Glyphosate, the world’s most widely used herbicide, is becoming a major health concern following the publication of a study by the World Health Organisation (WHO) last year which concluded it is ‘probably’ carcinogenic. A further study in the US has found traces of glyphosate in people’s urine, which supports the findings of a Friends of the Earth study from 2013.

Glyphosate’s license in the EU runs out on 30 June and Italy, France, Sweden and the Netherlands forced the postponement of a decision back in March by the European Commission to re-license it. A compromise proposal of a temporary license extension of 12-18 months also failed to win majority support. A recall of Monsanto’s Roundup and other weed killers looks likely if no decision is made by the end of the month.

The Sustainable Food Trust’s Chief Executive, Patrick Holden, and Policy Director, Richard Young, discuss the likelihood of an EU ban and how this might impact agriculture.

What is the justification for banning Glyphosate?

Richard: Glyphosate has been promoted as a completely safe product and it’s come to be the most widely used herbicide in the world, not just in agriculture, but in gardens and public parks too. Unlike selective herbicides, which just kill the green growth above ground of specific weed species, glyphosate has a broad spectrum effect, killing all green crops and weeds including their root systems. This has enabled farmers to control perennial weeds without use of a plough. As a result, farming systems have developed which depend on glyphosate, in particular roundup ready GM crops, but also most minimum tillage systems. For a long time there has been mounting evidence to suggest a wide range of potential environmental and health problems associated with glyphosate, and the WHO has now listed it as a probable carcinogen because many studies have linked its use to the cancer non-Hodgkin’s lymphoma. There are also concerns that glyphosate has been shown to have an antimicrobial effect and can actually cause antibiotic resistance.

Patrick: A serious concern about glyphosate is that it is the active ingredient in the commonly used herbicide ‘Roundup’, developed by Monsanto. If you were to spray glyphosate on green plants they would get sick but wouldn’t actually die, but when glyphosate is mixed with adjuvants (the chemicals that make it more sticky and systemic when sprayed on crops) it becomes more than 100 times more toxic than the active ingredient alone. However, all the tests for agricultural pesticides being conducted by US and EU agencies are only based on the active ingredient, so this has never been tested. This is a serious flaw in the pesticide testing procedures, and is a particular concern in the case of Roundup given its widespread use.

How has glyphosate influenced farming?

Patrick: Farmers have become very dependent on using glyphosate as it’s such an effective weed control herbicide. By preventing major weed build-ups it has enabled farmers to grow long runs of crops in quick succession, perpetuating and enhancing farmers’ ability to grow monocultures.

Richard: It has also been one of the biggest influences on increased farm size and has allowed farmers to abandon ploughing in favour of very tight crop rotations of mainly wheat and oilseed rape.

Guy Smith of the NFU is quoted in Farmer’s Weekly as saying a ban on glyphosate would cost the UK economy 630 million euros annually. He also dismisses concerns about glyphosate levels in urine, arguing they are so low that we shouldn’t be worried. What do you think about this?

Richard: In real terms that’s a relatively small cost of around £5 per person in the UK, and it will pay for itself in terms of the reduction in costs to the NHS. We also need to put that figure in context. A Europe-wide study this year found that the hidden cost to society of endocrine disrupting chemicals (many of which are pesticides) is between €157 and €270 billion a year – 300 times more than the suggested cost of a glyphosate ban in the UK. There are also other huge costs associated with  intensive agriculture, dependent as it has become on the use of glyphosate. For example, the overuse of nitrogen fertiliser is costing European consumers up to €230 billion every year in health and environmental impacts. This makes the cost of a ban seem relatively small.

Patrick: On the point about glyphosate in urine, studies have revealed contamination levels in urine of between less than 1 parts per billion (ppb) and 233 ppb. Indeed 1 ppb does sound very low, but recent evidence from experts has found that endocrine disruption windows are triggered by extremely low concentrations. Therefore, if contamination levels go up to 233 ppb, there is extreme cause for concern.

Richard: There has also been research on laboratory rats given Roundup in drinking water at very low doses which resulted in a large increase in mammary tumours as well as liver and kidney damage. This research needs to be checked by having other scientists repeat the experiment in case the results were not representative, but until this happens our view is that it has to be taken seriously.

How would a ban impact farmers?

Patrick: It would have a significant impact on the high proportion of continuous arable farmers in the UK who’ve been encouraged over the years to develop systems based around this single herbicide.  As a farmer, I know from first hand experience that continuous arable cropping results in a build-up of weeds. Without the use of glyphosate these would have to be counterbalanced through rotations and crop diversity.

Richard: As there are a wide range of other herbicides available, I don’t think a ban would lead to uncontrollable weed problems. But it would need a significant re-design of our farming systems to incorporate other crops such as grass and clover into a long-term rotation.

Patrick: If Roundup is banned, surely it’s only a matter of time before the focus switches to the other toxic pesticides currently available? This could be the beginning of the end of herbicide use in agriculture as we know it, leading to a new chapter of innovation and diversity.

Does glyphosate have other negative impacts on the environment?

Richard: There is a lot of research suggesting that glyphosate is what’s called a ‘chelator’- locking up minerals in the soil and therefore reducing the mineral content in crops that we consume. However, more definitive research is needed before any firm conclusions can be drawn on this.

Patrick: I read some interesting research by Professor Bob Kremer from the University of Missouri, who has discovered that Roundup has a depressing effect on the soil microbiome. He found that Roundup had a half-life (the time it takes to decompose) of over a year, which goes against the previous assumption that it degrades very rapidly in soil.

Do you think there will be a ban on glyphosate?

Richard: I suspect that the pressure on the European Commission will be such that they will seek some sort of a compromise and extend its license for the time being while they review the evidence themselves. However, we must continue to be vigilant, support further research and make sure we are all aware of the risks. Consumers must let politicians and policy makers know how they feel about whether this chemical should continue being used.

Patrick: In their heart of hearts I think the regulators already know that this herbicide is a threat to environmental and public health, but for reasons involving politics and vested interest, they will be extremely reluctant to act. However, the very fact that they haven’t thrown the proposal for a ban out straight away indicates that it’s only a matter of time before something must change.

Photograph: Mike Mozart

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