Basis for Person-Sv (S) and Effective Dose per Individual in United States (EUS) in 2006, with Medical Exposure Being 3 mSv
| Exposure category | S | EUS (mSv) | EExp (mSv) |
| Ubiquitous background | 933,000 | 3.11 | 3.11 |
| Internal, inhalation (radon and thoron) | 684,000 | 2.28 | 2.28 |
| External, space | 99,000 | 0.33 | 0.33 |
| Internal, ingestion | 87,000 | 0.29 | 0.29 |
| External, terrestrial | 63,000 | 0.21 | 0.21 |
| Medical | 899,000 | 3.00 | —* |
| CT | 440,000 | 1.47 | —* |
| Nuclear medicine | 231,000 | 0.77 | —* |
| Interventional fluoroscopy | 128,000 | 0.43 | —* |
| Conventional radiography and fluoroscopy | 100,000 | 0.33 | —* |
| Consumer | 39,000 | 0.13 | 0.001–0.3† |
| Industrial, security, medical, educational, and research | 1,000 | 0.003 | 0.001–0.01† |
| Occupational | 1,400 | 0.005 | 1.1 |
| Medical | 550 | 0.8 | |
| Aviation | 530 | 3.1 | |
| Commercial nuclear power | 110 | 1.9 | |
| Industry and commerce | 110 | 0.8 | |
| Education and research | 60 | 0.7 | |
| Government, DOE, military | 40 | 0.6 | |
| Total | 1,870,000‡ | 6.2‡ |
↵* Not determined for medical category because only number of procedures is known, not number of patients exposed.
↵† Range of values for various subcategories in this category.
↵‡ Rounded values.
EExp= average effective dose for the exposed group for 2006; DOE = Department of Energy.
Table 8.1 of NCRP report 160 (1) provides more detail. Adapted with permission of (1).