User:Chazzidy Harper/Glyphosate

Lead: Toxicity of glyphosate on biological systems ( Daphnia Magna )
Analyzing the toxicity interactive drug-drug effects of glyphosate on the biological system of daphnia magna using different multigenerational and sublethal effects. The drug-drug interaction effect depends on the chemical composition of glyphosate and the its complex.

Article body:
The use of glyphosate to control invasive plant species in wetland ecosystems has increased in recent decades. Although glyphosate is considered “environmentally safe,” repeated use can increase toxicological risks due to diffuse contamination of surface and groundwater into untargeted vegetation. Acute toxicity of glyphosate shows significant discrepancies and variability over several orders of magnitude. Plastic pollution is an environmental problem that pervades even the most remote aquatic and terrestrial habitats, and microplastics in particular pose an uncertain threat to living organisms. Being able to ameliorate the toxicity of contaminants such as the herbicide glyphosate on the biological system of daphnia magna, in addition to the potential direct adverse effects of microplastics, will allow insight into the interactive drug-drug effects. The drug-drug interaction effect depends on the chemical composition of glyphosate. ( 1)

Acute and multigenerational effects of individual and combined toxicity of polystyrene nanoplastics and glyphosate to the freshwater crustacean Daphnia magna. The combined individual toxicity of glyphosate and polystyrene nanoplastics is enhanced when present as a mixture. This indicates a synergistic effect between the components of the mixture, es when he simultaneously exposed to glyphosate and polystyrene nanoplastics at high toxic dose levels. A mixture of polystyrene nanoplastics and glyphosate caused increased immobility, and decreased swimming activity. Multigenerational responses showed that exposure of F0 daphnids as a mixture to Gly and PSNP affected F1 and F2 reproductive parameters. Contrary to the initial hypothesis that the mixture of polystyrene nanoplastics and glyphosate is additive, compounds indicate that glyphosate showed a synergistic effect of polystyrene nanoplastics. This finding provides important information on the interactions between hydrophilic organic pollutants and nanoplastic pollutants in freshwater ecosystems. Furthermore, the results are inconsistent with the hypothesis that the effects of exposure to individual ingredients or mixtures are not carried over to future generations of daphnids after exposure to individual ingredients or mixtures is removed. As the observed effects of the mixtures did not significantly exceed the expected values, they are considered to exhibit additive effects. In contrast, values ​​greater than the expected values are considered to indicate synergy, as the observed effect of the mixture was significantly higher than expected.(2)

Sublethal exposure to glyphosate Cu(II) complexes altered the behavior of D. magna. Glyphosate Cu(II) altered swimming speed, acceleration, distance traveled, and inactivity. The glyphosate-Cu(II) complex was more toxic to D. magna than glyphosate alone. Glyphosate is likely a mediator of aquatic metal toxicity and vice versa. Behavioral responses indicated that exposure of D. magna to a mixture of glyphosate and Cu(II) attenuated acute metal toxicity but increased apparent glyphosate toxicity upon complexation with Cu(II). Although the metal is often found naturally in the environment, it can also be found as a contaminant in many surface waters where glyphosate is also present. Unfortunately, little is known about the bioavailability and ecotoxicity of glyphosate metal complexes. Several studies suggest that glyphosate metal complexes may increase bioaccumulation of the metal, leading to altered toxicity compared to the parent compound (Duke and Powles, 2008, Tsui et al. 2005).(4) A mixture of glyphosate and Cu(II) complexes are believed to be highly stable in water and may lead to altered toxicity profiles compared to glyphosate alone (Morillo et al., 1997, Tsui et al., 2005). ( 5) This suggests that newer glyphosate formulations may contain levels of additives that contribute only marginally to toxicity compared to the active ingredient, glyphosate. (3)

References:
Zocchi, & Sommaruga, R. (2019). Microplastics modify the toxicity of glyphosate on Daphnia magna. The Science of the Total Environment., 697. https://doi.org/10.1016/j.scitotenv.2019.134194 ( 1)

Individual and combined multigenerational effects induced by polystyrene nanoplastic and glyphosate in Daphnia magna (Strauss, 1820),Science of The Total Environment, Volume 811,2022, https://doi.org/10.1016/j.scitotenv.2021.151360. ( 2)

Hansen, L. R., & Roslev, P. (2016). Behavioral responses of juvenile Daphnia magna after exposure to glyphosate and glyphosate-copper complexes. Aquatic Toxicology, 179, 36–43. https://doi.org/10.1016/j.aquatox.2016.08.010 ( 3)


 * Duke and Powles, 2008 S.O. Duke, S.B. Powles Glyphosate: a once-in-a-century herbicide Pest Manag. Sci., 64 (2008), pp. 319-325 https://doi.org/10.1002/ps.1518 (4)
 * Martin T.K. Tsui, L.M. Chu,Aquatic toxicity of glyphosate-based formulations: comparison between different organisms and the effects of environmental factors,Chemosphere,Volume 52, Issue 7,2003,https://doi.org/10.1016/S0045-6535(03)00306-0. (5)