Comparing two methods of examination in the interaction study of a pesticide and a heavy metal.

ABSTRACT

The use of pesticides in field application involves the risk of poisoning wild animals. The reproduction period of pheasant takes place at the same time as the spraying time of pesticides, which justifies, that we evaluate in a point of the ecotoxicologic view the influence of the pesticide on progressive avian embryo. The most frequent technical way is injecting the exam stuffs to the some part of the embryonated eggs under the bird teratological trials. The advantage of this method is that it can be injected in a correct measured dose into the optional part of eggs. The disadvantage of this method is that it can't model properly the influence on the environment. If adverse effect of the embraced chemical substance on the embryo is experienced under the study, it will be necessary to use an immersion treatment. This procedure shows only the possible indirect influence of the pesticide on the embryo but it can suitably model its influence in plant protection practice. Treatment was done on day 12 of incubation. Applied concentration of heavy element (Cd sulphate) was 0.01% and the concentration of pesticide (Dithane M-45) was 0.2%. Evaluation was done on day 19 of incubation. Injection treatment the simultaneous administration of Cd sulphate and the 80% mancozeb containing fungicide formulation on day 12 of incubation did not result in a significant decrease in the average body weight of embryos compared to neither the control nor the pesticide individually treated group. At the same time the body weight of embryos significantly decreased because of combined administration as compared to the Cd sulphate treated group. The embryo mortality and the incidence of developmental anomalies markedly increased after the simultaneous administration. Immersion treatment the combined administration of Cd sulphate and the mancozeb containing fungicide formulation on day 12 of incubation did not result in a significant decrease in the average body mass of embryos compared to neither the control nor the individually treated groups. The number of embryo mortality was very high after the simultaneous administration. The incidence of developmental anomalies was sporadic.