In acute studies of laboratory animals, plutonium causes radiation pneumonitis and bone marrow injury. Surviving animals have increased risk for lung fibrosis and cancer. [HSDB] Plutonium workers exposed to >10 Sv after acute inhalation exposures had increased risk for lung fibrosis. The inhalation exposures were "readily traced back to accidents or equipment failure" and the "clinical significance of plutonium-induced fibrosis remains to be determined." [
PMID 16038583] Plutonium is a toxic metal that may damage the kidneys. [EPA Radionuclides] "There is sufficient evidence in humans that inhalation of plutonium-239 aerosols causes lung cancer, liver cancer and bone sarcoma. Exposure to plutonium-239 also entails exposure to plutonium-240 and other isotopes." [IARC]
Most Important Radionuclide: Pu-239
Source: Neutron irradiation of Pu-238
Half-Life: 24,000 years
Effective Half-Life: 197 years
Specific Activity: 0.63 Ci/gm
Decay Mode: Alpha
GI Absorption: 0.05%
Lung Clearance Half-Time: Years for PuO2; Weeks for all other compounds;
Critical Organ: Bone
Internal Toxicity: Very High
Annual Limit on Intake: 0.000006 mCi
Radiation Energy (MeV): Alpha 5.16 (74%); Alpha 5.14 (15%)
Reported Radiation Accidents: 4 accidents with 6 injuries (Pu-239 and Pu-238) and 1 death (Pu-235);
[See Glossary for references.] See "Radiation, ionizing."