Diagnostic radiography: what are the risks

X-rays at the doses used in diagnostic radiography are associated with two main hazards: an increased risk of neoplasia in the individual exposed and an increased risk of hereditary disease in his or her progeny. The magnitude of these risks and some of the influencing factors are discussed. The product of the organ dose received in an examination, and the risk coefficient for that organ, can be used to estimate the risk of carcinogenesis or mutagenesis attributable to that examination, depending on the age of the patient. Cumulative data are presented which compares the extra incidence of cancer of the bone marrow, breast, lung and thyroid expected from irradiation of a 30-year-old in 14 different radiographic examinations, with their natural incidence during his or her life. It also compares the extra incidence of serious hereditary defects appearing in the first two generations after exposure of either parent, with the natural incidence of similar hereditary defects in pregnancies not exposed to other risks. It is concluded that the risk of radiation-induced damage is small but real and the use of X-rays should be kept to a minimum wherever possible. (UK)