Safety problems in radiography: units of radiation

Abstract

The energy absorbed from ionizing radiation when it is incident on living tissue can result in damage or destruction of the cells. The principal reactions are burns, dermatitis, cancer induction and blood changes, and there may be direct damage to chromosomes in individual cells which are responsible for reproduction. It is necessary, therefore, to consider both radiation-induced disease in the individual and genetic damage to part of the total population, which may affect future generations. Both types of damage are considered in fixing internationallyagreed dose limitations. At present it is assumed that there is no wholly safe dose of ionizing radiation, so the risk assumed by an individual or a population group must be balanced against the benefits derived from the uses of X-rays etc. An attempt is also made to ensure that the genetic consequence of the agreed dose limit, in the foreseeable future, has an acceptable limit. The International Committee for Radiological Protection (IRCP) is the international body from which recommendations on protection originate, and these are endorsed by national committees and made law in individual countries or by bodies such as the EC, sometimes with minor changes in the detail of recommended procedures. The international regulations are periodically updated [1–3].