability to understand very small and very large numbers. A recent research study found glyphosate in natural water systems and I have seen it posted by several people as proof of a real problem that needs to be feared. If these people simply understood small numbers, they would not fear the report or Roundup.

Glyphosate in Our Water

A recent study (ref 1) found that 41% of the 140 ground water samples tested in Spain contained glyphosate.

The abstract title is “Determination of glyphosate in groundwater samples using an ultrasensitive immunoassay and confirmation by on-line solid-phase extraction followed by liquid chromatography coupled to tandem mass spectrometry.”

The author of the quoted reference took the data of the study and came up with this title, “Glyphosate, despite its low mobility in soils, is capable of reaching groundwater. 41% of 140 groundwater samples from Catalonia, Spain contained high levels, technically beyond the limit of quantification.” Note the “contained high levels, technically beyond the limit of quantification”

The levels are in the ng/L range – that is not high levels.

What does “technically beyond the limit of quantification” mean? It certainly does not mean the levels were too high to measure – you simply dilute the sample. And if the levels were so low they could not be detected – then they are certainly not high levels.

More gobbledygook to help convince people of the terrors of glyphosate.

They did find glyphosate in 41% of the samples. That means 59% had no glyphosate – a much more positive way to report things.

I don’t have the actual paper, only the abstract, but that is enough for this discussion. I’ll assume the work was well done, and the data is accurate.

Understanding Small Numbers

The average glyphosate in the 41% of positive samples, was 200 ng/L. A number like 200 sounds like a lot and we humans really can’t visualize a ng (nano-gram), so this seems like a lot. But how much is it?

200 ng/L = 0.000,000,2 g/L

You might know that a gram is about the weight of a paperclip, but that does not really help to understand this number because it is so small.

“The EPA Allowable Daily Intake (ADI) for glyphosate is set at 1,750 µg (1.75 mg) per kg of body weight. The EU ADI is just 0.3 mg per kg body weight.” (ref 2). I’ll go with an average of 1mg/Kg.

The daily safe intake for someone weighing 70 Kg (150 pounds) is 70 mg. If you were drinking the average contaminated water in Spain you would need to drink 350,000 L before you would reach this safe level. Or putting it in terms everyone understands – 1,000,000 bottles of good Canadian beer. And that is the daily allowance.

What About The Water?

The above calculation is informative, but I left out one very important detail. Water is also toxic. I found an MSDS (material safety data sheet) (ref 3) showing an LD50 of >90 mL/Kg for water.

The 70 Kg person discussed above would have a 50% chance of dying after drinking just 6.3 L of water. They would almost certainly be dead long before they could drink the 350,000 L of glyphosate-laced water from Spain.

Interesting, probably only to a biochemist, is the fact that water would never kill you. By drinking water your body would get its sodium/potassium levels out of wack and that kills you. The water itself is not toxic.

References:

1. Glyphosate is capable of reaching groundwater; http://www.greenmedinfo.com/article/glyphosate-despite-its-low-mobility-soils-capable-reaching-groundwater-41-140-groundwater
2. Glyphosate Levels in Breakfast Foods: What is safe?; http://www.anh-usa.org/glyphosate-breakfast-report/
3. MSDS for Water; https://www.ch.ntu.edu.tw/~genchem99/msds/exp26/water.pdf
4.  Photo Source; Aqua Mechanical (photo modified)