Teratogenicity study of some pesticides in chicken embryos

The use of pesticides involves the risk of poisoning on wild animals. Teratological tests carried out on avian embryos provide useful data for environmental protection and facilitate the development of environment-friendly chemical plant protection techniques. A 30% dimethoate containing insecticide formulation (BI 58 EC) and a 20% benfluralin containing herbicide formulation (Flubalex) and a 960 g/l S-metolachlor containing herbicide formulation (Dual Gold 960 EC) were studied in chicken embryos after single administration by immersion and injection technique. Treatment was done on day 0 of incubation. Applied concentration of pesticides were 0.1% (dimethoate) and 2.05% (S-metolachlor) and 0.375% (benfluralin) corresponding to that used in plant protection practice. Test materials were injected into the air chamber in a volume of 0.1 ml/egg, or eggs were treated by the immersion technique for 30 min. at 37 degrees C. Evaluation was done on day 19 of incubation. Injection treatment: the administration of S-metolachlor and benfluralin did not result a significant decrease in the average body weight of embryos. At the same time the body weight of embryos significantly decreased because of single administration of dimethoate. The embryomortality increased markedly after the administration of test materials (S-metolachlor, benfluralin, dimethoate). Immersion treatment: the administration of S-metolachlor and benfluralin and dimethoate did not result a significant decrease in the average body weight of embryos. The rate of embryomortality was low after the administration of S-metolachlor, benfluralin and dimethoate. After the immersion and the injection treatment the incidences of developmental anomalies were sporadic. In summary it can be established that the injection treatment was more toxic than immersion technique of the test materials in our study.