This study we tried to investigate the effect of Cobalt radiation in lung of Wistar rats weighing 160 to 180 gr. A total of 60 rats were divided into 4 groups with 15 rats each.T1, First group as control group did not receive any radiation, T2) was irradiated with 5 Gy, T3) was irradiated with 7.5 Gy, T4) ws irradiated with 12 Gy. These findings demonstrate dosage d.ependent changes in different parts of the lung tissue. Histopathological studies of the lung revealed radiation-induced Edema, hyperemia can be seen in all the 3 groups and goes up as the dosage increases. Also, the thickening of alveolar walls through penetration of unicellular e.g. lymphocytes and macrophages are observed in animals of groups 3 and 4.
