Farmers need more than facts to defend glyphosate use

The recent decision by a United Nations agency to dub glyphosate as “probably carcinogenic to humans” sets farming and the food supply chain on a dangerous path, but not for the reasons most might think.

The fact that the data shows, on paper, that the pesticide is probably carcinogenic should surprise nobody.

The fact it was judged based on laboratory testing criteria, without providing the context of its risk when used properly in the real world, should serve as a warning to farmers that they must not let this decision stand without amendments.

Of course, the chemical is not any more dangerous than it was the week before the World Health Organization’s International Agency for Research on Cancer issued its report, but the ground under the debate has become unstable.

Decades of studies have demonstrated glyphosate to be one of the safest pesticides ever produced, in terms of toxicity to humans and animals, and have a relatively short persistence in the environment, but none of that will matter. Such debates seldom come down to discussions about science and real world data. What matters is emotion: which side of the debate manages to win the hearts of the public.

The IARC review placed glyphosate in Category 2A: probably carcinogenic to humans. Glyphosate had previously been classed as Category 2B, which means “possibly carcinogenic to humans.”

The decision comes after decades of studies by independent companies, the U.S. Environmental Protection Agency and Canada’s Pest Management Regulatory Agency that have shown glyphosate to be safe if used in the appropriate manner with the appropriate safety precautions.

The clinical, hazard-based approach used in IARC’s review is a legitimate scientific method, but without context it confuses rather than clarifies.

It’s vital to detail the plausible risk, or how the chemical interacts when used as prescribed with those who handle it and live around it. Yet whether the practical science will matter in the wake of the WHO classification is now in serious question.

The emotional arguments around a substance being classified as a probable human carcinogen may be too much to counter.

Glyphosate is probably the most commonly used pesticide in the world. It is used as general weed killer and is the key herbicide used in every Roundup Ready canola, corn and soybean system. It is also used for crop dry-down and in post-harvest or preseeding no-till systems.

Because it is so ubiquitous on conventional farms, it has become an easy target for activists who see its use as unsustainable and its overuse as a main cause of so-called super weeds, which are difficult to control.

To see what happens when these arguments dominate the agenda, we have only to look at the recent example of neonicotiniods and Ontario’s decision to gradually reduce and ban those seed treatments, even though the science is far from clear.

There may be a case for reduced glyphosate use, and education programs to promote more judicious use could be helpful.

However, the landscape of farming would have to change dramatically if farmers were to lose glyphosate completely. Zero-till and its soil preservation and carbon sequestration benefits would be cast into doubt. And what would farming without glyphosate mean to the prices and availability of the food we love?

Maybe those are the emotional discussions we need to have.

About the author

explore

Stories from our other publications