Farms and Food: The Implications of Glyphosate Usage on Human Health

Glyphosate was first available to the International Agriculture Industry in 1974 and has since become the most widely used herbicide and desiccant across the globe. The chemical is best known by its commercial name “Roundup”, originally coined by the Monsanto Company when it became available to the American public as a backyard weed killer [1]. Since its debut in both commercial and residential use, glyphosate has become an integral part of how the agriculture industry is able to feed the mouths of billions. However, in recent years, the versatile herbicide and desiccant has come under fire for its linkage to the development of cancer, chronic disease and genetic disruption in humans [2].

Glyphosate is available in a variety of chemical forms, most commonly in salt form. It is mixed with other “inert ingredients” to make the popular gardening product we know as “Roundup” and many other weed killers. The typical American consumer uses this product in their lawn care regimen to kill weeds and maintain home gardens [3]. However, the large-scale use of this chemical in industrial farming is causing experts to raise concerns about whether or not it should be used. Farmers use glyphosate as a chemical desiccant to accelerate the harvesting process of a crop. The advantage of using dessicants is that they allow for a timely harvest, giving farmers the ability to choose when each crop will be harvested to ensure that none of them spoil.

The timing of spraying a crop with desiccant is where the problem lies. If sprayed too early, the chemical will be taken up by the growing plant and enter the seed. If sprayed too late, the chemical will end up in the grain. This crop harvesting process, commonly known as “green burndown”, has led to alarmingly high residues of glyphosate in our food supply, either through processed foods or consumed by our livestock [4]. At trace levels, this chemical does not pose a threat to the human body. However, its use as a desiccant, in addition to its original use as an herbicide, has been oversaturating farmland, and in turn, our food supply.

In a 2015 study conducted by the Canadian Food Inspection Agency, it was discovered that glyphosate was found in 30% of 3,200 manufactured food items. Other studies have uncovered that glyphosate residues have exceeded maximum residue limits, or MRLs, in commercially produced beer, wine, and Cheerios. MRLs are experimentally determined by feeding animals herbicide until detrimental effects are observed. While knowing these limits is important for protection of consumer health, they are also used as a means of negotiations between countries to lower prices of food or turn a profit. Even though shipments of grain, wheat, barley, etc. may exceed MRLs, countries will still buy or sell the food for lower prices. In 2011, the EU rejected oats from Canada for MRLs that were 40 times the national limit. Additionally, it is estimated that 300 million pounds of glyphosate are used on US farms alone each year.

The problem for humans is that glyphosates disrupt the gut microbiome. Desiccants not only kill plants. They also destroy bacteria in the soil and in our stomachs. They act similarly to antibiotics, decimating both the good and bad bacteria in our gut. When our microbiome is colonized with good digestive bacteria, we have a greater level of immunity. The ingestion of herbicides, however, significantly disturbs our gut bacteria, potentially leading to diseases [5]. A 2020 study published in the Journal of Environmental Pollution noted that “a wide array of human disorders and diseases, such as metabolic alterations, DNA damage, kidney damage, reproduction toxicity, mental conditions like attention deficit hyperactivity disorder (ADHD), Alzheimer’s, Parkinson’s, celiac disease, autism, effect on erythrocytes, leaky gut syndrome, cancers, etc. are also associated with glyphosate-based herbicide formulations” [2]. Exposure to this chemical at high levels increases toxic load on the body past normal levels. The investigation into this herbicide gained even more traction in 2015, when it was classified as a “probable carcinogen” by the World Health Organization [1].

While there is still not enough research to sway the argument to one side or another, it is clear that the use of glyphosate is beginning to have adverse effects. We can reduce risk of exposure to the chemical by washing our produce and buying organic, but the overuse of glyphosate in agriculture must be addressed in order to better our farms, food, and overall health.

References

1. Davoren, M. J., & Schiestl, R. H. (2018). Glyphosate-based herbicides and cancer risk: a post-IARC decision review of potential mechanisms, policy and avenues of research. Carcinogenesis, 39(10), 1207–1215. https://doi.org/10.1093/carcin/bgy105

2. Meftaul, I. M., Venkateswarlu, K., Dharmarajan, R., Annamalai, P., Asaduzzaman, M., Parven, A., & Megharaj, M. (2020). Controversies over human health and ecological impacts of glyphosate: Is it to be banned in modern agriculture?. Environmental pollution (Barking, Essex : 1987), 263(Pt A), 114372. https://doi.org/10.1016/j.envpol.2020.114372

3. Gillezeau, C., van Gerwen, M., Shaffer, R.M. et al. (2019). The evidence of human exposure to glyphosate: a review. Environ Health 18, 2. https://doi.org/10.1186/s12940-018-0435-5

4. Hart, M. (2018, November 21). Herbicide is what's for dinner. Nautilus. Retrieved October 27, 2022, from https://nautil.us/herbicide-is-whats-for-dinner-237256/

5. Rusiecki, J. A., Hou, L., Lee, W. J., Blair, A., Dosemeci, M., Lubin, J. H., Bonner, M., Samanic, C., Hoppin, J. A., Sandler, D. P., & Alavanja, M. C. (2006). Cancer incidence among pesticide applicators exposed to metolachlor in the Agricultural Health Study. International journal of cancer, 118(12), 3118–3123. https://doi.org/10.1002/ijc.21758