Actual problems of hygiene and toxicology of pesticides based on glyphosate

Introduction. For several decades, glyphosate has been one of the most widely used herbicides in the world, but the safety of glyphosate and its commercial formulations is still controversial.

Materials and methods. The parameters of acute oral and dermal toxicity of glyphosate in rats have been established. An irritant effect on the skin and mucous membranes of the eyes (rats, rabbits), a sensitizing effect on guinea pigs were studied. To establish the degree of damaging effect on the body during its long-term administration, there was made a study of the chronic effect of glyphosate acid and specially prepared soybeans at doses of 0, 0.15, 20, 200, 2000 and 20,000 ppm. The toxic effect was judged by changes in integral, hematological, biochemical and physiological parameters. After 12 months from the beginning of the experiment, pathomorphological studies of animals of all groups were performed. There was performed a complete necropsy of the bodies of rats.

Results. Based on the results of the studies, the parameters of toxicity and hazard class were established, according to the hygienic classification of pesticides and agrochemicals (MP 1.2.0235-21 dated February 15, 2021) of glyphosate acid when exposed to the body of warm-blooded animals.

Limitations. When setting the parameters of glyphosate acid toxicometry, the intragroup number of rats was 6–8 animals, depending on the tasks being solved, which is a sufficient reference sample.

Conclusion. Based on studies performed on laboratory animals, the maximum inactive level (NOEL) of glyphosate is confirmed to be 100 mg/kg body weight, which corresponds to 2000 mg/kg feed (ppm). The foregoing indicates that the dose of 2000 ppm is much higher than the MRLs of glyphosate in soy at the level of 20 ppm (100 times) and 0.15 ppm (more than l3,000 times). Thus, it can be concluded that the maximum allowable level of glyphosate in soy of 20.0 mg/kg does not have a harmful effect and does not represent a real risk to the population.

Compliance with ethical standards. Conclusion of the Ethics Committee of the Federal Scientific Center of Hygiene named after F.F. Erisman of the Federal Service for Supervision in Protection of the Rights of Consumer and Man Wellbeing, Mytishchi, 141014, Russian Federation, No. 11 dated September 26, 2022.

Contribution:
Rakitsky V.N. — research concept, research design, editing, approval of the final version of the article, responsibility for the integrity of all parts of the article;
Chkhvirkiya E.G. — the concept of the study, discussion of the article;
Miroshnikova D.I. — research concept, experiment, material preparation, literature review, statistical analysis, article writing;
Belyaeva N.N. — selection of indicators, stereometric and morphometric determination of indicators, statistical analysis, writing and discussion of the article;
Vostrikova M.V. — preparation of material, determination of some indicators with their stereometric and morphometric assessment, writing an article.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version. 

Conflict of interest. The authors declare no conflict of interest. 

Acknowledgement. The study had no sponsorship. 

Received: September 8, 2022 / Accepted: October 3, 2022 / Published: October 23, 2022