- a harmful radioactive isotope of strontium, produced in certain nuclear reactions and present in their fallout.
Origin of strontium 90
First recorded in 1950–55
Also called radiostrontium.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for strontium 90
It was established that strontium-90 and cesium-137, important in fallout on land, enter the marine cycles only in minute amounts.
Much attention has been devoted to strontium-90 and to its availability to man by deposit on plants and soils.
Experiments and fallout observations show that strontium-90 does not penetrate soils deeply.
If this is true, strontium-90 may be contained in the deep currents and eventually will be brought again to the surface.
- A radioactive isotope of strontium having a mass number of 90 and a half-life of 28 years. Strontium 90 is the most dangerous component of the fallout from nuclear explosions because it is easily absorbed by the body. It is also used in medicine to treat cancer.
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