Recognized effects of higher acute
radiation doses are described in more detail in the article on
radiation poisoning. Although the
International System of Units
The International System of Units, known by the international abbreviation SI in all languages and sometimes pleonastically as the SI system, is the modern form of the metric system and the world's most widely used system of measurement. ...
(SI) defines the
sievert
The sievert (symbol: SvNot be confused with the sverdrup or the svedberg, two non-SI units that sometimes use the same symbol.) is a unit in the International System of Units (SI) intended to represent the stochastic health risk of ionizing rad ...
(Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of
millirems (mrem), where 1 mrem equals 1/1000 of a rem and 1 rem equals 0.01 Sv. Light radiation sickness begins at about 50–100
rad (0.5–1
gray (Gy), 0.5–1
Sv, 50–100
rem
Rem or REM may refer to:
Music
* R.E.M., an American rock band
* ''R.E.M.'' (EP), by Green
* "R.E.M." (song), by Ariana Grande
Organizations
* La République En Marche!, a French centrist political party
* Reichserziehungsministerium, in Nazi ...
, 50,000–100,000 mrem).
The following table includes some dosages for comparison purposes, using millisieverts (mSv) (one thousandth of a sievert). The concept of
radiation hormesis is relevant to this table – radiation hormesis is a
hypothesis
A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obse ...
stating that the effects of a given
acute dose may differ from the effects of an equal
fractionated
Fractionation is a separation process in which a certain quantity of a mixture (of gases, solids, liquids, enzymes, or isotopes, or a suspension) is divided during a phase transition, into a number of smaller quantities (fractions) in whi ...
dose. Thus 100 mSv is considered twice in the table below – once as received over a 5-year period, and once as an acute dose, received over a short period of time, with differing predicted effects. The table describes doses and their official limits, rather than effects.
See also
*
Mars Radiation Environment Experiment (MARIE)
External links
unh.edu: The Carrington event: Possible doses to crews in space from a comparable event received in 2004 and concludes an interplanetary dose for a
Carrington event
The Carrington Event was the most intense geomagnetic storm in recorded history, peaking from 1 to 2 September 1859 during solar cycle 10. It created strong auroral displays that were reported globally and caused sparking and even fires in mul ...
at 34 - 45 Gy depending on type of flare spectrum and using a 1 gram/cm
2 aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It ha ...
shield (3.7 mm thick). Dose can be decreased down to 3 Gy through the use of a 10 gram/cm
2 aluminium shield (3.7 cm thick).
References
{{Portal bar, Physics
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...