– Data also shows rise in detectable levels of glyphosate metabolite

by Kristen Monaco, Staff Writer, MedPage Today
October 25, 2017

Exposure to glyphosate, an herbicide (and endocrine-disrupting chemical) commonly used in agriculture, has risen during the past few decades in the U.S., according to researchers.

The prevalence rates of adults having detectable levels of glyphosate in their urine has significantly increased during the past 20 years (Wald statistic 80.5, P<0.001), reported Paul J. Mills, PhD, of the University of California San Diego in La Jolla, and colleagues. Specifically, prevalence rates for urinary excretion were as follows:

• 1993-1996: 0.120, 95% CI 0.064-0.200
• 2014-2016: 0.700, 95% CI 0.600-0.788

Detectable levels of aminomethylphosphonic acid (AMPA), a metabolite of glyphosate, have also risen during this time (prevalence rate 0.050, 95% CI 0.016-0.113 vs. 0.710, 95% CI 0.611-0.796; Wald statistic 103, P<0.001), they wrote in a research letter in the Journal of the American Medical Association.

Glyphosate, sold by Monsanto under the name Roundup, is most heavily used in connection with crops genetically modified to resist it; it’s also desiccant for small non-GMO grains. “Environmental exposure through dietary intake of these crops has potential adverse health effects and can be assessed by measuring urinary excretion,” the authors wrote, due to the potential endocrine-disrupting properties of glyphosate and AMPA.

Utilizing the Rancho Bernardo Study of Healthy Aging cohort, the researchers assessed a subgroup of 100 randomly selected individuals living in Southern California (mean age 77.7 at last follow-up). All participants had provided routine urinary samples during five follow-up visits from 1993 to 1996 through 2014 to 2016.

The urine samples were assessed using a high-performance liquid chromatography and mass spectrometry. A total of 70 participants had identified glyphosate levels over the limits of detection (0.03 µg/L), and 71 individuals had detectable AMPA levels (0.04 µg/L).

Among those with detectable levels, mean glyphosate reached 0.449 µg/L by the last follow-up, while mean AMPA levels hit 0.401 µg/L.

“Animal and human studies suggest that chronic exposure to glyphosate-based herbicides can induce adverse health outcomes,” the authors. The called for future research to further investigate the possible associations between adverse health outcomes and glyphosate exposure.

The EU parliament called for glyphosate to be banned by 2022, just ahead of the scheduled EU vote to determine license renewal. In addition to its use in agriculture, Roundup is also sold to consumers for household use.

LAST UPDATED 10.25.2017