We absorb radiation from a variety of sources. How much is too much? Experts say 3 mSv per year is probably OK for most of us; 20 mSv for those who must have medical tests.
| RADIATIONAMOUNT* | |
|
CT scan, full body |
10–12 mSv |
|
CT scan, chest or pelvis |
4–8 mSv |
|
Natural background radiation (from sunlight, radon gas, etc.) from living in high-altitude cities (e.g., Denver, Salt Lake City) |
6 mSv (per year) |
|
Natural background radiation from living at sea level (e.g., Chicago) |
3 mSv (per year) |
|
Mammogram |
1–2 mSv |
|
High-mileage frequent flying (100,000–450,000 miles per year) |
1–6.7 mSv |
|
X-ray of chest (or ankle to look for broken bones) |
0.1–0.6 mSv |
|
DEXA (bone-density) scan |
0.01–0.05 mSv |
|
Dental X-ray (bitewing) |
0.02 mSv |
|
Single airplane flight, coast-to-coast |
0.01–0.03 mSv |