Americium

Agent Name
Americium
CAS Number
7440-35-9
Formula
Am
Major Category
Physical/Radiation
Category
Radionuclides
Description
A man-made, radioactive metal with a melting point of 1173 degrees C; [Merck Index] ". . . a silvery, ductile, very malleable, non-magnetic metal." [ATSDR ToxProfiles]
Sources/Uses
Americium is a byproduct of plutonium production in nuclear reactors. Americium-241 is used in smoke detectors and in industrial radiography; Also used with beryllium as a neutron source, and as a target material in nuclear reactors and accelerators to synthesize heavier elements; [Argonne] Used in medical diagnosis as a bone mineral analyzer; Used as a radiation source in the treatment of cancer; [Merck Index] A typical household smoke detector contains about 0.9 uCi of Am-241. [ATSDR ToxProfiles]
Comments
Most Important Radionuclide: Am-241;
Source: Beta decay of plutonium-241;
Half-Life: 430 years;
Effective Half-Life: 139 years;
Specific Activity: 3.5 Ci/g;
Decay Mode: Alpha;
GI Absorption: 0.05%;
Lung Clearance Half-Time: 10-100 days for all compounds;
Critical Organ: Bone;
Internal Toxicity: Very High;
Annual Limit on Intake: 0.000006 mCi;
Tenth-Value Layer: 0.4 mm Pb;
Gamma Ray Constant: 0.1 R/h @ 1 cm per mCi;
Radiation Energy (MeV): Alpha 5.48 (85%); Gamma 0.0595 (38%)
Radiation Accidents: 3 accidents including one at Hanford in 1976 in which worker survived a >1 mCi dose; 3 incidents of "Melting of Radioactive Materials";
[See Glossary for references.] See "Radiation, ionizing."
Biomedical References

Exposure Assessment

Diseases, Processes, and Activities Linked to This Agent

Other Information
No other related information on this agent was found.