Environmental and Toxicological Impacts of Glyphosate with Its Formulating Adjuvant

Authors: I. Székács, Á. Fejes, S. Klátyik, E. Takács, D. Patkó, J. Pomóthy, M. Mörtl, R. Horváth, E. Madarász, B. Darvas, A. Székács

Abstract:

Environmental and toxicological characteristics of formulated pesticides may substantially differ from those of their active ingredients or other components alone. This phenomenon is demonstrated in the case of the herbicide active ingredient glyphosate. Due to its extensive application, this active ingredient was found in surface and ground water samples collected in Békés County, Hungary, in the concentration range of 0.54–0.98 ng/ml. The occurrence of glyphosate appeared to be somewhat higher at areas under intensive agriculture, industrial activities and public road services, but the compound was detected at areas under organic (ecological) farming or natural grasslands, indicating environmental mobility. Increased toxicity of the formulated herbicide product Roundup compared to that of glyphosate was observed on the indicator aquatic organism Daphnia magna Straus. Acute LC₅₀ values of Roundup and its formulating adjuvant polyethoxylated tallowamine (POEA) exceeded 20 and 3.1 mg/ml, respectively, while that of glyphosate (as isopropyl salt) was found to be substantially lower (690-900 mg/ml) showing good agreement with literature data. Cytotoxicity of Roundup, POEA and glyphosate has been determined on the neuroectodermal cell line, NE-4C measured both by cell viability test and holographic microscopy. Acute toxicity (LC₅₀) of Roundup, POEA and glyphosate on NE-4C cells was found to be 0.013±0.002%, 0.017±0.009% and 6.46±2.25%, respectively (in equivalents of diluted Roundup solution), corresponding to 0.022±0.003 and 53.1±18.5 mg/ml for POEA and glyphosate, respectively, indicating no statistical difference between Roundup and POEA and 2.5 orders of magnitude difference between these and glyphosate. The same order of cellular toxicity seen in average cell area has been indicated under quantitative cell visualization. The results indicate that toxicity of the formulated herbicide is caused by the formulating agent, but in some parameters toxicological synergy occurs between POEA and glyphosate.

Keywords: Glyphosate, polyethoxylated tallowamine, Roundup, combined aquatic and cellular toxicity, synergy.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1091226

References:

