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 (SI) defines the sievert (Sv) as the unit of radiation dose equivalent, chronic radiation levels and standards are still often given in unts of millirems (mrem), where 1 mrem equals 1/1000 of a rem and 1 mrem equals 0.01 mSv. Light radiation sickness begins at about 50–100 rad (0.5–1 gray (Gy), 0.5–1 Sv, 50–100 rem, 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 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 (mSv)	Duration	Hourly equivalent (μSv/hour)	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.[1]
0.01	Daily	0.4	Natural background radiation, including radon[2]
0.06	Acute	-	Chest X-ray (AP+Lat)[3]
0.07	Acute	-	Transatlantic airplane flight.
0.09	Acute	-	Dental X-ray (Panoramic)[3]
0.1	Annual	0.011	Average USA dose from consumer products[4]
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 (0.5 in Denver due to altitude)[4]
0.28	Annual	0.032	USA yearly dose from natural terrestrial radiation (0.16-0.63 depending on soil composition)[4]
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[2]
0.7	Acute	-	Mammogram[3]
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[2][5]
1.1	Annual	0.13	1980 average USA radiation worker occupational dose[2]
1.2	Acute	-	Abdominal X-ray[3]
2	Annual	0.23	USA average medical and natural background Human internal radiation due to radon, varies with radon levels[4]
2	Acute	-	Head CT[3]
3	Annual	0.34	USA average dose from all natural sources[2]
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]
5	Annual	0.57	USA NRC occupational limit for minors (10% of adult limit) USA NRC limit for visitors [6]
5	Pregnancy	0.77	USA NRC occupational limit for pregnant women
6.4	Annual	0.73	High Background Radiation Area (HBRA) of Yangjiang, China[7]
7.6	Annual	0.87	Fountainhead Rock Place, Santa Fe, NM natural
8	Acute	-	Chest CT[3]
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[2] Abdominal CT[3]
14	Acute	-	^18F FDG PET scan,[8] Whole Body
50	Annual	5.7	USA NRC/ Canada CNSC occupational limit for designated Nuclear Energy Workers[5](10 CFR 20)
100	5 years	2.3	Canada CNSC occupational limit over a 5-year dosimetry period for designated Nuclear Energy Workers[5]
100	Acute	-	USA EPA acute dose level estimated to increase cancer risk 0.8%[2]
120	30 years	0.46	Exposure, long duration, Ural mountains, lower limit, lower cancer mortality rate[9]
150	Annual	17	USA NRC occupational eye lens exposure limit
175	Annual	20	Guarapari, Brazil natural radiation sources
250	2 hours	125 000	(125 mSv/hour) Whole body dose exclusion zone criteria for US nuclear reactor siting[10] (converted from 25 rem)
250	Acute	-	USA EPA voluntary maximum dose for emergency non-life-saving work[2]
260	Annual	30	Calculated from 260 mGy per year peak natural background dose in Ramsar[11]
400-900	Annual	46-103	Unshielded in interplanetary space.[12]
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.[5] Low-level radiation sickness due to short-term exposure
750	Acute	-	USA EPA voluntary maximum dose for emergency life-saving work[2]
1000	Hourly	1 000 000	(1000 mSv/hour) level reported during Fukushima I nuclear accidents, in immediate vicinity of reactor[13]
3000	Acute	-	Thyroid dose (due to iodine absorption) exclusion zone criteria for US nuclear reactor siting[10] (converted from 300 rem)
4800	Acute	-	LD50 (actually LD50/60) in humans from radiation poisoning with medical treatment estimated from 480 to 540 rem.[14]
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.[15]
5000			5 000 - 10 000 mSv. Most commercial electronics can survive this radiation level.[16]
20 000	Acute	2 114 536	Interplanetary exposure to solar particle event (SPE) of October 1989.[17][18]
21 000	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.[15]
48 500	Acute	-	Roughly calculated from the estimated 4500 + 350 rad dose for fatality of Russian experimenter on 1997 June 17 at Sarov.[15]
60 000	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.[15]
100 000	Acute	-	Roughly calculated from the estimated 10000 rad dose for fatality at the United Nuclear Fuels Recovery Plant on 1964 July 24.[15]
200 000		170 000	For over 1100 hours (170 mSv) Some Chernobyl emergency workers' doses[13]
1 000 000 000			The most radiation-hardened electronics can survive this radiation level.[19]

