As I noted earlier, radiation levels at Japan's Fukushima power station have reached 400 millisieverts (mSv) per hour. The chart below (posted by @ gakuranman) helps put this figure into perspective.

Thus the radiation safety levels in many countries on Earth, are likely too conservative. This is good news for Mars colonists. The goal is not 6.2 mSv per year, but say 200 to 250 mSv / year. 41 ...

If astronauts on the moon are to avoid harmful radiation, long-term lunar bases will need to be shielded by 2 to 3 metres of regolith – the moon’s surface layer of rock and dust. Jingnan Guo ...

XKCD's radiation dose chart. Click to zoom in. As we know from XKCD's amazing Radiation Dose Chart (pictured above), we know that a dosage of around 100 mSv in a single year increases your chance ...

For instance, an aluminum slab with 2, 4, 10 cm thickness (corresponding to a mass thickness of approximately 5, 11, 27 g/cm2, respectively, which is the product of the density, 2.7 g/cm3, and ...

Employees performing dental radiography should not normally receive significant radiation dose provided normal radiation protection measures are employed, such as distance and shielding. A report from ...