Human exposure to Glyphosate
Numerous publications demonstrate that human exposure to glyphosate is ubiquitous. Therefore, glyphosate and its main biodegradation product aminomethylphosphonic acid (AMPA) have been detected in the urine of farm workers and their families as well as the general population, e.g. urban dwellers and children.
Exposure occurs mainly via ingestion (food and water) and inhalation (of contaminated air) as well as via dermal absorption when in contact with contaminated surfaces or spraying. This is indicated by the observation that although urine levels of glyphosate of people strictly consuming organic food are significantly lower, than those living on conventional food, some traces of glyphosate are still detected. Potential exposures can also occur in people living, visiting or working in agricultural zones or pesticide treated areas.
When looking at the exposure levels in Europe, scientific studies indicate that adults are generally exposed to glyphosate but children end up having higher levels of exposure than adults. Overall, however, the exposure levels of the general European population remain rather low. Similarly, a population-wide monitoring study conducted in Germany examining the presence of glyphosate and its main metabolite AMPA in the urine samples of children and adolescents concluded that beside relatively low overall exposure to glyphosate, more than half of the 2144 urinary samples (52%) tested positive for glyphosate, and almost half tested positive for its metabolite AMPA (46%).
Although glyphosate exposure levels in the general population are low there is uncertainty in relation to the safe levels of exposure. Conolly et al. (2020) reviewing 21 studies monitoring human urinary concentrations of glyphosate and AMPA concluded: “Human exposures extrapolated from urinary glyphosate concentrations found that upper-bound levels may be much closer to the Acceptable Daily Intake than previously reported.“ And a recent study in U.S. farmers identified “an association between glyphosate exposure and oxidative stress”. This is remarkable because oxidative stress is a known mechanism that can lead to carcinogenesis.
Resources
Factsheets:
Friends of the earth (2013) : Human contamination by glyphosate
Articles:
Génération futures (January 2022): New scientific data on glyphosate, presence of glyphosate in urine
The Guardian (2022), Carey Gillam : ‘Disturbing’: weedkiller ingredient tied to cancer found in 80% of US urine samples
Food Watch (2021) : Glyphosate poison agricole dans le vin de AH, Jumbo et Lidl / Landbouwgif glyfosaat in wijn van AH, Jumbo en Lidl
Scientific research papers:
Simona Panzacchi et al., “The Ramazzini Institute 13-Week Study On Glyphosate-Based Herbicides At Human-Equivalent Dose In Sprague Dawley Rats: Study Design And First In-Life Endpoints Evaluation” (Environmental Health, 2018.).
Connolly A. et al., “Human Biomonitoring of Glyphosate Exposures: State-of-the-Art and Future Research Challenges”, (Toxics. 2020).
Gillezeau C, et al., “Update on human exposure to glyphosate, with a complete review of exposure in children”, (Environ Health. 2020).
Grau, D. et al., “Quantifiable urine glyphosate levels detected in 99% of the French population, with higher values in men, in younger people, and in farmers”, (Environ Sci Pollut Res 29, 2021).
Hofmann, F. et al., “Pesticides and pesticide-related products in ambient air in Germany”, (Environmental Sciences Europe, 33(1), 2021).
Lemke N, et al., “Glyphosate and aminomethylphosphonic acid (AMPA) in urine of children and adolescents in Germany - Human biomonitoring results of the German Environmental Survey 2014-2017 (GerES V)”, (Environ Int. 2021).
Lozano-Kasten F. et al., “Seasonal Urinary Levels of Glyphosate in Children From Agricultural Communities. Dose-Response”, (2021;19(4)).
Buekers, J., et al., “Glyphosate and AMPA in Human Urine of HBM4EU-Aligned Studies: Part B Adults”, (Toxics 2022).
Connolly A, et al., “A Human Biomonitoring Study Assessing Glyphosate and Aminomethylphosphonic Acid (AMPA) Exposures among Farm and Non-Farm Families”, (Toxics. 2022).
Vicky C Chang, and al., “Glyphosate exposure and urinary oxidative stress biomarkers in the Agricultural Health Study”, (Journal of the National Cancer Institute, 115(4), 2023).