Where does all the glyphosate go?

February 2012

Spraying crops in the evening dusk
Crop spraying. Photo by TaminaMiller on Flickr
“I think people haven't even thought or even looked at (glyphosate), because the advertising says it's such a safe product. Why do we even do the research?” (Dr. Don Huber)
Nearly four decades after the herbicide, glyphosate, first began to be sprayed on our environment, the search is still on for a fast, sensitive, reliable and accurate technique to measure it, even in water.

Glyphosate is the active ingredient of 'Roundup' herbicide now used on many Roundup-tolerant GM monocultures such as soya and maize.

This weed-killer is a challenging compound to detect because it can't be easily isolated from its background: glyphosate is a small molecule, highly soluble in water, it can behave as an acid or as a base (i.e. the distinctive properties often exploited to measure chemicals), and readily sticks to certain common materials such as metal ions and soil particles.

As the quantity of glyphosate applied grew exponentially over the years due primarily to the commercialisation of GM herbicide-tolerant crops, followed by the emergence of herbicide-tolerant weeds, has anyone been checking up on how much of the weed-killer there is all around us?

Look at the 'life-cycle' of glyphosate.

Farmers, gardeners, foresters, and road- and rail-maintenance teams all routinely use glyphosate. During use, the weed-killer is sprayed through the air onto vegetation which absorbs it, and what misses the plants lands on soil or in water.

After this, residues in the soil are assumed to be decomposed by microbes, while any residues in water just wash away, and scant attention is paid to the presence of the herbicide inside the plant,. The main derivative of glyphosate, AMPA (aminomethylphosphonic acid), is assumed to follow a similar fate once it forms. Do glyphosate and AMPA really vanish so readily?

In the soil, science has shown that half the glyphosate entering it can still be there over five months later. Such persistence shouldn't come as a surprise since the chemical is known to stick very firmly to soil particles; it's not going to go anywhere in a hurry. However, the microbial decomposition bit is wrong too. There are only a few organisms that can actually utilize glyphosate directly as a nutrient; most degradation is accidental and occurs when a microbe secretes an enzyme into its surroundings which happens to degrade the weed-killer.

The glyphosate absorbed by the plants certainly doesn't just disappear either: no plant, not even a GM one, has any ability to do anything except shunt the chemical to the growing points at the root- and shoot-tips, where it accumulates. Perennial crops will accumulate glyphosate year-on-year. From within the above-ground parts of the plant, glyphosate makes its way into food and feed and can end up who-knows-where. From the roots of the plants, glyphosate makes it way into the soil.

From the soil, wind erosion sends particles-plus-bound-glyphosate up into the air. This, and spray drift, have resulted in measurable glyphosate in both the air and in rain-water in GM crop-growing US states.

As for the glyphosate washed away in surface water, decomposition happens, but until the process is complete, it goes wherever the water goes. In the US mid-west GM-growing states, detectable levels of glyphosate or AMPA were found in up to 98% of surface water samples. In one grape-vine growing region in France, all but one surface water sample out of over 300 had detectable glyphosate. Ground water in areas used for intensive agriculture in Spain were found to be contaminated with glyphosate, some of which exceeded the limits set by the EU drinking water regulations. Glyphosate is also sprayed directly into some water-ways to clear them of weeds.

As a rising tide of clinical observations is demonstrating, humans in rural areas carelessly sprayed with glyphosate are suffering chromosome damage, cancers, fertility problems and many chronic diseases, with a huge toll falling on the children. In contrast to the exposure from this direct spray, the amounts of glyphosate and AMPA we're talking about in food, feed, air and ground water, are very small indeed. However, despite this, a recent German university study has revealed significant concentrations of glyphosate in the urine samples of city dwellers. The analysis of the urine samples found that all had concentrations of glyphosate at 5- to 20-fold the permitted limit for drinking water. The glyphosate out there is ending up inside us.

The problems are the unknowns:
  1. We don't know how much glyphosate we're actually being exposed to. Note that 'glyphosate is a challenging compound to detect' in even in water, and must be even more challenging to detect in living materials: we may have been underestimating its presence inside and around us for decades, and the environmental studies mentioned above were only published in 2011
  2. We don't know which sources of the glyphosate ingressing into our body (through food, drinking-water, washing-water, air, inhaled air, the placenta, or breast-milk?) might be particularly harmful.
  3. We don't know what the effects of chronic, low-level exposure to glyphosate and AMPA from multiple sources might be.
The latter concerns don't stem from any vague conviction about agri-chemical harm. Glyphosate binds strongly to metal ions. Such ions are vital for the action of many essential enzyme-driven biochemical processes in our bodies. To what extent trace amounts of glyphosate in key tissues will weaken our health and make us susceptible to disease is a serious question.

