John E. Franz. The man, the organic chemist, and the name behind the game changing glyphosate discovery. He and his team of chemists at Monsanto sifted through metabolites and compounds eventually coming across glyphosate, better known as RoundUp. At its core, the chemical targets the 5-enolpyruvylshikimate-3-phosphate synthase plant enzyme, or better known as ESPS synthase. This enzyme is involved in the synthesis of key amino acids (which are plant-specific), so disrupting it and therefore killing the plant means the plant needs to be both healthy and actively growing, with around two weeks before plant death. This pathway is absent in humans.
As the patent expired in 2000, there are now 499 other registered products containing glyphosate in Australia and two GM resistant crops (canola, cotton). So why all the fuss? And what about those billion dollar lawsuits?
Well in 2015 the International Agency for Research on Cancer (IARC) found glyphosate as a “probable carcinogen”. Yet IARC also rate frying food, eating red meat and consuming hot beverages at the same 2A “probably carcinogenic” level. Even coffee and other heated/cooked foods containing acrylamide are rated on this same level. And on the occupation side of things, shift work, hairdressing and manufacturing all fall into the same category.
Yet, there is significant research detailing the inconclusive nature and impact of glyphosate on cancer risk. In smoking and other known highly carcinogenic compounds which are regularly consumed, there is a clear link between smoker number, location and various forms of cancer. In glyphosate the link appears to be absent.
Other epidemiological studies have found similar lack of association between exposure and cancer incidence. In 54,251 applicators over a period from 1993 to 2012, “no association was apparent between glyphosate and any solid tumors or lymphoid malignancies overall, including NHL and its subtypes”.
Nevertheless, in defending the chemical, given its importance to food production, it is still important to continue to scrutinise and assess the corporate management of and influence in science. This is critically important, such that results like those presented above can be trusted and the philosophy underpinning science can be maintained.
At the same time, safety requires that labels are followed and correct PPE is worn. Suggestions of farmers being drenched in glyphosate imply very poor application methods and potential for carelessness in the application of more toxic chemicals. Moreover, it is interesting that in some of these cases, the impact of glyphosate over long periods of time was able to be teased out from the exposure to other carcinogenic compounds and the compound solely blamed for the presence of cancer.
All in all, continual evaluation of scientific findings and claims is fundamental to scientific progress. This is welcomed in the industry and actively promoted. Glyphosate to date has been cleared by some of the most well recognised regulatory authorities in the world as being safe for use, findings we should have confidence in.
The chemical has been incredibly important in the implementation of conservation agriculture, rapid increases in production efficiency and importantly the sustainable production of food.