Definition of a disability weight for human exposure to ionizing radiation and its application to the justification of medical exposure.

Objectives: To establish a link between radiation dosimetry and disability-adjusted life-years (DALY) with the aim of quantifying the justification of medical exposures. Methods: The health detriment, defined as lifetime loss of DALY at age of exposure to ionizing radiation for a US-European population was calculated. A simple model of the relationship was fitted to the results. Apart from in late life within the latency period for radiation-induced cancers, most of the relationship can be adequately fitted to a straight line of negative gradient. The gradient of this line corresponds to a loss of DALY per year following exposure to radiation and is therefore equivalent to a disability weight (DW) used in the calculation of DALY. Results: Radiation dose-dependent DWs for radiation exposure to a US-European population are estimated as 0.020 DALY/yr/Sv for males and 0.022 DALY/yr/Sv for females. Conclusions: By comparing a range of 66 radiological examinations in terms of the DWs of the disease or injury states with the DWs resulting from the associated radiological exposures, it is demonstrated graphically that the resulting benefit is far greater than the detriment in every case. Advances in knowledge: The definition of a DW for ionizing radiation, proportional to effective dose as currently defined, can link radiation exposure to the existing large body of data on the DALY burden and DWs for a wide range of diseases and injuries, providing a means for the quantitative justification of the benefit-detriment balance of medical exposures.