What's now becoming clear is that glyphosate's direct or indirect effects on the microbial flora outside in our environment and inside animals (including ourselves) are far from benign. Glyphosate selectively destroys 'good' microbes, leaving the pathogenic ones (normally suppressed by the 'good' ones) to flourish. Reports (going back a decade) of decreasing fertility in livestock are now being linked to a novel, malignant, self-replicating entity which also seems to be associated with glyphosate use. Cattle fed on GM feed (plus glyphosate) are suffering from premature aging such that the carcass of a 'prime' 2½-year-old can be down-graded to that of a 10-year old.

The reality we've created is that the nutritional 'value' of GM feed as judged by tried and tested (and likely out-dated) chemical analyses is fine, and the beasts feeding on the GM feed are growing as required, but something else very harmful is happening to them.


Dr. Don Huber, a US plant- and soil-pathologist and US Department of Agriculture adviser, has been trying to get the American regulators to hear the warnings from science about glyphosate. He is not anti-agrichemicals in the slightest, but refers to the weed-killer as “the most abused chemical we've ever had in the history of man”.

Huber has approached the US, UK*, and other EU governments to alert them. Ask your MP to make sure that this warning is heeded, that GM feed is removed from our food chain, and that GM food is not allowed to enter our food supply. And, once glyphosate is eliminated from our food chain, the government must monitor our environmental exposure levels, especially in children, no matter where we live.

*Dr. Don Huber spoke at a public meeting organised by the All Party Parliamentary Group on Agroecology and chaired by the Countess of Mar on 1st November 2011.


  • Interview with Dr. Don Huber by Dr. Mercola, Parts I and II,, January 2012
  • Dr. Eva Sirinathsinghji, Glyphosate Hazards to Crops, Soils, Animals and Consumers, Institute of Science in Society Report, 9.01.12
  • Marcela Valente, Poison from the Sky, IPS News, 9.12.11
  • Dr. Eva Sirinathsinghji, Pesticide Illnesses and GM Soybeans, Institute of Science in Society, 18.01.12
  • Backgrounder: Glyphosate and Water Quality, Monsanto, November 2003
  • GM Maizes Threaten EU Water - another reason to ban glyphosate, GM freeze Release, 11.01.12
  • J. Sanchis et al., 2011, 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, Anal. Bioanal.Chem., November
  • It's Official: Glyphosate used on GM crops found in US rivers, rainfall, GM Freeze Release, 31.08.11
  • Ken Roseboro, Roundup herbicide found in air, rain, and streams, The Organic & Non-GMO Report, 1.10.11
  • Richard H Coupe, et al., 2011, Fate and transport of glyphosate and aminomethylphosphonic acid in surface waters of agricultural basins, Society of Chemical Industry Pest Management Science Feng-chih Chang, 2011, Occurrence and fate of the herbicide glyphosate and its degradate aminomethylphosphonic acid in the atmosphere, Environmental Toxicology and Chemistry 30:3
  • Glyphosate General Fact Sheet, National Pesticide Information Center, Oregon State University
  • Now glyphosate found in people's urine, GM Watch reporting on
  •, 20 01.12
  • Marie Sonnegaard Poulsen et al., 2009, Modeling placental transport: Correlation of in vitro BeWo cell permeability and ex vivo human placental perfusion, Toxicology in Vitro 23


  1. The situation in the humid tropics is probably more serious than that in temperate agriculture where most of the research has been concentrated.Tropical soils are generally more acid and have more kaolinite especially those areas devoted to more permanent non-GMO crops such as oil palms, cocoa, bananos,coffee,tea and sugar cane among others. My worry is that all these crops are grown with the constant use of glyphosate year after year.The cheapest glyphosate analysis costs over $120 per sample. Don Huber is right.

  2. The use of glyphosate in the inner city after about 5 years of 3 times a year leads to low humus levels in soil and therefore low bacteria levels and therefore it takes a lot longer to breakdown in these humus poor clay/city soils.
    I live in Leicester and write the
    The soil has been eroded from around the base of the trees on the estate.

  3. GM crops are only a small part of the problem. Hardly anyone is talking about the much bigger problem - glyphosate used as a desiccant on EVERY seed crop that is not roundup ready GM. It is sprayed on wheat (flour), oats (oatmeal), rye, barley, beans, peanuts and sunflower seeds. Also sugar cane. Seed crops dry unevenly since there is genetic variation. If they are cut to dry they can get moldy if the weather is humid or rainy. Glyphosate causes the entire crop to die at one time and allows for the plants to dry out while standing, giving them better air flow and shortening the time before harvest. This happens a week before the seeds are processed for consumption by humans and farm animals. Every bread product, cereal, meat, dairy product, egg in the US has glyphosate from this process and has for 20 years. Check recommendations for harvest made by grain organizations like They mention that seeds to be used for next year's crop are not to be treated this way. They KNOW it persists in the seeds we are eating.

    1. I am a voracious reader and have never read that Glypho was used to kill crops and dry them out. This is diabolical The only way to protect ourselves is to reduce our consumption of food to the bare minimum of 900 calories per day.


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