A European Commission decision on whether to relicense – or effectively ban – the use of glyphosate-active ingredient as a herbicide has been delayed until next year following a call from the Netherlands to wait until an independent assessment of the compound’s risks to human health.  The decision is important because glyphosate helps to maintain crop yields being the most widely used herbicide globally – comprising ~ 80 per cent of all herbicides[i], and 2014 seeing nearly a million tonnes applied globally[ii].  This article argues that if a right decision on its use is to be reached, in this instance, the debate should be framed around risks to ecosystems rather than human health.

Why should the decision be based around risks to ecosystems rather than human health ? From the evidence, it seems there needs to be a reconsideration of the reason why glyphosate is an issue in the first place.  The glyphosate debate follows on from a report by the World Health Organisation (WHO) last year stating that the compound was “probably carcinogenic to humans”.  However, basing the debate on the potential risks to human health might be preventing an agreement over what to do: the debate needs to shift instead toward a nuanced discussion around the effect glyphosate has on the environment.

What is the evidence for this ? Firstly, we are surrounded by chemicals considered to be carcinogenic to humans on a daily basis, from car fumes and construction dust to processed meats and even your cup of coffee.  So yes, glyphosate could be carcinogenic to humans if we were repeatedly exposed to it at extreme doses – but is it carcinogenic at the concentrations found in our food ?

Apparently not – and by quite a wide margin.  The FAO released findings of a study on Monday – the largest study of its kind – indicating that glyphosate is “unlikely to pose a carcinogenic risk to humans from exposure through the diet”4; the concentrations just aren’t high enough.  We can see this disparity by looking at the current concentrations of glyphosate found in food and the safe guideline limits (Figure 1).

Glyphosate_plot_and_caption

A recent study found glyphosate concentrations of up to 30 μg (micrograms) per litre in some popular German beers5; causing considerable hoopla with various environmental groups.  However, 30 μg / litre is more than one order of magnitude lower than the lowest reported safe drinking limits of between 700 μg (US EPA)6 and 5000 μg (WHO)7.  Therefore even the highest concentrations of this chemical found in food and drink are considerably lower than the maximum safe limits, making a ban on the basis of human health risks a hard case to make.

On the other hand, there is strong evidence of glyphosate causing complications in ecosystems and biodiversity.  The example cited most frequently is the detrimental effect glyphosate has had on the prevalence of Monarch butterflies in North America8.  However, this is not due to the direct toxicity of glyphosate to the butterflies; it is in fact due to the dependence of the Monarch caterpillar larvae on a particular variety of weed9; which has been eradicated by glyphosate.  Therefore, the Monarch butterflies could be supported by retaining controlled patches or corridors of these weeds within the landscape – suggesting that even aspects of the environmental case need to be deliberated before an outright ban is implemented.

The EC also needs to look at this issue from an economic perspective.  Glyphosate-based herbicides increase crop yields by over 20 per cent10, keeping food prices stable and reducing the need for inputs such as fertiliser and artificial nutrients.  Banning the substance would put pressure on farmers at a time when farm labour for activities such as manual weeding is increasingly unavailable as more and more people move from rural to urban locations11.  If this tool in the farmer’s armoury is taken away, it needs to be adequately replaced with something else which will maintain yields, keep farms viable and keep food supplies secure.

It is clear that this is not a simple case of either allowing the use of glyphosate to continue unabated or to ban its use altogether.  This compound is integral to agricultural systems across the world, serves a critical function on the farm and helps to feed the global population; this is reflected in the fact that EU member states have failed to reach a consensus a second time.  The right consensus should be sought by basing the dialogue around the evident environmental and economic risks rather than the less imminent risks to human health.  The final decision – whenever it is made – needs to include the intent to investigate potential solutions for using glyphosate, solutions which strike a balance between human needs and protection of the environment.

[i] The figure of 80 per cent for the percentage of herbicide use comprising glyphosate has been derived here based on total pesticide usage of 2.54 billion kilograms (from 2009, Michael C. R. Alavanja, ‘Pesticides Use and Exposure Extensive Worldwide’, Reviews on environmental health, 24.), and herbicide comprising 40 per cent of this total.

[ii] The figure of 0.82 billion kg of glyphosate applied globally has been derived here using the global application density of 0.53 kg / ha (from 2016, Charles M. Benbrook, ‘Trends in Glyphosate Herbicide Use in the United States and Globally’, Environmental Sciences Europe, 28.) multiplied by total non-organic arable land of 1.56 billion hectares (from 2012, FAO, ‘Faostat’, ed. by United Nations Food and Agricultural Organisation.

Bibliography

1              2009, Michael C. R. Alavanja, ‘Pesticides Use and Exposure Extensive Worldwide’, Reviews on environmental health, 24, 303-09.

2              2016, Charles M. Benbrook, ‘Trends in Glyphosate Herbicide Use in the United States and Globally’, Environmental Sciences Europe, 28, 1-15.

3              2012,FAO, ‘Faostat’, ed. by United Nations Food and Agricultural Organisation (

4              A. Neslen, ‘Glyphosate Unlikely to Pose Risk to Humans, Un/Who Study Says ‘, The Guardian 2016.

5              C. Copley, ‘German Beer Purity in Question after Environment Group Finds Weed-Killer Traces’, reuters 2016.

6              2007,EPA, ‘Drinking Water Standards and Health Advisories Tables’,  (US Environmental Protection Agency).

7              2008,WHO, ‘Guidelines for Drinking-Water Quality Third Edition Incorporating the First and Second Addenda Volume 1 Recommendations’,  (World Health Organisation).

8              NRDC, ‘Epa Agrees Monarch Butterflies Are in Jeopardy, but Refuses to Use Authority to Limit Habitat-Killing Pesticide’2015) <https://www.nrdc.org/media/2015/150624>.

9              2013,FoE, ‘The Environmental Impacts of Glyphosate’,  (Friends of the Earth Europe).

10           2003,NCFAP, ‘The Value of Herbicides in Us Crop Production’,  (National Centre for Food and Agricultural Policy).

11           2015, M. M. Hossain, ‘Recent  Perspective  of  Herbicide:  Review  of  Demand  and  Adoption  in  World Agriculture ‘, J. Bangladesh Agril. Univ. , 13, 19–30.

 

 

Advertisements