Dose-related health risks
X-ray medical imaging. Dose and X-ray sources

Published around 2010, the following figures are often quoted to underline the importance of the dose. These are orders of magnitude, estimated on a worldwide scale:

• number of X-ray radiology procedures/year: ~ 3 billion (10% involve children);

• number of dental radiology procedures/year: ~ 350 million ;

• number of nuclear imaging procedures/year: ~ 37 million ;

• number of X-ray radiology units: ~ 1 million.

If we take radiotherapy into account (7.5 million procedures per year), we arrive at a cumulative effective dose equal to 20 times the health impact of Chernobyl – of course spread over an infinitely greater number of individuals!

In public health terms, radiation is considered ionizing above 12 eV (wavelength: 0.1 mm), which is the limit between ultraviolet and X-rays. The hard X-rays used in...