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A pre-harvest spray, probably of a glyphosate-based weed-killer, is applied to an oilseed rape (canola) crop in Occold, Norfolk. Photo: Tim Parkinson via Flickr (CC BY).
A pre-harvest spray, probably of a glyphosate-based weed-killer, is applied to an oilseed rape (canola) crop in Occold, Norfolk. Photo: Tim Parkinson via Flickr (CC BY).
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Keep glyphosate out of our food!

Peter Melchett

3rd September 2015

Following scientific confirmation of the severe hazards to health caused by residues of glyphosate weed killers in food, the Soil Association is calling on bakers and retailers to stop 'pre-harvest' spraying on arable crops. The SA's Peter Melchett just sent out this letter - adapt as necessary and send to retailers, bakers, makers of cereals, pasta, biscuits and others.

The ultra-low doses of Roundup investigated, and the negative impacts on human health identified, make any reliance on the existing Maximum Residue Level for glyphosate both redundant and potentially dangerous.

Dear bread manufacturer or retailer,

I am writing to you to follow up the letter I sent in July about the World Health Organisation's Committee's finding that glyphosate is a probable carcinogen to humans.

I'm grateful to Tesco, Sansbury's, Waitrose, Co-op, Warburtons, the National Association of British and Irish Millers and Allied Mills for their replies to my letter or their comments on it, and I am looking forward to our meeting with the Federation of Bakers in early September.

The main response made by industry spokespeople to the International Agency for Research on Cancer (IARC) has been to say that while it is clear that up to a third of samples of UK bread tested by the Department for Environment, Food and Rural Affairs' Expert Committee on Pesticide Residues in Food (PRiF) contain glyphosate, glyphosate is present below the Maximum Residue Level, and therefore should not be of concern to your customers.

As many scientists have pointed out, there has been long-standing scientific concern that glyphosate can have negative impacts on human health at well below the MRL, and that it may act as a hormone disrupter, and there is therefore unlikely to be a level at which glyphosate can be safely eaten in bread. This is because hormone disrupting chemicals can have an impact on human health at extremely low doses.

Since I last wrote to you, two new scientific papers have been published which support previous scientific concerns that there are no levels below which glyphosate can be safely eaten in bread.

Damaging alterations in gene function at

The first paper 'Transcriptome analysis reflects rat liver and kidney damage following chronic ultra-low dose Roundup exposure' (2015 Environ Health, 2015 Aug 25; 14(1): 70. doi: 10.1186/s12940-015-0056-1) concludes:

"A distinct and consistent alteration in the pattern of gene expression was found in both the liver and kidneys of the Roundup treatment group ... these alterations in gene function were consistent with fibrosis (scarring), necrosis (areas of dead tissue), phospholipidosis (disturbed fat metabolism) and damage to mitochondria (the centres of respiration in cells." [Note: Roundup is Monsanto's proprietary glyphosate herbicide product.]

Over 4,000 genes were affected in the Roundup treatment group, with either increased or decreased activity (expression).  The glyphosate equivalent dose of Roundup administered in this study is what may be found in drinking water (the levels investigated were half that permitted in drinking water in the European Union).

Moreover the amount of glyphosate-equivalent Roundup consumed by the research animals on a daily basis was many thousands of times below the regulatory set safety limits of glyphosate alone.

The lead scientist, Dr Michael Antoniou of Kings College said: "The findings of our study are very worrying as they confirm that a very low level of consumption of Roundup weedkiller over the long term can result in liver and kidney damage. Our results also suggest that regulators should re-consider the safety evaluation of glyphosate-based herbicides."

Liver and kidney damage at ultra-low environmental doses

The second paper, 'Potential toxic effects of glyphosate and its commercial formulations below regulatory limits', concludes:

"Our results suggest that chronic exposure to a GBH [Glyphosate-based herbicide] in an established laboratory animal toxicity model system at an ultra-low, environmental dose can result in liver and kidney damage with potential significant health implications for animal and human populations."

The study highlights toxic effects below regulatory limits, in around 30 studies, including studies performed by chemical companies on their own products. This new study also looked at the impact of Roundup at a concentration of 0.1 parts per billion, with a glyphosate concentration which was half the concentration in drinking water allowed by the European Union (which is 0.1 μg/L):

"The results showed that Roundup caused an increased incidence of anatomical signs of pathologies, as well as changes in urine and blood biochemical parameters suggestive of liver and kidney functional insufficiency in both sexes."

The scientists say that their results suggest that further research is needed "to evaluate the endocrine disruptive capability of glyphosate-based herbicides."

They add that "It was previously known that glyphosate consumption in water above authorized limits may provoke kidney failure and reproductive difficulties. The results of the study presented here indicate that consumption of far lower levels of a GBH formulation, at admissible glyphosate-equivalent concentrations, are associated with wide-scale alterations of the liver and kidney transcriptome that correlate with the observed signs of hepatic and kidney anatomorphological and biochemical pathological changes in these organs."

Any reliance on the current MRL is potentially dangerous

The Soil Association believes that the ultra-low doses of Roundup investigated by these two new pieces of scientific research, and the negative impacts on human health identified, make any reliance on the existing MRL for glyphosate both redundant and potentially dangerous.

The only responsible course for any retailer, manufacturer or miller must be to eliminate exposure to glyphosate from eating British bread.

The main route of exposure: pre-harvest herbicide application

As you know, because we do not currently have any GM crops that are resistant to Roundup grown in the UK, the main source of glyphosate in British flour and bread comes from the practice of farmers spraying Roundup and other glyphosate-containing weed killers on wheat crops a few days before they are harvested.

The August edition of an East Anglian farming magazine contains an article in which Monsanto say that "Roundup is particularly useful" on later-maturing varieties of wheat even when grain is dry enough to combine. Farmers are being told in this article that spraying with Roundup will speed up their harvest, and give them a drier grain sample.

However, it is clear that the use of Roundup immediately before harvest is mainly a matter of convenience for farmers, and not a necessity.

Indeed, there are already concerns about the possibility of Roundup-resistant weeds arriving in the UK (they are now a major nuisance for US farmers), with the Agriculture and Horticulture Development Board warning of "the threat of glyphosate-resistant weeds, and the associated economic consequences."

In the light of this new scientific evidence, published over the last few days, which confirms previous concerns about the impact of very low doses of glyphosate on human health, the Soil Association is again urging you to ensure that none of the flour or bread products you manufacture or sell to British people contains any glyphosate at all.

In view of the serious human health implications of these two new scientific studies, the Soil Association is making this letter available to the public.



Peter Melchett is Policy Director at the Soil Association.

Campaign: Peter invites food campaigners to adapt this letter to send to the consumer affairs departments of other food companies that may be providing food containing glyphosate residues, and send it under their own names.

While the SA's current campaign focuses on bread, other companies to press on the issue include those making or retailing breakfast cereals, oatmeal, biscuits, pasta, baked foods, vegetable oils, mushy peas and other products.

Backgound information: the UK licences the use of glyphosate-based herbicides on a variety of arable crops. For example, Monsanto's 'Roundup with MAPP Number 12645' is licenced for use on wheat, barley, oats, durum wheat, combining pea and field bean, just seven days before harvest. It can also be used on oilseed rape and linseed 14 days before harvest and on mustard crops eight days before harvest.

Also on The Ecologist: 'Keep health-damaging weed killer out of our bread!'


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