Glyphosate is receiving a lot of undeserved bad press lately, and it is highly misleading. We use many chemicals in our daily lives, and they are safe most of the time because they are used below levels that are harmful. Claims that glyphosate (the main ingredient in Monsanto’s Roundup herbicide) is unsafe are not supported by valid scientific studies.
The recent CT Viewpoints article, “Use Glyphosate with Caution,” by Nancy Alderman was commendable, and its advice to use products as directed is certainly a welcome reminder. However, it perpetuates many misconceptions and fears. Glyphosate is among the safest herbicides in use today. It inhibits an enzyme in plants (but not animals), it decomposes rapidly in soil, and if consumed it largely passes through the body.
Every chemical is toxic at high enough concentration. Caffeine, an organic chemical that many of us are exposed to every day, has a toxicity 10 times that of glyphosate. Because of the extreme sensitively of modern analytical chemistry, traces of glyphosate can be found in foods, but those amounts are hundreds of times below harmful levels (just like many other chemicals we are exposed to daily).
Claims have been raised that glyphosate causes non-Hodgkin’s lymphoma, and Monsanto and its new German owner, Bayer AG, face thousands of lawsuits by people blaming Monsanto’s glyphosate-based herbicides for their diseases. In 2015, the International Agency for Research on Cancer (IARC) added glyphosate to its list of chemicals “probably carcinogenic to humans.” This analysis is flawed and plagued by conflict of interest. Its conclusion has not been supported by studies that adhere to scientific standards.
For starters, the IARC lists coffee and red meat as “probably carcinogenic to humans.” It is also important to understand that, instead of “risk analysis” used by many scientific studies, the IARC uses “hazard analysis,” which sets a much lower standard and has resulted in conclusions based on questionable interpretation of data.
This explains why no regulatory agency around the world (15 in all) considers glyphosate to cause cancer. This includes the World Health Organization, which oversees the IARC and which does not support the IARC’s hazard analysis conclusions. In one of the most recent reviews, Health Canada stated: “No pesticide regulatory authority in the world currently considers glyphosate to be a cancer risk to humans at the levels at which humans are currently exposed.”
Here is a graphic summarizing the assessment of glyphosate safety from 15 regulatory agencies from around the globe, citing epidemiological data and evidence from animal studies, and saying products containing glyphosate are safe if used according to the label instructions.
Many articles on glyphosate select studies that are not supported by the scientific consensus. There have been thousands of studies on glyphosate. I could cite 20 studies that show it was associated with a reduction in cancer. This includes one from the prestigious journal, Nature, which purports that glyphosate may cure malaria. Are any of these significant? Very likely not! Just because something is published does not make it true. It’s not uncommon for published work to be inaccurate. The tadpole and the NHL studies cited by Alderman have their shortcomings and are not representative of the scientific consensus on glyphosate safety.
One way to put this in perspective is to contrast glyphosate to alcohol. Alcohol is a known carcinogen (even the IARC and the scientific community agree on this). It causes head/neck, esophageal, liver, breast and colon cancer. Yet there is no movement to ban alcohol and probably rightly so, as the risk is relatively low. A double standard is being applied to glyphosate.
We hear a lot about “fake news,” and we also generally agree to value science and technology. However, time and time again we see sensational, unscientific and inaccurate information spread in the news media, social media and our conversations. This gets in the way of solving real problems. Pick your topic – climate change, vaccines, it goes on – for various reasons, some probably innocent but often for monetary gain, information is selectively chosen to support an agenda. The current glyphosate scare is a case in point.
Glyphosate’s risks have been vastly exaggerated. Not only is it one of the safest herbicides, it has contributed to more environmentally friendly agriculture and helps combat climate change. The unfounded backlash against glyphosate will do us harm, not good.
Fred Behringer holds a Ph.D. in plant physiology and owns Surveillant LLC, an analytical chemistry laboratory in Old Lyme.