Computed Tomography (CT) is under special scrutiny because it has become the single largest contributor to man-made radiation exposure. Today, the radiation dose level from medical exposure is in the same range as the annual natural background radiation of 3.1 mSv. The same patterns are observed in all industrialized countries, and it can be expected that the pattern will be the same in other countries.
1 Sources and Effects of Ionizing Radiation, UNSCEAR 2008 Report. United Nations Scientific Committee on the Effects of Atomic Radiation, New York, 2010.