Management of Commercially Generated Radioactive Waste - U.S. ...

warrants use in determining public policy on radiation protection." But it further
E.3
cautions that "explicit explanation and qualification of the assumptions and procedures
involved in such risk estimates are called for to prevent their acceptance as scientific
dogna" (p. 97).
The BEIR Report makes estimates of both absolute risk (cancer deaths per unit of radia-
tion exposure) and relative risk (percentage increase above normal incidence of cancer
deaths per unit of radiation exposure). And for each of these approaches it assumes either
a 30-year or a duration-of-life interval following the latent period, during which risk
remains elevated for non-leukemic cancer. Separate risk estimates are derived for the
in utero, 0-9 years, and 10+ years age periods, reflecting presumed age differences in the
sensitivity to radiation. The derivation of these risk estimates and their application to
the U.S. population is summarized in the BEIR Report (p. 169) where the number of excess
cancer deaths per year in the U.S. population, because of continual exposure at a rate of
0.1 rem/yr, is estimated as:
* 1726 for the absolute risk model with 30-year risk plateau
* 2001 for the absolute risk model with duration-of-life risk plateau
* 3174 for the relative risk model with 30-year risk plateau
* 9078 for the relative risk model with duration-of-life risk plateau.
The exposure rate of 0.1 rem/yr employed in these estimates is in the range of doses
received from naturally occurring radiation sources in the continental U.S.
The BEIR Report risk estimates are shown in Table E.1.1, converted to a man-rem basis.
This conversion involved dividing the risk estimates of Table 3-1, page 169, of the BEIR
Report, by 20,000,000, since the U.S. population, taken as 200,000,000, if exposed to
0.1 rem/yr, receives a total annual exposure of 20,000,000 man-rem. The BEIR Report pro-
vides estimates for leukemia and for "all other cancers"; the "all other cancers" category
is further subdivided for the absolute risk model as applied to those aged 10 or more.
Values for bone and lung cancer are shown in Table E.1.1 as though the apportionment applied
to the total population. It is important to note that the approximately five-fold range of
values for total cancer deaths predicted by the four different BEIR Report models do not
define a range between maximum and minimum possible values. They are merely four estimates,
based on different assumptions, between which it is not possible to make a confident choice
based on present knowledge.
The Environmental Protection Agency (EPA) in its Environmental Analyses of the Uranium
Fuel Cycle (EPA 1973, 1976) chose single risk estimates, based on the BEIR Report, which it
considered" the best available for the purpose of risk-cost benefit analyses, [while caut-
ioning that] they cannot be used to accurately predict the number of casualties" (EPA 1973,
p. C-14). These EP.A risk estimates, expressed as cancer deaths per million man-rem, are
also listed in Table E.1.1. The derivation of these numbers is not detailed in the EPA pub-
lications, but they'continue to be used by the EPA and have been adopted by others.