Glyphosate is the most widely used herbicide in the world and the main active ingredient in Roundup, a product manufactured by Monsanto. There is much evidence to suggest exposure to glyphosate can have significant adverse effects on human health, despite Monsanto’s continuing assurance that the product is safe.
Glyphosate (N-[phosphonomethyl]glycine), a phosphonoglycine, is sold in a concentrated formulation which is then diluted with water. It’s sprayed on crops to control weeds (Campbell 2014, p.9; Kwiatkowska et al. 2013, p.717). Glyphosate was originally created as a descaling agent to clean hot water systems. It was then later marketed as Roundup in the 1970’s as an agricultural chemical (Campbell 2014, p.9). In 2007, it’s annual global use exceeded 907,000 tonnes (Koller et al. 2012, p.805). After spraying, the product spreads through plants from the leaves to the roots. Crops will uptake any glyphosate present in the soil (Campbell 2014, p.9).
Most farmers and their families are directly exposed to the product, either by mixing, loading or applying it onto crops (Seak et al. 2011, p.892). We also must consider gardeners and groundskeepers who use glyphosate to keep weeds under control and the wider population who visit parks and areas which have been sprayed.
Residues of glyphosate are found in many foods in the diet and there is some evidence that glyphosate can be found in low concentrations within human blood (Kwiatkowska et al. 2013, p.717; Richard et al. 2005, p.716). Toxicity occurs in cellular systems within the human body, disrupting the biosynthesis on aromatic amino acids by gut bacteria and also reducing the transport of serum sulfate (Campbell 2014, p.9).
Roundup and Glyphosate have been the subject of many studies since it was first marketed. The product has been regarded as safe due to the long term studies performed on rodents (Koller et al. 2012, p.806). However, studies conducted within the last decade have determined that occupational exposures to this product can have increased cancer risks (Koller et al. 2012, p.805).
Koller et al. (2012, p.805) studied the effects of exposure to glyphosate by workers spraying the product. They saw evidence of membrane damage and impairment of mitochondrial function when exposed to concentrations of less than 40mg after 20 minutes. Inhalation was found to cause DNA damage in these individuals even after a relatively short exposure time and quantity used, thus creating cytotoxic and genotoxic effects (Koller et al. 2012, p.805). The author has witnessed groundskeepers at local parks around Perth actively spraying the product. This puts the community at risk of toxic exposure as we do not know how much has been sprayed or for what duration.
Richard et al. (2005, p.716) concluded that glyphosate and Roundup is toxic to human placental JEG3 cells within 18 hours of exposure, in lower concentrations than those found in agriculture. The degree of damage increased with exposure time and the concentration used. Such studies explain why many agricultural workers are unable to fall pregnant (Richard et al. 2005 p.717).
Testing Roundup at non-toxic concentrations (in concentrations 100 times lower than the recommended use in agriculture) can affect aromatase, the necessary enzyme needed for oestrogen synthesis (Richard et al. 2005 p.717). Glyphosate disrupts aromatase and mRNA levels. Roundup, not just glyphosate has endocrine and toxic effects (Richard et al. 2005, p.717).
Glyphosate is found in most foods of the normal western diet. Such residues can inhibit the workings of cytochrome P450 and it’s ability to detoxify xenobiotics (Samsel & Seneff 2013, p.1416). This negatively impacts the body over time, manifesting slowly, as inflammation damages cellular systems throughout the body (Samsel & Seneff 2013, p.1416). Consequences of minimal exposure through food can include gastrointestinal disorders, obesity, diabetes, heart disease, depression, autism, infertility, cancer and Alzheimer’ s disease (Samsel & Seneff 2013, p.1416).
If ingested in larger quantities, it is toxic due to the uncoupling of mitochondrial oxidative phosphylation and it can cause myocardial issues, depression and hypotension (Murray et al. 2011, p.236).
Ecologically, glyphosate stays in the soil, leaches into groundwater, rivers and can affect marine populations, thus further exposing the community (Richard et al. 2005, p.716).
Interestingly, GM technology is also a product of Monsanto. Monsanto have made their GM crops resistant to Roundup, so the farmer can successfully spray large quantities of glyphosate on his crops without destroying them. GM crops are thus more likely to have higher levels of glyphosate present in their produce, increasing toxic exposure for both the consumer and the agricultural worker (Campbell 2014, p.9).
I have carefully assessed all evidence used for this post; as many journal articles proposing health benefits of glyphosate had considerable conflicts of interest, with the authors being employed by or previously employed by Monsanto. The toxic effects of glyphosate is worrying especially when we acknowledge that most of the food we eat has been exposed to it. More investigation is needed to determine what the safe residue levels are, if any exist.
Campbell, A 2014, ‘Glyphosate: Its effects on humans’, Alternative Therapies, vol. 20, no. 3, pp. 9-10, viewed 13 March 2015, www.ebscohost.com.
Hokanson, R, Fudge, R, Chowdhary, R, Busbee, D 2007, ‘Alteration of estrogen-regulated gene expression in human cells induced by the agricultural and horticultural herbicide glyphosate’, Human and Experimental Toxicology, vol. 26, pp. 747-752, viewed 13 March 2015, www.ebscohost.com.
Koller, V, Furhacker, M, Nerseesyan, A, Misik, M, Eisenbauer, M, Snasmueller, S 2012, ‘Cytotoxic and DNA-damaging properties of glyphosate and Roundup in human-derived buccal epithelial cells’, Arch Toxicol, vol. 85, pp. 805-813, viewed 13 March 2015, www.ebscohost.com.
Kwiatkowska, M, Jarosiewicz, P, Bukowska, B 2013, ‘Glyphosate and its formulations – Toxicity, occupational and environmental exposure’ Medycyna Pracy, vol. 64, no. 4, pp. 717-729, viewed 13 March 2015, www.ebscohost.com.
Murray, L, Daly, F, Little, M, Cadogan, M 2011, Toxicology Handboook, 2edn, Elsevier, Australia.
Richard, S, Moslemi, S, Sipahutar, H, Benachour, N, Seralini, G 2005, Differential effects of glyphosate and Roundup on human placental cells and aromatase, Environmental Health Perspectives, vol. 113, no. 6, pp. 716-720, viewed 13 March 2015, www.ebscohost.com.
Samse, A, Seneff, S 2013, ‘Glyphosate’s suppression of the cytochrome P450 Enzymes and Amino Acid Biosynthesis by gut microbiome: pathways to modern diseases’, Entropy, vol. 15, pp. 1416-1463, viewed 13 March 2015, www.ebscohost.com.
Seok, S, Park, J, Hong, J, Gil, H, Yang, J, Lee, E, Song, H, Hong, S 2011, Surfactant volume is an essential element in human toxicity in acute phyphosate herbicide intoxication, Clinical Toxicology, vol. 49, pp. 892-899, viewed 13 March 2015, www.ebscohost.com.