Be Careful What You Wish For
Farmers get a lot of solicitation junk mail. A few days ago I got a postcard from an ambulance chasing law firm asking me to sign up for a lawsuit concerning glyphosate exposure. I tossed it in the trash straight away, but I was still thinking about it the next day, so I thought I'd share my thoughts as a farmer about glyphosate (Roundup).
The Roundup/glyphosate saga playing out the past few years isn't about public safety, it's about money. The law firm that sent that flyer to me doesn't care about me, they care about the 40% of potential settlement awards they take as commission. To date, glyphosate lawsuits have generated over 11 billion dollars.
Is glyphosate dangerous? Of course, to some degree it is dangerous. It's literally a chemical marketed and sold to kill things. However, the real question is how dangerous is it? On the spectrum of chemicals used by farmers to control weeds, the answer is not very.
Glyphosate was discovered in the early 70's by Monsanto (subsequently purchased by Bayer) while trying to create a new water softening agent. By accident, it was observed that the synthesized compound had some herbicidal activity. After some refinement and further testing, glyphosate hit the market in 1974 under the trade name Roundup.
Glyphosate works by inhibiting a process known as the shikimate pathway, which is not found in animals. This contributes to it's relative safety as a herbicide. as the process it uses to kill plants literally cannot happen in people or animals.
What about the chemical components in the herbicide themselves? Are they dangerous? Again, the answer is likely yes, but not very. LD50, or median lethal dose, is a unit of measurement which signifies the lethal dose of a chemical or substance required to kill 50% of a population exposed to it. Glyphosate has an LD50 of 5600mg/kg. in comparison, caffeine has an LD50 of 192mg/kg and your morning vitamin D supplement has an LD50 of 10/mg/kg! Glyphosate is not acutely toxic by any means.
Glyphosate toxicity over time has also been studied extensively. Long term exposure issues are measured by finding the reference dose of a substance. The reference dose equates to the daily exposure allowable without likely negative effect throughout an entire lifetime. Finding the reference dose is quite complex, but it basically represents the maximum dose with no observable effect in an animal study (usually rats or rabbits) divided by a calculated safety factor. The reference dose for glyphosate is 0.1mg/kg/day. To circle back to one of our examples from earlier, the caffeine in your morning coffee has a reference dose of .0025mg/kg/day, making it 40X more toxic than glyphosate!
Aside from acute and chronic toxicity, carcinogenic potential should also be considered when evaluating the safety of glyphosate. The EPA considers glyphosate to be a non-carcinogen to humans. Various other agencies list glyphosate as non-carcinogenic, possibly carcinogenic, and a probable carcinogen. There isn't a consensus, partially because it's hard to prove what caused a specific instance of cancer when humans are exposed to so many different things in their environment during a lifetime.
While it definitely isn't conclusive, there is a chance that glyphosate could contribute to cancer if exposure levels were high enough over a long enough period. However, the vast majority of these lawsuits were brought forward by residential homeowners and gardeners, not by farmers who have used much larger quantities of glyphosate over much longer periods of time. The scientific proof of these claims is marginal at best.
Bayer has billions of dollars and lawyers galore. They don't need my help defending glyphosate. I'm more interested in the impact on farmers than the impact on Bayer. Glyphosate is a tool for farmers. It isn't without risk, but it's risk should be compared to alternatives. The two attached graphs illustrate the usage of two alternative chemicals. Both have plummeted in recent years, primarily due to the emergence of glyphosate and other chemicals.
Metolachlor was in widespread use prior to glyphosate. Unlike glyphosate, it does have impact on animals at a cellular level. Metolachlor induces cytotoxic and genotoxic effects in human lymphocytes. Metolachlor also affects cell growth in animals. Chicken embryos exposed to metolachlor showed a significant decrease in average body mass compared to the control group in a 2003 study.
Similarly, Cyanazine was used extensively in years prior to the adoption of glyphosate. Cyanazine is a teratogen. (causes birth defects) The herbicide was banned in 2002 primarily for this reason. However, having a safer alternative already in widespread use most certainly expedited this decision. The graph clearly shows usage dropping dramitically just before 2002. Farmers are aware that herbicides have risks to themselves and the environment and want to choose the safest available effective product
Bayer will end the sale of glyphosate to residential consumers in 2023. The herbicide will be pulled from store shelves, but will still be available to agricultural users. This is absolutely an attempt to shield themselves from future litigation, which has primarily come from occasional residential users.
You may be surprised to know that there are several other herbicides that are designed to be sprayed directly on growing crops such as glufosinate, dicamba and 2-4,D. Roundup is not alone in that regard, but none of these are facing the legal and public relation battles that glyphosate is. In fact, most consumers are completely unaware they even exist. The primary reason for that is money. There simply aren't enough users to motivate the lawyers to pursue litigation against those products. But, you can be sure that if one of these products replaces glyphosate on the shelves in hardware stores, the lawsuits and solicitation mailers will soon follow.
It is troubling to me that glyphosate has become such a hot button issue without taking any time to consider the ramifications of a ban on the herbicide. Weed control with herbicides isn't going anywhere any time soon in agriculture. Farmers are going to spray something on their cash crops to control weeds. If you're rooting for the demise of Roundup, be careful what you wish for.
In the interest of full disclosure, I don't actually use glyphosate on my corn. I plant conventional corn that is not genetically engineered to be tolerant of the herbicide. I do use glyphosate around the farm on driveways, fencerows and other areas. Still, it's an important tool for the agriculture industry that I felt was worth spending some time talking about.
Do you have any topics you'd like to see in a future blog? Send me a message!