Over the past two decades, a slowly progressing, asymptomatic, and degenerative renal disorder has plagued agricultural workers across the globe. From rice paddy fields in Sri Lanka to sugarcane fields in Nicaragua, the death toll from the mysterious illness known as “chronic kidney disease of unknown etiology” — or CKDu — has reached the tens of thousands.
Studies from the World Health Organization and other authorities have determined that factors associated with CKDu include sustained exposure to arsenic, cadmium, and pesticides. But how do these particular elements connect countries as far apart as Sri Lanka and Nicaragua? Researchers surmised that exposure to the disease had to do with the environmental and occupational setting.
Now a new report published by the International Journal of Environmental Research and Public Health suggests that the epidemic might be connected to the world’s bestselling chemical herbicide: glyphosate.
Marketed worldwide by the chemical company Monsanto under the brand name “Roundup,” glyphosate is a commonly used weed killer. The new report indicates that the compound can become highly toxic to one’s kidneys when mixed with “hard water,” which contains a high concentration of minerals like calcium, magnesium, and iron.
The report hypothesized that glyphosate plays a potentiating role in the relationship of arsenic, cadmium, and pesticide exposure with hard water consumption — a combination exacerbated by low water intake and high temperatures. Agricultural workers afflicted with CKDu have generally been exposed to all of the above.
When asked for comment about the report's implication about their product, Monsanto offered VICE News the following statement:
“Monsanto takes the safety of our products seriously. There are no epidemiologic studies suggesting that exposures to glyphosate-based products are associated with renal disorders either in Sri Lanka or elsewhere. Glyphosate does not cause renal injury in long term animal studies. We are aware of the Jayasumana paper. The authors themselves state that they ‘have hypothesized’ this relationship which has ‘not been given any serious consideration by investigators for the last four decades.’ While speculative theories have a place in science, they need to be investigated and proven to be of practical use. No new data are provided to support this theory, and there are many alternative hypotheses— previous studies have associated employment as a farmer, use of pesticides, dehydration, cadmium exposure, and other factors with the occurrence of renal dysfunction.”
Regarding the lack of serious investigation into the effect of glyphosate noted by Monsanto, the authors concluded in their report that “huge advertising campaigns by glyphosate as the best ever herbicide discovered by mankind” might have contributed to this delay.
This isn’t the first time questions have been raised about glyphosate. A report published last year in the scientific journal Entropy suggested a link between the herbicide and a broad range of health problems, from Parkinson’s disease to infertility. Traces of glyphosate are even found in food. Last year, the EPA raised the levels of glyphosate residue permitted in some fruits and vegetables.