ECOLOGICAL AND HYGIENIC ASSESSMENT OF NEW PESTICIDES FOR GRAIN CEREALS CHEMICAL PROTECTION

Abstract

Relevance. The use of pesticides in the national economy is to destroy or inhibit the growth of harmful plants and to protect crops from pathogens requires a mandatory assessment of their environmental hygienic hazard. Objective of our study is to assess the hazards of three new pesticides for cereal grains protection: amicarbazone from the chemical class of triazolinone compounds, bicyclopyrone from the class of tricetones and pydiflumetofen from the class of carboxamides, in terms of ecotoxicity and environmental behavior. Materials and methods. Hazard assessment of amicarbazone, bicyclopyrone and pydiflumetofen was performed on the basis of data sources on their physico-chemical characteristics, toxicometry parameters for different species of living things and indicators of environmental behavior. For potential hazards integral assess for terrestrial ecosystems an ecotox was calculated taking into account mammalian toxicity, persistence and maximum rate consumption. To identify the limiting section of migration, the mathematical modeling was performed in the systems "soil-water", "soil-plants" and "soil-atmospheric air". Results. Amicarbazone has been shown to be extremely toxic to algae and highly toxic to higher aquatic plants (HAP) (hazard class I), moderately toxic (class IV) to mammals, mildly toxic (class III) to birds, soil mesofauna and invertebrates, virtually non-toxic to bees and fish; bicyclopyrone - extremely toxic to HAP (class I) and moderately toxic (class II) to the most sensitive algae, mildly toxic (class III) to birds, fish and invertebrates and virtually non-toxic to other terrestrial fauna; pydiflumetofen is highly toxic (class I) to fish and invertebrates, moderately toxic (class II) to algae and HAP, virtually non-toxic to all terrestrial biota. Pydiflumetofen has been shown to be a highly resistant and poorly mobile in soil; amicarbazone is stable and mobile; bicyclopyrone is highly resistant in laboratory experiments and moderately stable in field experiments, its mobility varies in a wide range: from very mobile to less mobile in some soils. The danger for terrestrial biocenoses of all studied pesticides under different soil and climatic conditions is lower by (1–5) orders of magnitude in comparison with DDT; the lowest is the ecotoxicity of bicyclopyrone, the highest – pydiflumetofen. All test substances are highly stable in water. The leading section of their migration in environment is the system "soil – water of ponds" and in case of pydiflumetofen – "soil – plants" as well.

Keywords

• pesticides, ecotoxicity, stability, migration, hazard assessment