Orders of magnitude (radiation)

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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.[2]
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[citation needed]
0.25 Annual 0.028 USA NRC cleanup standard for individual sites/sources[citation needed]
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[citation needed]
0.48 Day 20 USA NRC public area exposure limit[citation needed]
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 [3]

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[citation needed]
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[citation needed]
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[citation needed]
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]

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[8]
150 Annual 17 USA NRC occupational eye lens exposure limit[citation needed][clarification needed]
175 Annual 20 Guarapari, Brazil natural radiation sources[citation needed]
250 2 hours 125000 (125 mSv/hour) Whole body dose exclusion zone criteria for US nuclear reactor siting[9] (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[10]
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[citation needed]

750 Acute - USA EPA voluntary maximum dose for emergency life-saving work[2]
1000 Hourly 1000000 (1000 mSv/hour) level reported during Fukushima I nuclear accidents, in immediate vicinity of reactor[11]
3000 Acute - Thyroid dose (due to iodine absorption) exclusion zone criteria for US nuclear reactor siting[9] (converted from 300 rem)
4800 Acute - LD50 (actually LD50/60) in humans from radiation poisoning with medical treatment estimated from 480 to 540 rem.[12]
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.[13]
5000 5 000 - 10 000 mSv. Most commercial electronics can survive this radiation level.[14]
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.[13]
48 500 Acute - roughly calculated from the estimated 4500 + 350 rad dose for fatality of Russian experimenter on 1997 June 17 at Sarov.[13]
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.[13]
100 000 Acute - roughly calculated from the estimated 10000 rad dose for fatality at the United Nuclear Fuels Recovery Plant on 1964 July 24.[13]
200 000 Hourly 170000 for over 1100 hours (170 mSv) Some Chernobyl emergency workers' doses[11]
1 000 000 000 The most radiation-hardened electronics can survive this radiation level.[15]
Comparison of Radiation Doses - includes the amount detected on the trip from Earth to Mars by the RAD on the MSL (2011 - 2013).[16][17][18][19]


References[edit]

  1. ^ "Annex B: Exposures from natural radiation sources". UNSCEAR 2000 Report: Sources and Effects of Ionizing Radiation. 1 Sources. p. 88, Figure 3. 
  2. ^ a b c d e f g h i Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/tb-a-2.pdf)
  3. ^ a b c d e f g Health Physics Society (http://www.hps.org/documents/meddiagimaging.pdf)
  4. ^ a b c d Oak Ridge National Laboratory (http://www.ornl.gov/sci/env_rpt/aser95/appa.htm)
  5. ^ a b c d e Radiation Protection Regulations, Canada
  6. ^ "Annex B: Exposures from natural radiation sources". 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. ^ [1]
  9. ^ a b 10 CFR Part 100.11 Section 1
  10. ^ 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 
  11. ^ a b "Japan's Chernobyl". Spiegel. 2011-03-14. Retrieved 16 March 2011. 
  12. ^ Biological Effects of Ionizing Radiation
  13. ^ a b c d e "A Review of Criticality Accidents". Los Alamos National Laboratory. May 2000. pp. 16, 33, 74, 75, 87, 88, 89. Retrieved 16 March 2011. 
  14. ^ ieee.org - Radiation Hardening 101: How To Protect Nuclear Reactor Electronics
  15. ^ Introduction to Radiation-Resistant Semiconductor Devices and Circuits
  16. ^ 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. 
  17. ^ 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. 
  18. ^ Chang, Kenneth (30 May 2013). "Data Point to Radiation Risk for Travelers to Mars". New York Times. Retrieved 31 May 2013. 
  19. ^ 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.