The Health Impacts of Roundup Formulation
Most people are aware of Glyphosate [N-(phosphonomethyl)glycine], the main active ingredient in the formulation Roundup, as it is the most widely used broad-spectrum systemic herbicide in the world (Sritana et al., 2018). Glyphosate is used on food crops such as corn and soybeans, genetically modified to be resistant to the herbicide, with concentrations ranging from 1% to 41%, depending on domestic or agricultural use. Although there has been much debate centered around the use of glyphosate in both scientific and civilian communities alike, one cannot discount the mounting evidence pointing to its toxicity and carcinogenicity reported in both animal and human studies. Even more frightening, is that the majority of available studies asserting its safety have only tested glyphosate in its isolation, whereas the combination of active and inert ingredients of Roundup have been shown to be substantially more harmful (Mesnage et al., 2014). Glyphosate’s toxicity is directly related to its mixture with the numerous other proprietary compounds in the formulation of Roundup, and as such, more tests are underway to determine its health risks (NIEHS, 2018; Sritana et al., 2018).
The Pathogenesis of Glyphosate
Glyphosate works by inhibiting the enzyme, 5-enopyruvylshikimic acid-3-phosphate synthase, present only in plants and some microorganisms (Sritana et al., 2018). However, some researchers have also shown that glyphosate can alter function of a key metabolic enzyme, cytochrome P450 (Richard et al., 2005), which may explain a plausible mechanism by which glyphosate is involved in Celiac disease (Sritana et al., 2018). Rat studies have revealed glyphosate’s toxicity to multiple systems, including the nervous system (Hernández-Plata et al., 2015), and its disruption of steroid hormone synthesis via inhibition of the enzyme aromatase in human placental cells (Richard et al., 2005). Furthermore, in a study that had to be conspicuously retracted, Séralini et al. (2014) found that long-term glyphosate exposure in rats fed minute residues of Roundup formulation resulted in premature death, sex hormone modification, mammary tumor development, and other endocrine disruptive effects; as well as significant liver and kidney damage. Even more recently, Mao et al. (2018) discovered that glyphosate exposure at doses considered safe, had significant microbiome-altering effects in rats, particularly during pre-pubescent development.
Multiple case-control studies exist from Canada, USA, and Sweden, indicating elevated risk for the development of non-Hodgkin lymphoma (NHL) from glyphosate exposure (De Roos et al., 2005; Schinasi & Leon, 2014; Guyton et al., 2015). In an analysis of the Agricultural Health Study (AHS), a prospective cohort study, De Roos et al., 2005 found a significant association between multiple myeloma and increasing glyphosate usage, suggesting a possible dose–response relationship in humans. It is worth mentioning that glyphosate is just one of the many toxic agricultural chemicals (pesticides, herbicides, insecticides) causing threat to human health. In a systematic review and meta-analysis of 25 years’ worth of published epidemiologic data, Schinasi & Leon (2014) revealed a significant association between non-Hodgkin lymphoma (NHL) and occupational exposure to carbamate insecticides, organophosphate insecticides, the herbicide 2-methyl-4-chlorophenoxyacetic acid, and lindane; as well as a clear link between certain chemicals and B-cell lymphomas, a subtype of NHL. The reason this is important is that glyphosate is never used in isolation in farming practices, with the majority of famers being exposed to numerous chemicals on a daily basis, in the Roundup formulation as well as other agricultural products. In a recent study, Sritana et al. (2018) demonstrated that even low doses of glyphosate in the range of human exposure, can significantly modulate estrogenic activity, suggesting a plausible mechanism behind glyphosate’s role in cancer development and progression. By acting on the estrogen signaling pathway, researchers revealed how glyphosate could mediate growth of cancers such as that of the breast and bile ducts (Sritana et al., 2018).
To the disbelieving scientists, corporations and law-makers who question civilian assertions of Roundup’s lack of safety, in the first study of its kind, Mesnage et al. (2014) established that the mixture of adjuvants contained in 8 out of 9 tested pesticide formulations were up to one-thousand times more toxic to human cells than their active ingredients alone! Roundup was one of the worst herbicides and insecticides tested, 125 times more toxic than glyphosate. Thus, studies like this render the acceptable daily intake values of glyphosate and other pesticides useless, since these norms are calculated from the toxicity of solely the active ingredient. This also implies that previous tests measuring toxicities greatly underestimate true environmental exposures encountered by humans (Mesnage et al., 2014).
