Artificial Radioactivity

Artificial radioactivity: the price of better medicine

Editorial revision 2026

For about a century, humans have been exposed to sources of radiation other than natural radioactivity, which nevertheless remains the main source of exposure. Most of these new sources are beneficial. We receive more radiation than our ancestors as a result of advances in medicine. The additional doses remain modest.

The dominant share of medical exposure

Apart from personnel who are exposed to ionising radiation as a result of their work and from accidental situations, the additional dose comes almost entirely from medical examinations and certain therapies.
On average, medical diagnostic procedures in France result in an effective dose of approximately 1.57 millisieverts (mSv) per individual per year. It is estimated that there are 70 million radiology procedures (or procedures using ionising radiation) per year. IRSN 2024 report on 2022 values. This is a slight increase compared with 2017 (1.53 mSv).
This value is in the upper third of the average values of European Union countries and is much lower than that of the European country whose population is the most exposed, Belgium (2.7 mSv per year per inhabitant).
These are averages, as doses naturally vary greatly from one person to another, depending on age and state of health. It is difficult to reduce these doses other than by improving equipment. Giving up X-rays, CT scans and nuclear medicine examinations would mean giving up the advances of modern medicine.
However, ionising radiation is used only when justified. When it is justified, it is used as effectively as possible. Doses are limited according to the objective to be achieved. In radiation protection, the principles of justification, optimisation and justification are the rule for exposure to non-natural ionising radiation.

Nuclear power and other contributions: low exposures …

Of the 1.6 mSv from non-natural sources, the contribution from non-medical sources is estimated at 0.050 mSv. Contrary to a widespread belief, fallout from nuclear energy and atomic testing represents on average only 0.020 mSv, or 1 to 2% of the total. This low figure results from the precautions taken in reactor cores to isolate the radioactive materials present behind several protective barriers. People living near a nuclear reactor receive three times less radiation from it per year than they do during a transatlantic flight.
Thus, the annual collective dose released by a PWR reactor, which supplies electricity to approximately one million inhabitants in France, is equivalent to the natural radioactivity received by around thirty people.

The treatment of highly radioactive fuel discharged from nuclear power plants prevents it from being dispersed. Its conditioning, compaction and storage at protected sites ensure that it has no impact on the environment, at least on a human timescale.

After the Second World War and during the Cold War, the major powers carried out tests in the development of atomic bombs and hydrogen bombs. These tests were conducted mainly in the open air during the 1950s and 1960s. They released radioactive nuclides into the atmosphere. After the 1960s, tests were conducted underground and were therefore less polluting. Exposure to these releases represented approximately two years of natural radioactivity. The dispersion of radioactive elements across the entire surface of the Earth and the passage of time have had their effect: doses resulting from nuclear test fallout are now a few millionths of a sievert.

The danger of radiation. An expert’s perspective: A distrust of Science, by Yvon Grall, professor emeritus of biophysics and nuclear medicine