[1] A. Székács and B. Darvas, "Forty Years with Glyphosate”. in Herbicides – Properties, Synthesis and Control of Weeds, M. N. A. E.-G. Hasaneen, Ed. Rijeka, Croatia: InTech, 2012, pp. 247–284.
[2] N. Amrhein, B. Deus, P. Gehrke, and H. C. Steinrucken, "The Site of the Inhibition of the Shikimate Pathway by Glyphosate. II. Interference of Glyphosate with Chorismate Formation in vivo and in vitro,” Plant Physiol., vol. 66, pp. 830–834, 1980
[3] G. M. Kishore and D. M. Shah, "Amino Acid Biosynthesis Inhibitors as Herbicides.” Annu. Rev. Biochem., vol. 57, pp. 627–663, 1988
[4] IFEN Report on Pesticides in Waters. Data 2003–2004, 2006
[5] J. W. van Valkenburg, "Terminology, Classification, and Chemistry,” in Adjuvants for Herbicides. , R. H. Hogdson, Ed. Champaign, IL, USA : Weed Science Society of America, 1982, pp. 1–9.
[6] D. K. Jones, J. I. Hammond, and R. A. Relyea, "Competitive Stress can Make the Herbicide Roundup More Deadly to Larval Amphibians,” Environ. Toxicol. Chem., vol. 30, pp. 446–454, 2010
[7] N. Benachour and G.-E. Séralini, "Glyphosate Formulations Induce Apoptosis and Necrosis in Human Umbilical, Embryonic, and Placental Cells,” Chem. Res. Toxicol., vol. 22, pp. 97–105, 2009
[8] H.-Y. Song, Y.-H. Kim, S.-J. Seok, H.-W. Gil, and S.-Y. Hong, "In vitro Cytotoxic Effect of Glyphosate Mixture Containing Surfactants,” J. Korean Med. Sci., vol. 27, pp. 711–715, 2012
[9] R. Mesnage, B. Bernay, and G.-E. Séralini, "Ethoxylated Adjuvants of Glyphosate-Based Herbicides are Active Principles of Human Cell Toxicity,” Toxicology, vol. 313, pp. 122–128, 2013
[10] Abraxis LLC, Glyphosate ELISA Kit PN 500086, Microtiter Plate (96T) http://www.abraxiskits.com/uploads/products/docfiles/184_PN500086USER.pdf Accessed: 24-Jan-2014
[11] M. Mörtl, Gy. Németh, J. Juracsek, B. Darvas, L. Kamp, F. Rubio, and A. Székács, "Determination of Glyphosate Residues in Hungarian Water Samples by Immunoassay,” Microchem. J., vol. 107, pp. 143–151, 2013
[12] International Organisation for Standardisation, Water quality. Determination of the Inhibition of Mobility of Daphnia magna Straus (Cladocera, Crustacea) – Acute Toxicity Test. ISO 6341:1996, Geneva, Switzerland, 1996
[13] C. F. Henderson and E. W. Tilton, "Tests with Acaricides against the Brow Wheat Mite,” J. Econ. Entomol., vol. 48, pp. 157–161, 1955
[14] M. Antoniou, M.E.M. Habib, C.V. Howard, R.C. Jennings, C. Leifert, R.O. Nodari, C.J. Robinson, and J. Fagan, "Teratogenic Effects of Glyphosate-Based Herbicides: Divergence of Regulatory Decisions from Scientific Evidence,” Environ. Anal. Toxicol., vol. S4, 006 doi: 10.4172/2161-0525.S4-006, 2012
[15] K. Schlett and E. Madarász, "Retinoic Acid Induced Neural Differentiation in a Neuroectodermal Cell Line Immortalized by p53 Deficiency,” J. Neurosci. Res., vol. 47, pp. 405–415, 1997
[16] T. Mosmann, "Rapid Colorimetric Assay for Cellular Growth and Survival: Application and Proliferation and Cytotoxicity Assays,” J. Immunol. Methods, vol. 65, pp. 55–63, 1983
[17] M. Gustafsson and M. Sebesta, "Refractometry of Microscopic Objects with Digital Holography,” Appl. Optics, vol. 43, pp. 4796–4801, 2004
[18] K. Alm, Z. El-Schich, M. Falck Miniotis, A. Gjörloff Wingren, B. Janicke, and S. Oredsson, "Cells and Holograms – Holograms and Digital Holographic Microscopy as a Tool to Study the Morphology of Living Cells,” in Holography – Basic Principles and Contemporary Applications", E. Mihaylova, Ed. Rijeka, Croatia: InTech, 2013, pp. 335–351.
[19] J. Sanchís, L. Kantiani, M. Llorca, F. Rubio, A. Ginebreda, J. Fraile, T. Garrido, and M. Farré, "Determination of Glyphosate in Groundwater Samples Using an Ultrasensitive Immunoassay and Confirmation by On-Line Solid-Phase Extraction Followed by Liquid Chromatography Coupled to Tandem Mass Spectrometry,” Anal. Bioanal. Chem., vol. 402, pp. 2335–2345, 2012
[20] R. A. Relyea, "The Lethal Impact of Roundup on Aquatic and Terrestrial Amphibians,” Ecol. Appl., vol. 15, pp. 1118–1124. 2005
[21] L. C. Folmar, J. O. Sanders, and A. M. Julin, "Toxicity of the Herbicide Glyphosate and Several of its Formulations to Fish and Aquatic Invertebrates,” Arch. Environ. Contam. Toxicol., vol. 8, pp. 269–278, 1979
[22] M. E. Sáenz, W. D. Di Marzio, J. L. Alberdi, and M. del Carmen Tortorelli, "Effects of Technical Grade and a Commercial Formulation of Glyphosate on Algal Population Growth,” Bull. Environ. Contam. Toxicol., vol. 59, pp. 638–644, 1997
[23] M. E. DeLorenzo, G .I. Scott, and P. E. Ross, "Toxicity of Pesticides to Aquatic Microorganisms: A Review,” Environ. Toxicol. Chem.., vol. 20, pp. 84–98, 2001
