Glyphosate exposure and urinary oxidative stress biomarkers in the Agricultural Health Study

Abstract

Background Glyphosate is the most widely applied herbicide worldwide, and its use has been associated with increased risks of certain hematopoietic cancers in epidemiologic studies. Animal and in vitro experiments suggest that glyphosate may induce oxidative stress, a key characteristic of carcinogens; however, evidence in human populations remains scarce. We investigated associations between glyphosate exposure and urinary oxidative stress biomarkers in the Biomarkers of Exposure and Effect in Agriculture study, a molecular epidemiologic subcohort in the Agricultural Health Study. Methods This analysis included 268 male farmers selected based on self-reported recent and lifetime occupational glyphosate use and 100 age- and geography-matched male non-farmers. Concentrations of glyphosate and oxidative stress biomarkers (8-hydroxy-2’-deoxyguanosine [8-OHdG], 8-iso-prostaglandin-F2α [8-isoprostane], and malondialdehyde [MDA]) were quantified in first-morning-void urine. We performed multivariable linear regression to evaluate associations of urinary glyphosate and self-reported glyphosate use with each oxidative stress biomarker. Results Urinary glyphosate concentrations were positively associated with levels of 8-OHdG (highest vs. lowest glyphosate quartile; geometric mean ratio [GMR]=1.15, 95% confidence interval [CI]=1.03-1.28, Ptrend=.02) and MDA (GMR = 1.20, 95% CI = 1.03-1.40, Ptrend=.06) overall. Among farmers reporting recent glyphosate use (last 7 days), use in the previous day was also associated with significantly increased 8-OHdG and MDA levels. Compared with non-farmers, we observed elevated 8-isoprostane levels among farmers with recent, high past 12-month, or high lifetime glyphosate use. Conclusions Our findings contribute to the weight of evidence supporting an association between glyphosate exposure and oxidative stress in humans and may inform evaluations of the carcinogenic potential of this herbicide.

Metabolomic Changes in Rat Serum after Chronic Exposure to Glyphosate-Based Herbicide

“…The IPA report predicted that the reduced level of epinephrine and increased level of L-arginine would contribute to the activation of urination disorder in the GBH-exposed rats. Chang et al [ 77 ], in their study, showed that there is a possible relationship between glyphosate exposure and urinary oxidative stress in farmers. Urination disorder has been reported to be associated with other health problems such as aging, bladder infection, blocked urinary tract from a tumor or kidney stone, and diabetes [ 78 ].…”

Relationship of urinary glyphosate concentrations with glycosylated hemoglobin and diabetes in US adults: a cross-sectional study

“…With a short elimination half-life( 5.5–10 h) [ 33 ], previous investigations have demonstrated that only a small fraction (1–6%) of ingested glyphosate is promptly removed in urine as an unaltered compound [ 34 , 35 ]. However, most studies have assessed human exposure to glyphosate by measuring glyphosate levels in urine [ 2 , 36 , 37 ]. Due to the widespread use of urinary glyphosate levels, it is comparable across populations by assessing urinary glyphosate levels.…”

“…Since the 1990s, the applications of glyphosate have increased rapidly worldwide [ 1 ]. Glyphosate is currently the most extensively used agricultural pesticide in both the United States (US) and the rest of the world [ 2 ].…”

Sensitive detection of herbicide residues using field-amplified sample injection coupled with electrokinetic supercharging in flow-gated capillary electrophoresis

“…1 Specically, a recent report demonstrated the association between GlyP exposure and oxidative stress by measuring oxidative biomarkers in urine samples of GlyP users, and oxidative stress is widely regarded as a key characteristic of carcinogens in cancer development. 6 Residues of GlyP and its major degradation product aminomethylphosphonic acid (AMPA) 7 can exist in plants, seeds and roots. A large fraction of GlyP present in soil comes from pesticide spraying or pesticides rain-washed from crops.…”

“…1 Specifically, a recent report demonstrated the association between GlyP exposure and oxidative stress by measuring oxidative biomarkers in urine samples of GlyP users, and oxidative stress is widely regarded as a key characteristic of carcinogens in cancer development. 6…”