Translocation Studying of the Index of the Hazard of 2-Methyl-4-Chlorophenoxyacetic Acid in Hygienic Rating

Abstract

Introduction. The implementation of new pesticides into agricultural practice is possible only after their comprehensive toxicological and hygienic study and hygienic regulation, which is the basis for the preventing their adverse effects on the health of workers and the population, as well as on the environment. The rationale for the maximum allowable concentration of the pesticide’s active substance in the soil is based on the study of the main hazard indices established experimentally. The translocation hazard index in the soil-plant system, along with other indices of hazard (migrational-water, migrational-air and general-sanitary) in soil-water, soil-air and soil-microbiocenosis systems, reflects one of the indirect effects of xenobiotics on the contacting medium, by which the limiting index of the maximum allowable concentration of the pesticide’s controlled active ingredient is established. Material and methods. At this stage, studies have been carried out to investigate the translocation hazard index characterizing migration processes of the pesticide based on the active substance 2-methyl-4-chlorophenoxyacetic acid (phenoxyacetic acid class) from the soil to plants. The studies were performed with taking into account the observance of the requirements for carrying out experimental studies in standard, comparable soil and microclimatic conditions, and also in accordance with the principle of the extremality, which contributes the maximum migration of the studied chemical to the media (water, air, plant) in contact with the soil. To obtain a scientifically grounded threshold concentration of the substance of this hazard index, the study was carried out using a special sealed climatic chamber with controlled conditions of the ranges of illumination, temperature, and humidity of the air. Results. Based on the obtained experimental data, the threshold concentration of the controlled active substance was determined according to the translocation hazard index, in which the accumulation of the substance by plant phytomass at the time of harvest does not exceed the maximum permissible level (MRL) for food products.