The dissertation is devoted to the hygienic justification of measures to prevent the harmful effects on public health from new active substances in plant protection chemicals – herbicides amicarbazone from the class of triazolones, bicyclopyrone from the class of triketones and pydiflumetofen from the class of pyrazolecarboxamides, during their migration from the soil to adjacent environments: groundwater and surface water sources, agricultural plants, and the near- surface layer of atmospheric air.
Based on the analysis of informational sources regarding the toxic properties and toxicometric parameters of the studied substances, it was determined that, according to the current Ukrainian hygienic classification of pesticides (DSanPiN 8.8.1.2.002-98), amicarbazone is classified as hazardous (class II) with the limiting indicator being acute inhalation toxicity; bicyclopyrone is classified as moderately hazardous (class III) with limiting indicators including acute inhalation toxicity and remote action effects (carcinogenicity, teratogenicity, reproductive toxicity, and embryotoxicity); and pydiflumetofen is classified as hazardous (class II), with the limiting indicator being carcinogenic activity. All studied substances are highly persistent in soil (under laboratory aerobic conditions) and water (class I hazard). The degradation rate in soil increases in the order: pydiflumetofen – bicyclopyrone – amicarbazone. Regarding persistence in vegetating agricultural plants, amicarbazone and bicyclopyrone can be classified as moderately hazardous pesticides (class III), while pydiflumetofen is classified as both moderately hazardous (class III) and low hazardous (class IV). By the sorption coefficient normalized to organic carbon content in soil (Koc), amicarbazone is mobile (class II according to the SSLRC classification), pydiflumetofen is low mobile (class IV), and the mobility of bicyclopyrone varies widely from highly mobile (class I) to low mobile (class IV) in specific soils. The studied pesticides are non-volatile based on vapour pressure and Henry’s constant and are classified as low hazardous (class IV) according to the inhalation poisoning potential coefficient (IPPC, which is 6–8 orders of magnitude below 0.5) as per DSanPiN 8.8.1.2.002-98.
Based on the results of field experiments conducted in various agro-climatic zones of Ukraine with formulations containing amicarbazone and bicyclopyrone (herbicides
Vision WG and Acuron Uno 200 SL, РК for treating maize crops at application rates /a.r./ of 0.5 kg/ha and 0.75 L/ha, respectively) and pydiflumetofen (fungicides Miravis 200 SC, КС for treating onions and cucumbers at an a.r. of 0.5 L/ha, Miravis Neo 300 SE, СЕ for winter wheat at an a.r. of 1.0 L/ha, and Miravis Prime 400 SC, КС for strawberry and vineyard crops at an a.r. of 1.2 L/ha), the persistence parameters of the studied substances in soil were determined for the first time in Ukraine. It was established, that based on the disappearance time of 50 % of the initial amount of the substance, amicarbazone [DT50 is (13.5±0.7) days] and bicyclopyrone [DT50 is (18.3±1.9) days] are moderately persistent (class III hazard), while pydiflumetofen [DT50 is (103.3±16.4) days] is highly persistent (class I hazard) according to DSanPiN 8.8.1.2.002-98. The DT50 values in Ukrainian soils were significantly lower than the maximum values obtained in field studies in other countries (amicarbazone, bicyclopyrone, and pydiflumetofen – 87 days, 36 days, and 8540 days, respectively).
