2.1.1 Beginnings

It has been recognized since the beginning of the twentieth century, as a result of observations during early studies on X-rays and radioactive minerals, that exposure to high levels of radiation can cause clinical damage to the tissues of the human body. In recognition of the need to control radiation hazards and to protect workers, the International Commission on Radiological Protection (ICRP) was established in 1928 (although not named as such until 1950). Since then, long term epidemiological studies of populations exposed to radiation, for example, the survivors of the atomic bombing of Hiroshima and Nagasaki in Japan in 1945, medically exposed persons and some populations exposed to the fall-out from the Chernobyl accident in 1986, have demonstrated that exposure to radiation also has a potential for causing the delayed induction of malignancies. Successive recommendations of the ICRP have reflected the increasing knowledge of the harmful effects of ionizing radiation and the need to have a system that provides adequate protection to all who may be exposed to ionizing radiation both at work and in the environment. The recommendations of the ICRP have been accepted globally and form the basis of regulations for protection against the hazards of ionizing radiation in all the countries of the world. The most recent recommendations of the ICRP were issued as Publication 103 (ICRP, 2007). In forming its recommendations on radiological protection, the ICRP has taken into account the reviews and conclusions of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), in particular, in relation to the effects of ionizing radiation on humans (UNSCEAR, 2000 and 2010).