The strontium unit is a

unit Unit may refer to: Arts and entertainment * UNIT, a fictional military organization in the science fiction television series ''Doctor Who'' * Unit of action, a discrete piece of action (or beat) in a theatrical presentation Music * ''Unit'' (a ...

used to measure the amount of radioactivity from strontium-90, a radionuclide found in

nuclear fallout Nuclear fallout is the residual radioactive material propelled into the upper atmosphere following a nuclear blast, so called because it "falls out" of the sky after the explosion and the shock wave has passed. It commonly refers to the radioac ...

, in a subject's body. Since the

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, cultu ...

body absorbs strontium as if it were

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar t ...

, incorporating it into the skeleton, its presence is very common. One strontium unit is equal to one

picocurie The curie (symbol Ci) is a non-International System of Units, SI unit of Radioactive decay, radioactivity originally defined in 1910. According to a notice in ''Nature (magazine), Nature'' at the time, it was to be named in honour of Pierre Curie ...

from strontium-90 per

gram The gram (originally gramme; SI unit symbol g) is a unit of mass in the International System of Units (SI) equal to one one thousandth of a kilogram. Originally defined as of 1795 as "the absolute weight of a volume of pure water equal to th ...

of calcium (37

becquerel The becquerel (; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. For applications relatin ...

s per kilogram) in the subject's skeleton. The

United States National Academy of Sciences The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...

holds that the maximum safe measure of strontium-90 in a person is one hundred strontium units (3700 Bq/kg). The average American is estimated to have three to four strontium units. The strontium unit was formerly known briefly as the sunshine unit, a

doublespeak Doublespeak is language that deliberately obscures, disguises, distorts, or reverses the meaning of words. Doublespeak may take the form of euphemisms (e.g., "downsizing" for layoffs and "servicing the target" for bombing), in which case it is ...

term promoted by the

United States Department of Defense The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national sec ...

until public ridicule brought about its disuse. Among the sources of this outcry was a

George Carlin George Denis Patrick Carlin (May 12, 1937 – June 22, 2008) was an American comedian, actor, author, and social critic. Regarded as one of the most important and influential stand-up comedians of all time, he was dubbed "the dean of countercu ...

performance, released on the CD '' Parental Advisory: Explicit Lyrics'', during a passage on governmental euphemisms for dangerous or unethical activities: "The Pentagon actually measures nuclear radiation in something they call 'sunshine units'!"

References

{{Reflist Units of radiation dose Strontium

See also

References