By Erik Stokstad
Erik is a reporter at Science, covering environmental issues and UK research.
It's hard to find an herbicide like glyphosate. It’s cheap, highly effective, and is generally regarded as one of the safest and most environmentally benign herbicides ever discovered. But a report last year that glyphosate could cause cancer has thrown its future into jeopardy. Now the European Union faces a 30 June deadline to reapprove its use, or glyphosate will not be allowed for sale. Here's a quick explanation of the issues.
Who uses glyphosate?
Just about everyone who hates weeds. The herbicide is widely sprayed to fight weeds along railroad tracks, in backyards, city streets, parks, and elsewhere. Many kinds of agriculture rely on glyphosate as well—and farmers are by far the biggest users. (Sales skyrocketed in the United States and Latin America after Monsanto and other companies genetically modified soybeans and other crops to withstand the effects of glyphosate. That means farmers can easily kill weeds without harming their crops.) The herbicide has done more than benefit farmers' profits; glyphosate has also curbed soil erosion by facilitating no-till agriculture, the practice of spraying fields before planting instead of plowing up weeds.
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| Without glyphosate, fighting weeds will get more expensive and more complicated. Chafer Machinery/Wikimedia Commons |
Why is it controversial?
Environmental advocates have long worried about health effects of pesticides and herbicides, including glyphosate. The U.K. Soil Association, for example, wants a ban on pre-harvest spraying of wheat fields, a practice that kills green heads of wheat and allows an earlier harvest, but also leaves residues of glyphosate in the grain. Trace amounts have been found in bread and beer, causing anxiety among consumers. If you're a chemical company selling herbicides in Europe, it's very bad news to mess with the perceived purity of food.
What makes glyphosate a big issue in Europe right now?
A bombshell report. Like other regulatory agencies, the European Food Safety Authority (EFSA) reviews the science on pesticides and herbicides every decade or so. If the evidence still suggests that the chemical is safe enough, EFSA allows member nations to decide whether or how they want to make it available. EFSA was in the process of reviewing glyphosate, when the International Agency for Research on Cancer (IARC)—which independently gathers health data for the World Health Organization—declared glyphosate a “probable human carcinogen” in 2015. Nongovernmental organizations began a vigorous campaign to prevent the reregistration of glyphosate. Meanwhile, chemical companies and agricultural trade groups defended its safety record, pointing out that every regulatory agency had given glyphosate a green light.
Wait, why didn't the health reviews of glyphosate come to the same conclusions?
One reason is that they ask different questions. IARC evaluates the hazard of a chemical—in this case, whether it could cause cancer. It does not ask how likely that is to happen, or in how many people. Regulatory agencies like EFSA also evaluate the risk of harm, depending on factors such as the toxicity and the way people are exposed to a chemical. Given the trace amounts of glyphosate that people typically ingest, EPA and other regulators have concluded that glyphosate is not likely to cause cancer or other harm. IARC noted “limited evidence” of a cancer risk to farm workers, but regulators have not been convinced that glyphosate is a danger there either.
Is that the only difference between IARC and the other reviews?
There's also an issue of transparency and trust. IARC only considers peer-reviewed scientific papers and government studies. Regulatory agencies also look at unpublished and confidential studies conducted by and for the herbicide manufacturers. Industry critics are highly skeptical of such data.
It’s not just about cancer, is it?
No. Many Europeans are worried about the environmental impact as well. And glyphosate has come to symbolize industrial agriculture and corporate control of food and farming. Europeans who value locally-owned agriculture and organic farms (which can’t use glyphosate and other synthetic agro-chemicals) are more likely to support a ban, regardless of whether glyphosate causes cancer or not. But the only “easy” legal mechanism to clamp down on glyphosate is because of its alleged human health risk.
What happens next?
