China
Africa
Explore chapters and articles related to this topic
The Effects of Synthetic Phosphonates on Living Systems
Published in Richard L. Hilderbrand, The Role of Phosphonates in Living Systems, 2018
Glyphosine (N, N-bis[phosphonoethyl]glycine, Figure 7) is an analog of glyphosate but is used to accelerate ripening and increase the level of sucrose in sugar cane, Saccarum officinarum. The visible effects of its application are cessation of growth, chlorosis, and dessication; however, the mechanism of action is not known.118,146 At relatively high doses, glyphosine has effects which are similar to those of glyphosate; however, the effects are quantitatively smaller.146 Glyphosine has been shown to reduce 70-S ribosomes and chloroplastic ribosomal RNA, but to have no effect on photophosphorylation.147 Potential metabolites of glyphosine (glyphosate, aminomethylphosphonic acid, sarcosine, and glycine) reduced growth but had little effect on reducing dry weight accumulation or on stimulating phenylalanine ammonia-lyase. This indicates that the conversion of glyphosine to glyphosate is not rapid in intact seedlings or that the glyphosate is rapidly metabolized with concomitant decrease in concentrations.146
The impact and toxicity of glyphosate and glyphosate-based herbicides on health and immunity
Published in Journal of Immunotoxicology, 2020
Cindy Peillex, Martin Pelletier
Once in the environment, glyphosate is metabolized by microorganisms into aminomethylphosphonic acid (AMPA; known as its most active metabolite) and methylphosphonic acid (MPA) (Figure 1(B)) (Williams et al. 2000). Glyphosate and its metabolite AMPA can be found in soils, water, plants, food, and animals (Alferness and Iwata 2002; Caloni et al. 2016; El-Gendy et al. 2018). Glyphosate is detected in human urine, blood, and maternal milk, with urinary levels of 0.26–73.5 μg/L in exposed workers and 0.16–7.6 μg/L in the general population (Acquavella et al. 2004; Gillezeau et al. 2019). Glyphosate most likely enters the body via the dermal, oral and pulmonary routes (Martinez et al. 1990; Williams et al. 2000). Even if the dermal route allows a poor absorption (about 2%), it is the main reported route of entry in exposed farmers (Connolly et al. 2019). Glyphosate then seems to accumulate principally in the kidneys, liver, colon, and small intestine and is eliminated in the feces (90%) and urine within 48 h (Williams et al. 2000). Because of this omnipresence, its safety is of grave concern. Glyphosate has long been regarded as harmless allegedly because it targets an enzyme inexistent in animals, is supposedly degraded into CO2, and its formulation contains misleadingly-called “inert” ingredients. Nevertheless, there is growing literature that describes the risks for glyphosate and GBHs on human health (Vandenberg et al. 2017).
Pilot study evaluating inhalation and dermal glyphosate exposure resulting from simulated heavy residential consumer application of Roundup®
Published in Inhalation Toxicology, 2020
Jennifer S. Pierce, Benjamin Roberts, Daniel G. Kougias, Chris E. Comerford, Alexander S. Riordan, Kara A. Keeton, Heidi A. Reamer, Neva F. B. Jacobs, Jason T. Lotter
Limited information regarding the toxicokinetics of glyphosate following inhalation, oral, or dermal exposures exists (ATSDR 2019). Multiple studies reported dermal absorption of glyphosate as the primary exposure route during application (Acquavella et al. 2004; Connolly, Coggins, et al. 2019), despite evidence indicating low rates of skin penetration (< 5%) when administered dermally as a diluted aqueous solution (on monkeys or using an in vitro human skin model) (Wester et al. 1991; Lavy et al. 1992; Wester et al. 1996). Exposure via inhalation is thought to be low in humans (Jauhiainen et al. 1991). Following absorption, glyphosate does not accumulate in the organs or tissues of humans or rats and is rapidly excreted in urine and feces, principally as the parent compound (ATSDR 2019). While glyphosate does not undergo significant metabolism in humans (IARC 2015), a small amount (< 1%) is metabolized possibly by gut microbiota in mammals, including humans, to aminomethylphosphonic acid (AMPA), which is similarly excreted in urine and feces (U.S. EPA 1993; Williams et al. 2000; ATSDR 2019, 2020). The arithmetic mean biological half-life of glyphosate has been estimated to be 5.5, 10, and 7.25 h, respectively, based on unadjusted, creatinine-adjusted, and urinary excretion rate-adjusted urine samples collected from seven horticultural workers who applied glyphosate-containing products (Connolly, Jones, et al. 2019). Connolly and colleagues cautioned that ‘[a]lthough elimination kinetics from different uptake routes should be comparable, it is important to also consider the absorption kinetics’, including a possible delay in absorption via dermal exposure (Connolly, Jones, et al. 2019, p. 209).
Acute exposure of glyphosate-based herbicide induced damages on common carp organs via heat shock proteins-related immune response and oxidative stress
Published in Toxin Reviews, 2021
Yuanyuan Li, Weikai Ding, Xiaoyu Li
Glyphosate-based herbicide (GBH) is one of the most frequently used herbicides in the world (Nwani et al.2013). Glyphosate can be metabolized by glyphosate oxidoreductase to produce aminomethylphosphonic acid (AMPA) and glyoxylate, and also can be metabolized by several bacteria to produce sarcosine which is then converted to glycine and ammonia by sarcosine oxidase (Brewster et al.1991). The metabolites of glyphosate ultimately breaks down to carbon dioxide, water, and phosphonic acid. The toxicity of GBH in humans and animals is controversial worldwidely, as its mode of action is the inhibition of 5-enolpyruvoylshikimate-3-phosphate synthase, a key enzyme of shikimate pathway, which is absent in animals (Mottier et al.2013), so animals cannot be considered as target organisms and GBH has often been considered relatively nontoxic for them (Giesy et al.2000, Williams et al.2000). However, due to its high water solubility (12 g L − 1 at 25 °C), long half-life in the environment (vary from a few days to 60 days), and extensively use (Vereecken 2005), it is frequently detected in aquatic ecosystems, sometimes at high concentrations (0.1–0.7 mg/L) (Botta et al.2009, Puértolas et al.2010) and many cases of acute poisoning and death of animals have been reported over the past few decades (Paganelli et al.2010, Guilherme et al.2012, Koller et al.2012), therefore, its toxicity must be studied thoroughly. Even though the negative impacts of GBH on different aquatic organisms about biochemical and physiological parameters have been studied, but there are few literatures available on the immunotoxicity in fish caused by glyphosate (Çavaş and Könen 2007, Modesto and Martinez 2010b, Kreutz et al.2010, 2011, Kondera et al.2018), and the effects of glyphosate-induced immunotoxicity in fish were not completely elucidated.