Today, radiation protection is a major issue for the nuclear industry throughout the world,
particularly in France. The 2011 disaster of Fukushima Dai-ichi has brought back to public
attention questions about the risks associated with nuclear power for civilian purposes.
The risk of accidental release of radioactive molecules, including cesium-137 (137Cs), from
these facilities cannot be completely eliminated. The non-cancer-related health
consequences of chronic exposure to this radionuclide remain poorly understood. After
absorption, cesium is distributed throughout the body. The toxicity of 137Cs is due mainly
to its radiological properties. Studies in humans report that 137Cs impairs the immune
system and induces neurological disorders. Children appear more susceptible than adults
to its toxic effects. In animals, and most particularly in rodents, low-dose internal
contamination disrupts the sleep-wake cycle, but without behavioural disorders.
Impairment of the cardiovascular system has also been observed. Physiologic systems
such as the metabolism of vitamin D, cholesterol and steroid hormones are altered,
although without leading to the emergence of diseases with clinical symptoms. Recently,
a metabolomics study based on contamination levels comparable to those around
Chernobyl after the accident showed that it is possible to identify individual rats
chronically exposed to low doses of 137Cs, even though the exposure was too low to affect the standard clinical markers. In conclusion, the scientific evidence currently available,
particularly that from experimental animal models exposed to chronic contamination,
suggests that 137Cs is likely to affect many physiologic and metabolic functions. Thus, it
could contribute, with other artificial substances in the environment, to increasing the risk
of developing non-cancer diseases in some regions.