British medical X ray statistics and their relevance for radiation protection policies

The non-uniform manner in which medical X ray doses are distributed with respect to patient age and their potential for directly benefitting the health care of the patient, should both be taken into account when assessing the overall health detriment from diagnostic radiology. The collective dose from medical X rays is predominantly delivered to patients of middle age or older and it is estimated that, due to the delayed nature of stochastic radiation effects, the detriment per unit radiation dose to the X ray patient population is about 60% of that which would apply if the whole population were exposed at a uniform rate throughout life. It is also estimated that purely detrimental X ray exposures, i.e. those that make no beneficial contribution to health care, might contribute as much as 50% to the current collective dose from medical X rays. Consequently only 30% (60% of 50%) of the collective dose from medical X rays should perhaps be compared with other sources of radiation exposure of the population to estimate their relative health detriment and the appropriate allocation of radiation protection resources. (author)