[24] T. H. Le, E. S. Lim, S. K. Lee, Y. W. Choi, Y. H. Kim, and J. Min, "Effects of Glyphosate and Methidathion on the Expression of the Dhb, Vtg, Arnt, CYP4 and CYP314 in Daphnia magna,” Chemosphere, vol 79, pp. 67–71, 2010
[25] R. Rico-Martínez, J. C. Arias-Almeida, I. A. Pérez-Legaspi, J. Alvarado-Flores, and J. L. Retes-Pruneda, "Adverse Effects of Herbicides on Freshwater Zooplankton. Herbicides – Properties, Synthesis and Control of Weeds.” in Herbicides – Properties, Synthesis and Control of Weeds, M. N. A. E.-G. Hasaneen, Ed. Rijeka, Croatia: InTech,, 2012, pp. 405–434.
[26] J. Z. Sandrini, R. C. Rola, F. M. Lopes, H. F. Buffon, M. M. Freitas, C. de M. G. Martins, and C. E. da Rosa, "Effects of Glyphosate on Cholinesterase Activity of the Mussel Perna perna and the Fish Danio rerio and Jenynsia multidentata. In vitro Studies,” Aquatic Toxicol., vol. 130–131, pp. 171–173, 2013
[27] G. L. Pérez, M. Solange Vera, and L. A. Miranda, "Effects of Herbicide Glyphosate and Glyphosate-Based Formulations on Aquatic Ecosystems,” in Herbicides – Properties, Synthesis and Control of Weeds , M. N. A. E.-G. Hasaneen, Ed. Rijeka, Croatia: InTech, 2012, pp. 334–368.
[28] L. Janssens and R. Stoks, "Synergistic Effects between Pesticide Stress and Predator Cues: Conflicting Results from Life History and Physiology in the Damselfly Enallagma cyathigerum,” Aquatic Toxicol., vol. 92-99., pp. 132–133, 2013
[29] R. M. Mann and J. R. Bidwell, "The Toxicity of Glyphosate and Several Glyphosate Formulations to Four Species of Southwestern Australian Frogs,” Arch. Environ. Contam. Toxicol., vol. 36, pp. 193–199, 1999
[30] P. J. Perkins, H. J. Boermans and G. R. Stephenson, "Toxicity of Glyphosate and Triclopyr Using the Frog Embryo Teratogenesis Assay – Xenopus,” Environ. Toxicol. Chem., vol. 19, pp. 940–945, 2000
[31] A. N. Edginton, P. M. Sheridan, G. R. Stephenson, D. G. Thompson, and H. J. Boermans, "Comparative Effects of pH and Vision® Herbicide on Two Life Stages of Four Anuran Amphibian Species,” Environ Toxicol. Chem., vol. 23, pp. 815–822, 2004
[32] C. M. Howe, M. Berrill, B. D. Pauli, C. C. Helbing, K. Werry, and N. Veldhoen, "Toxicity of Glyphosate-Based Pesticides to Four North American Frog Species,” Environ. Toxicol. Chem., vol. 23, pp. 1928–1938, 2004
[33] M. T. K. Tsui and L. M. Chu, "Aquatic Toxicity of Glyphosate-Based Formulations: Comparison between Different Organisms and the Effects of Environmental Factors,” Chemosphere, vol. 52, pp. 1189–1197, 2003
[34] J. Marc, M. Le Breton, P. Cormier, J. Morales, R. Bellé, and O. Mulner-Lorillon, "A Glyphosate-Based Pesticide Impinges on Transcription,” Toxicol. Appl. Pharmacol., vol. 203, pp. 1–8, 2005
[35] J. Brausch, B. Beall, and P. Smith, "Acute and Sub-Lethal Toxicity of Three POEA Surfactant Formulations to Daphnia magna,” Bull. Environ. Contam. Toxicol., vol. 78, pp. 510–514, 2007
[36] M. Cuhra, T. Traavik, and T. Bøhn, "Clone- and Age-Dependent Toxicity of a Glyphosate Commercial Formulation and Its Active Ingredient in Daphnia magna,” Ecotoxicology, vol. 22, pp. 251–262, 2013
[37] M. Sandbacka, I. Christianson, and B. Isomaa, "The Acute Toxicity of Surfactants on Fish Cells, Daphnia magna and Fish-A Comparative Study,” Toxicol In Vitro, vol. 14, pp. 61–68, 2000
[38] M. D. Waters, H. F. Stack, and M. A. Jackson, "Genetic Toxicology data in the Evaluation of Potential Human Environmental Carcinogens,” Mutat. Res., vol. 437, pp. 21–49, 1999
[39] C. D. S. Tomlin, Ed. The Pesticide Manual, 11th Edition, Brighton, UK: The British Crop Protection Council, 1997, pp. 646–649.
[40] M. Tu, C. Hurd, and J. M. Randall, Weed Control Methods Handbook: Tools & Techniques for Use in Natural Areas, Arlington, VA, USA: The Nature Conservancy, 2001 http://digitalcommons.usu.edu/govdocs/533 Accessed: 24-Jan-2014.
[41] Monsanto Company, Roundup® Classic. Material Safety Data Sheet, St. Louis, MO, USA: Monsanto Co, 2012.
[42] Monsanto Company, Roundup® Original. Material Safety Data Sheet, St. Louis, MO, USA: Monsanto Co, 1998.
[43] N. Benachour, H. Sipahutar, S. Moslemi, C. Gasnier, C. Travert, and G.-E. Séralini, "Time- and Dose-Dependent Effects of Roundup on Human Embryonic and Placental Cells,” Environ. Contam. Toxicol., vol. 53, pp. 126–133, 2007.
[44] C. Gasnier, C. Dumont, N. Benachour, E. Clair, M. C. Chagnon, and G.-E. Séralini, "Glyphosate-Based Herbicides are Toxic and Endocrine Disruptors in Human Cell Lines,” Toxicology, vol. 262, pp. 184–191, 2009.
[45] A. Paganelli, V. Gnazzo, H. Acosta, S. L. López, and A. E. Carrasco, "Glyphosate-Based Herbicides Produce Teratogenic Effects on Vertebrates by Impairing Retinoic Acid Signaling,” Chem. Res. Toxicol., vol. 23, pp. 1586–1595, 2010.