Comparison of Radiation Doses - includes the amount detected on the trip from Earth to Mars by the RAD on the MSL (2011 - 2013).^{[20][21][22][23]}

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 a interplanetary dose for a Carrington event at 34 - 45 Gy depending on type of flare spectrum and using a 1 gram/cm² aluminium shield (3.7 mm thick). Dose can be decreased down to 3 Gy through the use of a 10 gram/cm² alumunium shield (3.7 cm thick).

References

1. "Annex B: Exposures from natural radiation sources" (PDF). UNSCEAR 2000 Report: Sources and Effects of Ionizing Radiation. 1 Sources. p. 88, Figure 3.
2. Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/tb-a-2.pdf)
3. Health Physics Society (http://www.hps.org/documents/meddiagimaging.pdf)
4. Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/appa.htm)
5. Radiation Protection Regulations, Canada
6. "Annex B: Exposures from natural radiation sources" (PDF). UNSCEAR 2000 Report: Sources and Effects of Ionizing Radiation. 1 Sources. Orvieto town, Italy
7. Tao Z, Cha Y, Sun Q (July 1999). "[Cancer mortality in high background radiation area of Yangjiang, China, 1979–1995]". Zhonghua Yi Xue Za Zhi (in Chinese) 79 (7): 487–92. PMID 11715418.
8. "Radiation Exposure from Medical Exams and Procedures" (PDF). Health Physics Society. Retrieved 2015-04-19.
10. 10 CFR Part 100.11 Section 1
11. Dissanayake C (May 2005). "Of Stones and Health: Medical Geology in Sri Lanka". Science 309 (5736): 883–5. doi:10.1126/science.1115174. PMID 16081722. high as 260 mGy/year
12. R.A. Mewaldt; et al. (2005-08-03). "The Cosmic Ray Radiation Dose in Interplanetary Space – Present Day and Worst-Case Evaluations" (PDF). 29th International Cosmic Ray Conference Pune (2005) 00, 101-104. p. 103. Retrieved 2008-03-08.
13. "Japan's Chernobyl". Spiegel. 2011-03-14. Retrieved 16 March 2011.
14. Biological Effects of Ionizing Radiation
15. "A Review of Criticality Accidents" (PDF). Los Alamos National Laboratory. May 2000. pp. 16, 33, 74, 75, 87, 88, 89. Retrieved 16 March 2011.
16. ieee.org - Radiation Hardening 101: How To Protect Nuclear Reactor Electronics
17. Lisa C. Simonsen and John E. Nealy (February 1993). "Mars Surface Radiation Exposure for Solar Maximum Conditions and 1989 Solar Proton Events" (PDF) (published 2005-06-10). p. 9. Retrieved 2016-04-09.
18. "Successive Solar Energetic Particle Events in the October 1989" (published 2016-02-17). 1995-08-28. p. 140. Retrieved 2016-04-09.
19. "RD53 investigation of CMOS radiation hardness up to 1Grad" (PDF). Retrieved April 3, 2015.
20. Kerr, Richard (31 May 2013). "Radiation Will Make Astronauts' Trip to Mars Even Riskier". Science 340 (6136): 1031. doi:10.1126/science.340.6136.1031. Retrieved 31 May 2013.
21. Zeitlin, C. et al. (31 May 2013). "Measurements of Energetic Particle Radiation in Transit to Mars on the Mars Science Laboratory". Science 340 (6136): 1080–1084. Bibcode:2013Sci...340.1080Z. doi:10.1126/science.1235989. Retrieved 31 May 2013.
22. Chang, Kenneth (30 May 2013). "Data Point to Radiation Risk for Travelers to Mars". New York Times. Retrieved 31 May 2013.
23. Gelling, Cristy (June 29, 2013). "Mars trip would deliver big radiation dose; Curiosity instrument confirms expectation of major exposures". Science News 183 (13): 8. Retrieved July 8, 2013.