The Pervasiveness of Glyphosate
Exerting both ecological and human impacts, glyphosate and its major metabolite, aminomethylphosphonic acid (AMPA), are ubiquitous, having been detected in agricultural products; the food chain; human breast milk, serum and urine; as well as soil, water, and air (Kongtip et al., 2017; Steinborn et al., 2016; Conrad et al., 2017; Simonetti et al., 2015; Mercurio et al., 2014). According to an analysis of U.S. and global trends, genetically modified herbicide resistant crops make up 56% of worldwide glyphosate use, and in the U.S., account for more than 90% of the corn and soybeans grown (Benbrook, 2016; Washington, Dept. of Agriculture, 2018). Glyphosate use encompasses other agricultural sectors as well, such as gardening, with over 750 products containing this herbicide. This poses significant challenges due to a global increase in weeds resistant to glyphosate, resulting in farmers having to significantly increase glyphosate application, which further exacerbates health risk concerns. Furthermore, next-generation crops will pose to be an even greater threat due to future genetic modifications to resist even more herbicides, leading to potentially significant ecological and health perturbations (Benbrook, 2016).
In 2015, the International Agency for Research on Cancer (IARC) classified glyphosate as a “probable human carcinogen.” (Guyton et al., 2015; Portier et al., 2016). This conflicted with the European Food Safety Agency’s (EFSA) later assessment, which did not find an association between glyphosate and cancer (Portier et al., 2016). Due to this regulatory uncertainty, in 2017, the European Commission authorized the use of glyphosate for an additional five years. Although seemingly conflicting reports exist regarding the hazards of glyphosate, one must remember to be skeptical of industry-sponsored studies which have vested interests and billions of dollars at stake. Additionally, as previously stated, the toxicity of glyphosate is compounded by its reactivity with other chemicals in the formulation, as well as its bioaccumulation.
I agree with the European Parliament’s decision to oppose the authorization of glyphosate and to base approvals on independent, peer-reviewed research, rather than industry-sponsored studies. It is concerning that since the introduction of Monsanto’s Roundup in 1974, that only now is the government examining the safety of glyphosate-based formulations, containing not just glyphosate but other inert substances. Although it is a step in the right direction that The National Toxicology Program (NTP) is working on conducting this new research, I fear that in the time it will take to conduct these studies, more lives will be irrevocably lost, and our ecosystem, permanently devastated.
Healthier Alternatives and Solutions
Our lives and planet depend on the transparency of our government, political leaders, regulatory agencies, corporations, and research scientists. Law-makers ought to employ the precautionary principle and realize that the combined effects of adjuvants and active ingredients, amplified by their bioaccumulation, represent a substantial threat to human health. Independent research studies need to be promoted, testing alternatives to these dangerous pesticides. I propose not just the banning of one chemical compound alone, but for an ideological shift from our current state of a reactive society, to a proactive, informed society. As citizens, we have the right to question current regulations and all that goes into our food, water, soil, and air. Without this ideological shift, I fear the future of our planet is at great peril.
Thankfully, there is a large movement of aware consumers, green industry professionals, and independent scientists, willing to fight back. Studies show that organic faming methods can be just as effective, but much safer, than glyphosate-based formulations (Costa et al., 2014; Rodale Institute, 2018). In the longest-running trial comparing organic vs. conventional agriculture in North America, the 30-year Farming Systems Trial by the Rodale Institute concluded that the corn and soybean crops grown in their organic systems produced equivalent yields to their conventionally grown counterparts, but also tolerated significantly higher levels of weed competition (Rodale Institute, 2018). Although commercially-available herbicides may not be as long-lasting as a single-application weed-killer like glyphosate, they can serve as effective alternatives when used alongside optimal cultural practices such as maintenance of soil health, proper tillage and seeding, irrigation, cultivar selection, and the application of additional spot treatments. Cinnamon and clove essential oils extracted from plants have also shown to be effective natural herbicides, useful for organic farming systems (USDA 2002). While the use of acetic acid (vinegar) has been shown to have conflicting efficacy, homeowners and farmers can also keep in mind that mechanical methods, such as mulching, flame treatments, hand-picking of weeds, and animal grazing, can serve as additional viable alternatives to chemical methods of control (USDA, 2012; Rodale Institute, 2018).
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