Orders of magnitude (radiation)
Recognized effects of higher acute radiation doses are described in more detail in the article on radiation poisoning. Although the International System of Units defines the sievert as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in units of millirems, 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.
The following table includes some dosages for comparison purposes, using millisieverts . The concept of radiation hormesis is relevant to this table – radiation hormesis is a hypothesis stating that the effects of a given acute dose may differ from the effects of an equal fractionated 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.
Level | Level in standard form | Duration | Hourly equivalent | Description |
0.001 | Hourly | 1 | Cosmic ray dose rate on commercial flights varies from 1 to 10 μSv/hour, depending on altitude, position and solar sunspot phase. | |
0.01 | Daily | 0.4 | Natural background radiation, including radon | |
0.06 | Acute | - | Chest X-ray | |
0.07 | Acute | - | Transatlantic airplane flight. | |
0.09 | Acute | - | Dental X-ray | |
0.1 | Annual | 0.011 | Average USA dose from consumer products | |
0.15 | Annual | 0.017 | USA EPA cleanup standard | |
0.25 | Annual | 0.028 | USA NRC cleanup standard for individual sites/sources | |
0.27 | Annual | 0.031 | Yearly dose from natural cosmic radiation at sea level | |
0.28 | Annual | 0.032 | USA yearly dose from natural terrestrial radiation | |
0.46 | Acute | - | Estimated largest off-site dose possible from March 28, 1979 Three Mile Island accident | |
0.48 | Day | 20 | USA NRC public area exposure limit | |
0.66 | Annual | 0.075 | Average USA dose from human-made sources | |
0.7 | Acute | - | Mammogram | |
1 | Annual | 0.11 | Limit of dose from man-made sources to a member of the public who is not a radiation worker in the USA and Canada | |
1.1 | Annual | 0.13 | 1980 average USA radiation worker occupational dose | |
1.2 | Acute | - | Abdominal X-ray | |
2 | Annual | 0.23 | USA average medical and natural background Human internal radiation due to radon, varies with radon levels | |
2 | Acute | - | Head CT | |
3 | Annual | 0.34 | USA average dose from all natural sources | |
3.66 | Annual | 0.42 | USA average from all sources, including medical diagnostic radiation doses | |
4 | Duration of the pregnancy | 0.6 | Canada CNSC maximum occupational dose to a pregnant woman who is a designated Nuclear Energy Worker. | |
5 | Annual | 0.57 | USA NRC occupational limit for minors USA NRC limit for visitors | |
5 | Pregnancy | 0.77 | USA NRC occupational limit for pregnant women | |
6.4 | Annual | 0.73 | High Background Radiation Area of Yangjiang, China | |
7.6 | Annual | 0.87 | Fountainhead Rock Place, Santa Fe, NM natural | |
8 | Acute | - | Chest CT | |
10 | Acute | - | Lower dose level for public calculated from the 1 to 5 rem range for which USA EPA guidelines mandate emergency action when resulting from a nuclear accident Abdominal CT | |
14 | Acute | 18F FDG PET scan, Whole Body | ||
50 | Annual | 5.7 | USA NRC/ Canada CNSC occupational limit for designated Nuclear Energy Workers | |
100 | 5 years | 2.3 | Canada CNSC occupational limit over a 5-year dosimetry period for designated Nuclear Energy Workers | |
100 | Acute | - | USA EPA acute dose level estimated to increase cancer risk 0.8% | |
120 | 30 years | 0.46 | Exposure, long duration, Ural mountains, lower limit, lower cancer mortality rate | |
150 | Annual | 17 | USA NRC occupational eye lens exposure limit | |
170 | Acute | Average dose for 187 000 Chernobyl recovery operation workers in 1986 | ||
175 | Annual | 20 | Guarapari, Brazil natural radiation sources | |
250 | 2 hours | 125 000 | Whole body dose exclusion zone criteria for US nuclear reactor siting | |
250 | Acute | - | USA EPA voluntary maximum dose for emergency non-life-saving work | |
260 | Annual | 30 | Calculated from 260 mGy per year peak natural background dose in Ramsar | |
400-900 | 4– | Annual | 46-103 | Unshielded in interplanetary space. |
500 | Annual | 57 | USA NRC occupational whole skin, limb skin, or single organ exposure limit | |
500 | Acute | - | Canada CNSC occupational limit for designated Nuclear Energy Workers carrying out urgent and necessary work during an emergency. Low-level radiation sickness due to short-term exposure | |
750 | Acute | - | USA EPA voluntary maximum dose for emergency life-saving work | |
1000 | Hourly | 1 000 000 | Level reported during Fukushima I nuclear accidents, in immediate vicinity of reactor | |
3000 | Acute | - | Thyroid dose exclusion zone criteria for US nuclear reactor siting | |
4800 | Acute | - | in humans from radiation poisoning with medical treatment estimated from 480 to 540 rem. | |
5000 | Acute | - | Calculated from the estimated 510 rem dose fatally received by Harry Daghlian on 1945 August 21 at Los Alamos and lower estimate for fatality of Russian specialist on 1968 April 5 at Chelyabinsk-70. | |
5000 | . Most commercial electronics can survive this radiation level. | |||
16 000 | Acute | Highest estimated dose to Chernobyl emergency worker diagnosed with acute radiation syndrome | ||
20 000 | Acute | Interplanetary exposure to solar particle event of October 1989. | ||
Acute | - | Calculated from the estimated 2100 rem dose fatally received by Louis Slotin on 1946 May 21 at Los Alamos and lower estimate for fatality of Russian specialist on 1968 April 5 Chelyabinsk-70. | ||
Acute | - | Roughly calculated from the estimated 4500 + 350 rad dose for fatality of Russian experimenter on 1997 June 17 at Sarov. | ||
Acute | - | Roughly calculated from the estimated 6000 rem doses for several Russian fatalities from 1958 onwards, such as on 1971 May 26 at the Kurchatov Institute. Lower estimate for a Los Alamos fatality in 1958 December 30. | ||
Acute | - | Roughly calculated from the estimated 10000 rad dose for fatality at the United Nuclear Fuels Recovery Plant on 1964 July 24. | ||
The most radiation-hardened electronics can survive this radiation level. | ||||
Hourly | 70 000 000 000 000 | Estimated dose rate for the inner wall in ITER |