The draft ICRP report, The Use of Effective Dose as a Radiological Protection Quantity, states that: “E may be used as an approximate indicator of possible risk, recognising that this is a pragmatic, but unintended, application of effective dose.” In other words, the world is to assume that effective dose can be used to predict risk, as it is frequently being used incorrectly today, even though that was never the original intent of the concept.
The draft report also states that: “It is made clear in this report that while doses incurred at low levels of exposure may be measured or assessed with reasonable accuracy, the associated risks are increasingly uncertain at lower doses. However, bearing in mind the uncertainties associated with risk projection to low doses, E may be considered as an approximate indicator of possible risk.” In other words, even though we do not know with any certainty the risk of radiation at low dose, we can still use effective dose to predict future risk.
These are two fallacious and incorrect deductions. Why?
Because mathematically, effective dose is not an indicator of future risk. It is also not "an approximate indicator of possible risk." These are both weak and unsupported statements.
This use of effective dose presupposes validity of the linear no-threshold dose-response model over all dose ranges (which rarely holds true) and applies only to an age-averaged, gender-averaged (male plus female), region-averaged reference model. The collective weaknesses in all assumptions underpinning calculation of effective dose clearly demonstrate that effective dose is neither numerically nor quantitatively predictive of risk or detriment, prospectively or retrospectively. Consequently, effective dose should not be used to predict individual or population risk of cancer at any dose level. Instead, individual assessments of potential detriment should only be based on organ or tissue radiation absorbed dose together with best scientific understanding of the appropriate absorbed dose response relationships and risk coefficients derived therefrom” (Fisher DR and Fahey FH, “Appropriate use of effective dose in radiation protection and risk assessment.” Health Physics 113(2):102-109; 2017).
Even though the Fisher and Fahey paper cited above on “Appropriate use of effective dose in radiation protection and risk assessment” is directly relevant to the draft ICRP document and was provided to the authors, it was not referred to or cited in the draft. This appears to be an unfortunate oversight by the ICRP.
The current draft on The Use of Effective Dose as a Radiological Protection Quantity upholds the false premise that effective dose is predictive of future cancer risk. That application was never the intended purpose of effective dose when originally proposed by Wolfgang Jacobi about three decades ago as a helpful "tool" for establishing primary and secondary limits.
One need only to search within the fundamental mathematical underpinnings of the effective dose construct, with the high uncertainties of each element of the calculation, and the many weak assumptions thereto pertaining, to understand that effective dose cannot predict future risk of cancer. However, it appears that ICRP would be endorsing inappropriate use with this document.
While I believe that effective dose can be used both appropriately and inappropriately, the current draft ICRP report justifies a wholly inappropriate interpretation should never be codified in formal guidance.