Impact of updating the non-radiation parameters in the ICRP 103 detriment model

Abstract

The radiation detriment in ICRP 103 is defined as the product of the organ-specific risk coefficient and the damage that may be associated with a cancer type or hereditary effect. This is used to indicate a weighted risk according to the radiation sensitivity of different organs and the severity of damage that may possibly arise. While the risk refers to radiation exposure parameters, the extent of damage is independent of radiation. The parameters that are not affected by radiation are lethality, impairment of quality of life, and reduced life expectancy, which are considered as quantities associated with the severity of disease or damage. The damage and thus the detriment appear to be mostly affected by lethality, which is the quotient of the age-standardized mortality rate to the incidence rate. The analysis of the detriment presented in this paper focuses on the influence of the lethality on the detriment from 1980 to 2012 in the USA and Germany. While the lethality in this period covering more than three decades has decreased approximately linearly by 30% (both USA and Germany), within the same period the detriment declined only by 13% in the USA and by 15% in Germany. If only based on these two countries, an update on the detriment parameters with reference to 2007, when ICRP 103 was released, would result in a reduced weighted risk, i.e. the radiation detriment would be reduced by 10 to 15% from originally 5.7% per Sv for the whole population to roughly 5% per Sv.

Do we really need the “detriment” for radiation protection?

“…1 ) does not depend on any radiation parameters. It is subject to a temporal trend that reflects the improved prognosis through advances in cancer diagnosis and therapy (Breckow et al 2018 ). This means that the detriment, i.e., the “radiation risk” may decrease over time, even if the nominal risk coefficient remains unchanged.…”

“…For a given cancer site, k is defined as the quotient of the age-standardized mortality rate and the corresponding age-standardized incidence rate. The relative loss of life expectancy L is the life lost due to this cancer normalized by the average life lost over all cancers (for further detail see Breckow et al 2018 ). Although L is not independent of k, it is, however, not expressed analytically as a function of k (at least not given explicitly in the ICRP formalism).…”

“…The unweighted mortality fraction corresponds to the angle bisector k (dotted line). Modified from Breckow et al ( 2018 ) …”

On harmonization of health risk indicators caused by ionizing radiation exposure and other harmful factors based on DALY estimates

“…Given that, issues related to harmonizing approaches to assessment of ra-diation risks and other health risks arise quite frequently and discussed independently [1,2]. In addition, recently it has often been noted that it is necessary to revise the assessment methodology and measures of radiation health risks that are currently applied [3][4][5][6]. When tackling multiple issues related to public healthcare organization and population health assessment, the expert society more and more often suggest a gradual transition from mortality-based health measures to more informative summary health measures based on calculating how many years of healthy life have been lost due to disease, disability or injury, that is, number of lost healthy life years without any limitations on activity, functionality, and working capacities [7,8].…”

“…Currently, a methodology applied to calculate most summary measures of population health 6 is based on analyzing age-sex-specific mortality rates due to various reasons and epidemiology of nonfatal diseases. For example, the profile of the "Public healthcare" national project contains certain targets fixed for the period 2019-2024 and some of them directly concern population health assessment (the first 4 targets) but all these targets are mortalitybased ones [23].…”