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Radiation Thermometer - Text Version

The following is a text version of the radiation thermometer tool. The purpose of the radiation thermometer is to put common radiation doses in perspective. This tool can help people assess their own risk in a radiation emergency. An interactive version of the thermometer tool can be found here.

Data Points

Rem (rem) Millisievert (mSv) DESCRIPTOR
1000 10,000 Dose that results in death for 100% of those who receive it.[1] People who are close to the site of a radiation emergency may be at risk for this dose.
400 4,000 Dose that results in death for 50% of those who receive it.[1] People who are close to the site of a radiation emergency may be at risk for this dose.
100 1,000

Lowest dose that could cause acute radiation syndrome.[1]

Dose for which risk of getting a fatal cancer increases from about 22% (average risk of cancer in United States) to about 27%.derived from [2]

50 500 Dose that causes damage to blood cells.[6,7]
2 20 Recommended threshold for relocating people (if projected dose from radioactive contamination is greater for the coming year, relocate).[8]
1 10 Dose received during a typical CT (Computerized Tomography) scan.[3]
0.62 6.2

Average dose per year for people in the U.S.[3] from:

  • naturally occurring background radiation – 310 mrem
  • medical exposures – 300 mrem
  • consumer products – 10 mrem
0.01 0.1 Typical dose from a chest x-ray.[3]
0.0035 0.035 Dose from high altitude solar and cosmic radiation during a flight from New York City to Los Angeles.derived from [9]
0.0005 0.005 Typical dose from a dental x-ray (bitewing and full mouth survey).[5]


[1] CDC. Acute radiation syndrome: A fact sheet for physicians [online]. 2013. Available from URL:

[2] National Research Council of the National Academies, Committee to Assess Health Risks from Exposure to Low Levels of Ionizing Radiation. Health risks from exposure to low levels of ionizing radiation: BEIR VII, Phase 2 [online]. 2006. Available from URL:

[3] National Council on Radiation Protection and Measurements (NCRP). Ionizing radiation exposure of the population of the United States. NCRP 2009;160.

[4] U.S. Food and Drug Administration (FDA). Trends in mammography dose and image quality 1974-2009 [online]. 2014. Available from URL:

[5] Gibbs SJ. Effective dose equivalent and effective dose: Comparison for common projections in oral and maxillofacial radiology. Oral Surg Oral Med Oral Path Oral Radiol Endod 2000;90(4):538-545.

[6] Eisenbud M, Gesell T. Environmental radioactivity. 4th ed. Oxford (UK): Academic Press; 1997.

[7] Mettler F, Upton A. Medical effects of radiation. 2nd ed. Philadelphia: W.B. Saunders; 1995.

[8] U.S. Environmental Protection Agency (EPA). PAG manual: Protective action guides and planning guidance for radiological incidents (draft for interim use and public comment) [online]. 2013. Available from URL:

[9] U.S. Department of Transportation (DOT), Federal Aviation Administration Advisory Circular. Radiation exposure of air carrier crewmembers – FAA AC 120-52 [online]. 1990. Available from URL: