From MIT Nuclear Information Hub:
What are the health effects of various doses/dose rates?
Radiation dose is measured in Rad or Gy (1Gy = 100 Rad). However, the most often reported two units that have been mentioned in the media are Sievert (Sv) and Rem (1 Sv = 100 Rem). These are defined as dose equivalent, which accounts for the different effects each type of radiation have on the body. The Sievert and Rem are units used by regulatory authorities to control radiation release and exposure. The table below lists the different amount of radiation you can get from your normal activities.
| Source of Radiation | Dose in millirem (mrem) Dose Rate (mrem/hr) |
Dose in milliSv(mSv) or Dose Rate(mSv/hr) |
| Background Average in US |
~360 millirem per year (1 millirem per day) |
3.6 milliSievert |
| Chest X-ray | ~8 millirem per X-ray |
.08
milliSievert |
| CT scan of abdomen |
~800 millirem |
8 milliSievert |
| Cross Country flight in US |
2-5 millirem |
0.02-0.05 milliSievert |
| Regulatory limit for radiation workers |
5000 millirem per year |
50 milliSievert |
| note: 1 Rem = 1000 millirem: 1Sv = 1000 millisievert | ||
Related: the nuke fan club often distracts with talk about bananas (or flying or x-rays or granite rocks) being radioactive. It’s intuitively nonsense but momentarily confusing. Here’s a simple debunking: http://boingboing.net/2010/08/27/bananas-are-radioact.html