Toxic Effects of Malathion and Endosulfan on Chick Embryo

Toxic effects of malathion and endosulfan to fertile chicken eggs were determined. In-jection of ۱.۲۵, ۲.۵, ۵.۰ and ۱۰.۰ mg/egg of malathion into yolk sac of fertile eggs prior to incubation caused mortality of ۱۰.۰, ۳۰.۰, ۸۳.۳۳ and ۹۳.۳۳% respectively. Similar trend was observed with injection of endosulfan doses. Malathion and endosulfan at ۱.۲۵ mg/egg caused no pronounced LD۵۰ increase in mortality as compared to control groups. The LD۵۰ values for these insecticides proved malathion to be more toxic than endosulf- an. The hypothesis that the dose response of viable embryo fitted a linear regression line was statistically acceptable. Combination of malathion and endosulfan increased the mor-tality rate as compared with either one alone. With either compound, an increased dose generally resulted in a decrease in embryonic body weight.