Is Glyphosate Exposure on the Up? — Chromatography Investigates

A recent study carried out by the University of California San Diego (UCSD) School of Medicine has found that human exposure to glyphosate has increased significantly since genetically modified crops were introduced. What’s glyphosate? Should we be worried?

Roundup Ready

Glyphosate is a broad-spectrum herbicide that was synthesized in the 1950s by Swiss chemists. It was originally patented as a chelator — a chemical that combines with other chemicals, including calcium and copper, and removes them from solution. Then, while the chemical company Monsanto were looking for water softening chemicals, they found that some of them had herbicidal properties. They developed these and glyphosate was discovered independently and patented as an herbicide in the early 1970s.

It was brought to market in 1974 as ‘Roundup’ — and became one of the best-selling herbicides in the world. It works by stopping the synthesis of key amino acids needed by plants — thus killing them. Glyphosate is easily absorbed through the leaves, but poorly absorbed by the roots — it is thus most effective on growing plants as it is easily transported through the plant.

Glyphosate use rising

It is estimated that the use of glyphosate has increased significantly in the last few decades. Genetically modified crops were introduced in the US in the early 1990s and the increase in glyphosate use has been linked to rise in genetically modified crops that are resistant to glyphosate. But what does that mean for human exposure? Does an increased use in glyphosate mean there is more of the herbicide in our bodies?

Exposure to glyphosate increasing?

Environmental exposure to glyphosate by eating crops sprayed with glyphosate can possibly be detrimental to human health — and the researchers from the UCSD School of Medicine set out to find out if our exposure to glyphosate has increased. In a letter published in the Journal of the American Medical Association, they report on a group of people who originally had their glyphosate and its metabolites analysed in 1993 just before the introduction of genetically modified crops. They were sampled again 23 years later — participants from the Rancho Bernardo Study of Healthy Aging.

The team analysed the blood samples from 100 participants using high performance liquid chromatography — a technique wisely used for plant analysis as discussed in the article, LC-MS/MS and GC-MS/MS Multi Residue Pesticide Analysis in Fruit and Vegetable Extracts on a Single Tandem Quadrupole Mass Spectrometer.

The researchers found that glyphosate, and its metabolite aminomethylphosphonic acid, had increased in concentration by over 500 percent since the introduction of genetically modified crops. In a press release from UCSD, Paul Mills stated: ‘Our exposure to these chemicals has increased significantly over the years but most people are unaware that they are consuming them through their diet.’ With few human studies of glyphosate, the public need to be better informed of the risks — after all, glyphosate is listed as a carcinogen in Europe and in California.