Over the past two decades, tens of thousands of people living in rural Sri Lanka have been affected by a renal insufficiency, known as CKDu, due to causes that seemed unclear. At the same time, cases of strange kidney diseases have emerged in tropical farming communities around the world.
A field study of wells that supply drinking water to Sri Lankan communities, conducted by researchers at Duke University, has identified a Possible culprit: glyphosatethe active compound in Roundupwhich is the most used herbicide in the world and also in Spain.
The results of the study were published in Environmental Science and Technology Letters last September.
Roundup is a glyphosate-based herbicide that used to control weeds and other pests. Because it is supposed to break down in the environment within a few days or weeks, its use is relatively unregulated by most public health agencies.
However, when glyphosate encounters certain metal ions that harden water, such as magnesium and calcium, glyphosate metal ion complexes can form. AND These compounds can persist up to seven years in water and 22 years in soil.according to the researchers.
“This chemical was always thought to break down very quickly in the environment, but it appears to linger much longer than we expected when it forms compounds in hard water,” said Nishad Jayasundara, Juli Plant Grainger Assistant Professor of Global Environment at Duke University. “We have to consider how glyphosate interacts with these other elements and what happens to this product. when we ingest it into the body as a complex.”
Up to 10% of children are affected
In certain agricultural areas of Sri Lanka, the high and dry climate, combined with its geological conditions, creates the perfect conditions for hard water. It is also in these regions that CKDu kidney failure has reached epidemic levels: up to 10% of children aged 5 to 11 years present signs of early-onset kidney damage.
Jayasundara, originally from Sri Lanka, believed that glyphosate could play a key role in the incidence of this disease due to the hardness of the region’s water, despite the fact that Sri Lanka has banned the use of said herbicide.
To test his hypothesis, Jayasundara teamed up with two other chemists: Lee Ferguson and Jake Ulrich. In collaboration with Mangala De Silva, a professor at the University of Ruhuna, Sri Lanka, the Duke team sampled more than 200 wells in four regions of Sri Lanka.
Ferguson’s lab at Duke uses high-resolution tandem mass spectrometry to identify contaminants, even the slightest trace of them, through their molecular weights. It is a highly sensitive identification and quantification method that allows exhaustive detection of contaminants present in a water system.
Levels up to 44% higher
Through this technique, The researchers found significantly higher levels of the herbicide in 44% of the wells within the affected areas compared to only 8% of those outside those areas.
“In this case we focused on drinking water, but there may be other important routes of exposure [al glifosato]: he direct contact from farm workers who spray the pesticide, or perhaps through food or dust“Explained Ferguson. “I would like to see more studies more focused on these exposure pathways. It seems like there are still things we’re missing,” he added.
Ulrich also found elevated levels of fluoride and vanadium (both linked to kidney damage) in the drinking water of most communities with high CKDu incidence. Researchers agree that More attention should be paid to the impact of each of these contaminants, either individually or together with others.
Scientists believe these results should serve as a serious warning about the risk posed by glyphosate exposure.
Part of Ferguson’s concern is that The characteristics of glyphosate resemble those of another pollutant that has been studied closer to home: the so-called perfluorinated substances or PFASwhich are also known as “forever chemicals” due to their high persistence in the environment.
“We believe PFAS are a drinking water contaminant because they are mobile and persistent. We are now realizing that glyphosate can also be quite persistent in hard water areas,” Ferguson said.
Reference study: DOI: 10.1021/acs.estlett.3c00504
Related news
…………….
Contact of the Environment section: [email protected]