## 3 Result Statements from the Analysis of the Available Literature
### Fate of Glyphosate in the Environment and Its Toxic Effects on Organisms  
As the global population continues to expand, the growing demand for food production needs to be supported by an efficient and sustainable agricultural system. The innovations of efficient herbicides and herbicide-tolerant genetically modified (GM) crops represent one of the solutions that not only protect plants from weeds but also increase worldwide crop production, leading to both economic and labor benefits [123; 124]. However, the introduction of GM crops is also causing an increase in herbicide use, leading to chemical pollution in soil, water, and air [125]. Moreover, an adaptive evolutionary processes act in weeds develops resistance against herbicides over time, thereby requiring higher amounts to control resistant weed strains. This implies that having herbicide-tolerant GM crops nearby would increase the risk of exposure to the higher levels of herbicides [126; 127; 128]. A typical example of herbicide-tolerant GM crops is genetically modified glyphosate-tolerant plants, which are designed to tolerate glyphosate, an active ingredient of a broad-spectrum and non-selective organophosphate herbicide. Glyphosate-based herbicides (GBHs) have become one of most widely applied herbicides worldwide in terms of volume due to their various advantages in terms of utility and economy [129; 130]. Their extensive application in agriculture received considerable attention in many countries such as Argentina, Brazil, Canada, and the United States of America due to the intense cultivation of glyphosate-tolerant GM plants [131; 132; 133; 134; 135; 136]. GBHs' overuse could be confirmed by the residue concentrations of glyphosate and its primary microbial metabolite product (aminomethylphosphonic acid; AMPA) in Argentina--this being up to almost 100 mg/kg, which is almost a fivefold increase compared to the maximum residue limit for soybeans used in feed and food [137; 138]. Additionally, a glyphosate residue concentration of 1481 \(\pm\) 73 \(\upmu\)g/L--exceeding the legally permitted maximum contaminant level (MCL) in drinking water regulated by the European Union, 0.1 \(\upmu\)g/L, by approximately 15,000-fold--was reported in natural water in Brazil [139; 140]. GBHs are intentionally applied to the foliar part of undesired plants; however, the uncontrolled application of GBHs could contaminate soils in and around the treated areas and be transformed into metabolites by biodegradation, photo-degradation, and complex chemical reactions [141]. AMPA, the main metabolite of glyphosate, can present toxic effects similar to original compounds [142]. The half-life of glyphosate depends on the physical and chemical properties of the external environment. In natural freshwater, it is estimated to be more than 60 days [143]. In seawater, it could persist for at least 47 days under low-light conditions at 25 \({}^{\circ}\)C, increase to 267 days in dark environments at 25 \({}^{\circ}\)C, and to 315 days in the dark at 31 \({}^{\circ}\)C prior to being metabolized by seawater microorganisms [144]. When sprayed GBHs and AMPA enter soils, several transport mechanisms are present that reduce the spreading of the contamination (Figure 3). GBHs' molecules could be taken up by plant tissues, resulting in biotransformation products, particularly AMPA, and their accumulation in the tissues [145]. In addition, the molecules could be immobilized through sorption onto soil particles, organic matter, and clay minerals or lost to the atmosphere through volatilization and vaporization and ultimately redeposited into environments via drops of rain [146; 147]. The molecules that could not bind strongly with, or desorb from, soil particles tend to leach into groundwater basins or dissolve and suspend in runoff waters [148; 149; 150]. Strongly bound GBH and AMPA molecules could also be moved off site to waters by water erosion [147].