‘Disturbing’: weedkiller ingredient tied to cancer found in 80% of US urine samples

More than 80% of urine samples drawn from children and adults in a US health study contained a weedkilling chemical linked to cancer, a finding scientists have called “disturbing” and “concerning”.

The report by a unit of the Centers for Disease Control and Prevention (CDC) found that out of 2,310 urine samples, taken from a group of Americans intended to be representative of the US population, 1,885 were laced with detectable traces of glyphosate. This is the active ingredient in herbicides sold around the world, including the widely used Roundup brand. Almost a third of the participants were children ranging from six to 18.

Academics and private researchers have been noting high levels of the herbicide glyphosate in analyses of human urine samples for years. But the CDC has only recently started examining the extent of human exposure to glyphosate in the US, and its work comes at a time of mounting concerns and controversy over how pesticides in food and water impact human and environmental health.

“I expect that the realization that most of us have glyphosate in our urine will be disturbing to many people,” said Lianne Sheppard, professor at the University of Washington’s department of environmental and occupational health sciences. Thanks to the new research, “we know that a large fraction of the population has it in urine. Many people will be thinking about whether that includes them.”

Sheppard co-authored a 2019 analysis that found glyphosate exposure increases the risk of non-Hodgkin lymphoma, and also co-authored a 2019 scientific paper that reviewed 19 studies documenting glyphosate in human urine.

Both the amount and prevalence of glyphosate found in human urine has been rising steadily since the 1990s when Monsanto Co. introduced genetically engineered crops designed to be sprayed directly with Roundup, according to research published in 2017 by University of California San Diego School of Medicine researchers.

Paul Mills, the lead researcher of that study, said at the time there was “an urgent need” for a thorough examination of the impact on human health from glyphosate in foods people commonly consume.