[Effects of radiation on man]

Living on Earth, man is subjected to a shower of radiation, of cosmic, telluric and internal origin. Variations in the level of radiation over time have left biological imprints; Man first learned about artificial radiation, then learned how to produce it, revolutionizing medical diagnosis and treatment, and producing huge quantities of energy, particularly electric energy. In les than a century, knowledge or radiobiology brought man to a good mastery of the use or radiation within precise norms. With the application of these norms, a corollary appeared: the halt in increasing incidences of cancer and leukemia, as had been the case for the pioneers in radiobiology at the beginning of the century. However, the notion persists that ionising radiation, even at insignificant doses, is dangerous for man. Recent advances concerning DNA repair, hormesis and cancerogenesis are reassuring with regard to the present standards The French Académie des Sciences has pronounced that the present rules "are prudent and ensure an appreciable margin of security".