A recent report from the International Agency for Research on Cancer, (IARC), an arm of the World Health Organization, has sent a veritable shockwave through the
agricultural community, and has consumers again questioning possible food safety.
The IARC report classifi ed glyphosate, the active ingredient in the herbicide Roundup, as a “probable” cause of cancer.
What makes that so concerning is that it is widely held that glyphosate is the most heavily used herbicide in the world today.
Glyphosate is so widely used because it has several application options on the farm.
To begin with, the herbicide has been a key tool in chemfallow, which has been a major component of zero-till farming operations. Zero-till has been a key to reducing the loss of valuable topsoil through wind and water erosion.
The herbicide also plays a role in some pre-harvest applications to expedite getting a crop in the bin.
And finally, glyphosate is often used in conjunction with crops like corn and soybeans that the original parent company Monsanto has genetically modified to resist it. This allows farmers to kill weeds but not their crops.
So anything that suggests the chemical is dangerous is worrisome from the farm perspective as farm chemicals such as DDT have been banned in the past. If the IARC report was the fi rst step to that eventuality it would fundamentally change the way farmers farm today.
That said tie the word cancer to anything today and consumers are going to get antsy, and rightfully so. Cancer remains a disease which takes on many forms and while science has helped with earlier detection, and better treatments, far too many still die.
The question comes down to how serious a threat glyphosate is in terms of being a possible cause of cancer. More study is required before shutting the door to glyphosate In a piece by Michael Specter at www.newyorker.com the risk would seem undefi ned. In the story he wrote: “To understand what this report actually means, we need to look at its context. As the University of Michigan’s Andrew Maynard puts it in this excellent explanatory video, the I.A.R.C. classification “doesn’t indicate how likely” glyphosate is to cause cancer. “It is the equivalent of saying a rock could kill you but not pointing out that it probably needs to be dropped on your head from a great height first.”
In a recent AgAdvance magazine article Dr. John McLaughlin, Chief Science Officer of Public Health Ontario, one of Canada’s top epidemiologists and a leader of the largest cross-Canada study on pesticides and health, was sought out for his views on the report.
“Risk and hazard assessments go hand-in-hand,” says McLaughlin. “The purpose of hazard assessment is to know that something has the potential to cause cancer,” he says.
“This is important to know. The hazard assessment done by IARC is complementary to risk assessment done by national regulatory agencies, with one difference being that risk assessment
identifies levels and practices that can be safely used, with most evidence being based on short term studies, whereas cancer can usually take many years to arise so any hazard that might be detected would be based on exposures up to 20 years ago.” Ultimately, he says the value is the ability to use the information to balance the risks and benefits of a certain product, whether that’s glyphosate or sunlight or a chemotheraphy drug that is also classifi ed as Group 2A because it can stymie certain cancer cells in the short term, while increasing the longer-term development of others,” detailed the story.
“None of that suggests we should ignore this study,” wrote Specter. “Yet we also have to be aware of blindly invoking the ‘precautionary principle,’ as many activists argue that we should. In theory, the principle is hard to condemn: it essentially says that we ought not to develop and use a technology unless it is considered safe. Safety is a slippery concept, though. Many people ski voluntarily—an activity with its own dangers. Although hundreds of people drown in their in their own bathtubs, we still take baths. A strict interpretation of the precautionary principle would require us to stop driving because thousands of Americans die each year on the highways. More than that, the principle would have prevented the development of antibiotics, vaccines, X-rays,
elevators, airplanes, and many other signature elements of modern life.”
And therein lies the core problem with the IARC report. While far from a scientist I suspect most chemicals with sufficient exposure have the potential to cause cancer, glyphosate
among them. Still four decades of study has not shown direct correlations, and that hasn’t changed with the IARC report. What it does suggest is diligence is still required in terms of the long term effects of the herbicide, and frankly probably thousands of other substances we use from hair spray, to hand sanitizer to mouthwash.
But the report is not something to panic over, nor should we overreact with calls for banning gylphosate. Instead we need caution in its use, and more study into what long term use might lead too.
