Annual Radiation Exposure in the United States
Radiation Source | Average Effective Dose (millisieverts) |
|---|---|
Naturally occurring radiation sources | |
Radon gas | 2.3 |
Other terrestrial sources | 0.2 |
Radiation from the sun and outer space | 0.3 |
Natural radioactive material in the body | 0.3 |
Subtotal | 3.1 |
Manufactured radiation sources | |
Diagnostic medical imaging* | 3.0 |
Consumer products | 0.1 |
Fallout from weapons testing | less than 0.01 |
Nuclear industry | less than 0.01 |
Subtotal | 3.1 |
Total annual exposure | 6.2 |
Other sources of radiation exposure (per incident) | |
Airline travel | 0.001–0.014/hour of flight |
Dental x-rays | 0.005 |
Chest x-ray (back-to-front view) | 0.02 |
Chest x-ray (two views: back-to-front and side-to-side) | 0.1 |
Mammography | 0.4 |
Computed tomography of the head | 2 |
Computed tomography of the chest, abdomen, or pelvis | 6-8 |
Barium enema | 8 |
Nuclear medicine (for example, a bone scan) | 4.2 |
* Average value. Most people receive much lower doses each year, from examinations such as dental x-rays and mammograms, whereas a smaller number of ill or injured people require numerous imaging tests and thus receive much larger doses. | |
Data from the National Council on Radiation Protection and Measurements. Ionizing radiation exposure of the population of the United States. NCRP Report No. 160 National Council on Radiation Protection and Measurements, Bethesda, MD, 2009. | |