Risk Assessment of Glyphosate Exposures from Pilot Study with Simulated Heavy Residential Consumer Application of Roundup^® using a Margin of Safety (MOS) Approach

Abstract

Due to the widespread application of glyphosate, a nonselective herbicide, to a variety of resistant food crops, the general population is exposed to glyphosate through dietary intake. Despite this, dietary exposures to glyphosate are considered low in comparison to application‐related exposures. Although previous studies have evaluated exposure to horticultural and agricultural workers, to date only one study, which we recently conducted, has characterized exposure to glyphosate in consumers following heavy residential application of a glyphosate‐containing herbicide in a residential yard and garden setting. In this previous study, we demonstrated that urinary glyphosate concentrations in these applicators were similar to or in some circumstances greater than those in occupational applicators, likely due to the nature of the simulation study, which ensured a heavy application protocol. However, it is unknown whether these urinary glyphosate concentrations in consumer applicators correspond to internal doses that may be of concern. Therefore, the purpose of this study is to provide a comprehensive risk assessment of glyphosate exposure in consumer applicators using a margin of safety approach. Here, we incorporated data collected from multiple spot urine samples across time from our previous study that assessed consumer exposure to glyphosate from Roundup® application. Estimated internal doses, even with the use of conservative assumptions across unique approaches, were below internal doses estimated from established health‐based guidance values. Overall, this study demonstrates that glyphosate exposure from even heavy consumer application of a commercially available glyphosate‐containing herbicide does not appear to be a health concern.

Biological Monitoring of Glyphosate Exposure among Knapsack Sprayers in Khon Kaen, Thailand

“…Renal function markers in sugarcane farmers were lower, while urinary biomarkers of tubular injury, KIM-1 and NGAL, were higher, both of which indicate diminishing kidney function. Glyphosate was significantly correlated with ACR, eGFR, and NGAL [35].…”

“…The internal daily doses of all participants were lower than the RfD, which was assumed to be 1 mg/kg b.w./day based on the U.S. EPA standard [12]. Previously published reports on the internal dose of glyphosate sprayers in the inhalation and dermal exposure groups showed ratios of 0.139-1.165 µg/kg b.w./day and 0.214-4.736 µg/kg b.w./day, respectively [35,36]. One family-farm exposure study reported that the highest estimated internal dose was 0.0006 mg/kg b.w./day [19].…”

Advances in turfgrass weed management

“…Acetic acid herbicide solutions work as contact herbicides, offering short-term weed control, but they are known to burn skin and cause serious-to-severe eye injury, including blindness (Webber et al, 2018). In comparison, glyphosate is a systemic herbicide better able to kill weeds than acetic acid (Domenghini, 2020) without risk to the applicator (Kougias et al, 2021), and without risk of developing any form of cancer, including non-Hodgkin's lymphoma (Andreotti et al, 2018). Regulation of existing technology (e.g.…”