So far there's been a deadlock. The decision was in the hands of the Standing Committee on Plants, Animals, Food and Feed (PAFF), which is made up of representatives from the European Union's 28 member states. But PAFF has failed to reach a majority in several past meetings, even as the proposals were scaled back to ever-shorter reapproval periods for glyphosate. On 23 June, an appeals committee will vote. It may decide to renew the approval for a short period, say 1 year, to keep glyphosate available while the debate continues. Without a qualified majority deciding to renew, the approval will expire on 30 June, and the compound will have to be taken off the market in all E.U. countries.
And what would happen then?
Industry’s Glyphosate Task Force warns of dire consequences, such as rising food prices, falling exports, and crop yields dropping by 5% (for oilseed rape) to 40% (for sugar beets). Environmental advocates point to alternative strategies for weed control, including mowing, plowing, and rotating crops. Other herbicides are available, but they're not as effective. Without glyphosate, fighting weeds will get more expensive and more complicated.
Source: Science| Orig. posted:Jun. 17, 2016.
LG Comment: There are a lot of controversies about glyphosate that is an active matter of many total herbicides including notorious RoundUp, linked to RounUp Ready GMO. This article, not necessarily, reflects the position of LG on this issue. However, the article is given as a credible contribution to the subject.
The facts are:
The excessive use of total herbicides is a consequence of long term wrongdoings in primary food production. The "Green revolution" and all the "revolutions" in agriculture led to intensification and industrialization of agricultural production. The yield of major crops has been increased 3 to 5 times, but inputs grew higher, as well. Having that level of production, crop rotation the essence of healthy agriculture has been abandoned largely. Consequently, weeds, diseases and pests became limitation factor in that industrialized agricultural practice. The solution has been found in extensive use of chemicals in plant protection. Soon enough, these chemicals were combined with GMO to enable "free hands" chemical use with no fear of damaging non-targeted cultivars. Results are green-asphalt and super weeds, resistant to herbicides!
Now, let's talk a bit about glyphosate [N-(phosphonomethyl) glycine]. This is wide range herbicide that blocks the effect of an enzyme named 5-enolpyruvylshikimate 3-phosphate synthase which, plays the key role in synthesis of aromatic amino-acids: Phenylalanine, Tyrozine, Tryptophan. A deficiency of these amino-acids leads to the death of affected plants. Talking humans, all three amino-acids play some important role in human organism. Common knowledge is that the half-life of glyphosate in soil ranges between 2 and 197 days; a typical field half-life of 47 days has been suggested. Soil and climate conditions affect glyphosate's persistence in soil. The median half-life of glyphosate in water varies from a few to 91 days. However, after some results that period could be much longer, up to 22 years. Some scholarly articles report that "a field test showed that lettuce, carrots, and barley contained glyphosate residues up to one year after the soil was treated with 4.15 kg of glyphosate per hectare". So, the results are fuzzy. Taking the worst case scenario into consideration, it is not a rocket science, it is easy to comprehend that glyphosate could enter the food chain causing certain damages to non-targeted organisms including humans. The results are ambivalent about the exposure to glyphosate and human diseases. Some scholarly investigations report "... that endocrine and toxic effects of RoundUp, not just glyphosate can be observed in mammals". Time- and dose-dependent effects of Roundup on human embryonic and placental cells has been reported, as well. The work of Nora Benachour and Gilles-Eric Séralini clearly confirms that "the adjuvants in Roundup formulations are not inert. Moreover, the proprietary mixtures available on the market could cause cell damage and even death around residual levels to be expected, especially in food and feed derived from R formulation-treated crops".
The facts are:
The excessive use of total herbicides is a consequence of long term wrongdoings in primary food production. The "Green revolution" and all the "revolutions" in agriculture led to intensification and industrialization of agricultural production. The yield of major crops has been increased 3 to 5 times, but inputs grew higher, as well. Having that level of production, crop rotation the essence of healthy agriculture has been abandoned largely. Consequently, weeds, diseases and pests became limitation factor in that industrialized agricultural practice. The solution has been found in extensive use of chemicals in plant protection. Soon enough, these chemicals were combined with GMO to enable "free hands" chemical use with no fear of damaging non-targeted cultivars. Results are green-asphalt and super weeds, resistant to herbicides!
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