Carcinogenic effects of transuranium elements

In this experiment, 544 wistar rats were used to study carcinogenic effects of 241Am, 239Pu, and 237Np in lung. These nuclides were injected into animals intravenously, subcutanously or by lung puncturation in doses of 0.2, 1.0, 5.0 and 8.5 μCi/kg, respectively. Serial pathological changes such as alveolar and bronchiolia metaphasia, adenomatosis and cancer in lung were found in animals injected by lung puncturation, but these changes were not seen in rats injected intravenously or subcutanously. Primary lung cancers were found in some animals about one year after intoxication. The incidence of primary lung cancers was about 4.2-10.0% in 241Am-poisoned rats, 4.0-14,0% in 239Pu-poisoned rats