Review of studies analysing glyphosate and aminomethylphosphonic acid (AMPA) occurrence in groundwater

Abstract

The herbicide glyphosate (N-phosphonomethylglycine) has been the most commonly applied herbicide worldwide for the past 40 years. This review aims to present and discuss the state of knowledge concerning groundwater contamination by glyphosate and its metabolite, aminomethylphosphonic acid (AMPA). A dataset of 48 reports and articles reporting glyphosate and AMPA detection in groundwater worldwide was constructed from published literature. Specific attention was given to the analysis of available studies on glyphosate and AMPA transport in groundwater to investigate groundwater contamination factors. The information presented in this review highlights detectable groundwater contamination in several countries globally, with many cases exceeding European groundwater quality standards. Both agricultural and non-agricultural applications of glyphosate can be significant sources of pollution, and proximity to agricultural fields is a significant risk factor. AMPA has two primary sources, glyphosate and amino polyphosphates, but very little information is available about the origin of AMPA detected in groundwater. Glyphosate and AMPA transport to groundwater can be significant in well-structured soils rich in macropores, where it generally occurs via preferential flow. An inverse relationship was highlighted between the groundwater depth and glyphosate and AMPA occurrence and concentration in groundwater; however, some discrepancies among the studies were identified. Heavy rainfall shortly after glyphosate application poses a high risk of its transport to groundwater. Seasonal trends in glyphosate and AMPA in groundwater, related to application timing, agronomic practices, and weather conditions, were also observed. Finally, risk-management measures are proposed.

A New Family of Macrocyclic Polyamino Biphenolic Ligands: Acid-Base Study, Zn(II) Coordination and Glyphosate/AMPA Binding

“…In 2017, the European Union (EU) controversially voted to re-license glyphosate use for a limited period of five years and a recent extension, until December 2023, was granted to allow the European Food Safety Authority (EFSA) to conclude its examination on this timely and debated issue. Analogously, raising concerns about the chronic toxicity associated with AMPA has led to its inclusion with PMG in pollution monitoring programs [16].…”

Association of Lifetime Exposure to Glyphosate and Aminomethylphosphonic Acid (AMPA) with Liver Inflammation and Metabolic Syndrome at Young Adulthood: Findings from the CHAMACOS Study

“…For example, microbial degradation of glyphosate in soil results in the accumulation of AMPA in soil, plants, and animal products. 18 AMPA is highly soluble in water, more persistent in the environment than glyphosate, 83 and therefore frequently detected at higher concentrations than glyphosate in most hydrological settings, with groundwater and soil water samples having the highest values. 81 Tracer studies in Canada have shown that AMPA in groundwater is mainly derived from glyphosate degradation rather than wastewater sources, such as those contaminated with phosphonates.…”

Glyphosate and AMPA have low mobility through different soil profiles of the prosecco wine production area: A monitoring study in north-eastern Italy

“…In fact, AF does not include the particular soil structure heterogeneity that might lead to sitespecific solute bypass. Moreover, it does not account for single heavy rainfall events, which could have had an effect on moving the herbicide through the soil matrix down to 70 cm depth (Carretta et al, 2021b). Finally, the finding of GLP and AMPA below 30 cm can be due to herbicide interception by the aboveground vegetation, its following translocation into belowground tissues, and its likely release by dead roots below the topsoil (Laitinen et al, 2007).…”