Sequential study of the pathology of Prudhoe Bay crude oil in chicken embryos

Ten microliters of Prudhoe Bay crude oil was applied to the shell of fertile leghorn chicken eggs on Day 9 of incubation. Gross and microscopic pathological changes were examined in embryos surviving 1, 2, 4, and 9 days after treatment. Liver necrosis, renal lesions, and extensive edema appeared 2 days after treatment and reached maximal prevalence 4 days after treatment. There was minimal repair of the lesions from Day 4 to Day 9 after treatment. Pathological changes, including liver necrosis, mineralization in the kidney, infiltration by a large number of heterophils in the liver and spleen, subcutaneous edema with formation of large blisters, and reduction in body weight and length were still present on Day 18 of incubation, close to hatching time.