GENOTOXICITY OF MODEL COMBINATIONS OF PESTICIDE ACTIVE INGREDIENTS IN TESTS ON BACTERIA SALMONELLA TYPHIMURIUM AND MOUSE BONE MARROW ERYTHROCYTES IN VIVO

Studies of the impacts of pesticide mixtures on non-target organisms and public health are important in view of the increasing number of pesticide formulations containing two or more active substances entering the market, the widespread use of pesticides in tank mixtures, as well as multiple treatments of crops with formulations of compounds belonging to different chemical classes. Objective. To evaluate the genotoxic activity of combinations of technical grade active ingredients of pesticides. Material and methods. The genotoxicity of 4 combinations of technical grade products of pesticide active ingredients (generics) was evaluated: thiamethoxam/triticonazole; glyphosate/cypermethrin; ethofumesate/phenmedipham/desmedipham; imidacloprid/imazalil/thiabendazole/tebuconazole using the bacterial reverse mutation test (Ames test) and the cytogenetic test based on the assessment of micronucleus incidence in mouse bone marrow polychromatic erythrocytes in vivo. Results. The combinations of thiamethoxam/triticonazole, glyphosate/cypermethrin and imidaclo-prid/imazalil/thiabendazole/tebuconazole did not show mutagenic activity in the Ames test and clas-togenic and aneugenic effects on the erythrocytes of mammalian bone marrow, which indicates their genetic safety. A mixture of ethofumesate, phenmedipham and desmedipham caused a weak genotoxic effect, inducing a dose-dependent, statistically significant increase in the incidence of micronucleated polychromatic erythrocytes in the mouse bone marrow. Discussion. The observed genotoxic activity in vivo may be due to the synergistic effect of ethofumesate, phenmedipham and desmedipham, as each of the technical grade active ingredients separately did not induce micronuclei at doses up to 2000 mg/kg body weight. Conclusion. Studies have confirmed the genetic safety of the three assessed pesticide combinations. However, some technical products of the active ingredients of analogous (generic) pesticides included in the same formulation and non-genotoxic individually may have a genotoxic effect in combination. The data indicate the importance of testing not only individual active ingredients but also their combinations.

pesticides, combinations, genotoxicity