Major Category
Physical/Radiation
Description
Strontium is a soft, silver-gray metal with 4 stable isotopes. Strontium-90 is the only radioactive isotope with a half-life long enough to be an environmental concern. [Argonne]
Sources/Uses
Six atoms of Sr-90 are produced for every 100 fissions (6% yield). It is a waste product in spent nuclear fuel. Used as a generator of electricity for weather stations, buoys, and satellites; [Argonne] Used as a tracer in medicine and agriculture; Used in the treatment of bone cancer and eye diseases; It was widely dispersed as fallout from nuclear weapon testing in the 1950s and 1960s, but current levels in the environment are very low. [EPA Radionuclides] "It decays to Yttrium-90, which is a short-lived high energy β particle emitter, which greatly increases the radiological effect of 90Sr exposures." [Reference #2]
Comments
Source: Nuclear fission
Half-Life: 29 years
Effective Half-Life: 15 years
Specific Activity: 140 Ci/g
Decay Mode: Beta
GI Absorption: 30-40%
Lung Clearance Half-Time: Years for all insoluble compounds and SrTi03; Days for all soluble compounds except SrTi03;
Critical Organ: Bone
Internal Toxicity: Very High
Annual Limit on Intake: 0.004 mCi
Radiation Energy (MeV): Beta 0.546 (100%) + Y-90 daughters;
[See Glossary for references.] See "Radiation, ionizing."
Restricted
EPA standards limit Sr-90 in drinking water not to exceed 8 pCi/L. [HSDB]
Half Life
"The majority of 90Sr (> 50%) is rapidly cleared from the body within a week following exposure, only a small amount remains after a year, largely in the skeleton." [Reference #2]
Other Information
No other related information on this agent was found.