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

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124. (Page D.8) - The model used to estimate the population dose
literature has done nothing to dispel our belief that the use of a dose
rate reduction factor is ill advised as is the minimal plateau duration
commitment from carbon-14 is too conservative (i.e., overestimates the (30 years) used in the RSS.
impact). If dilution by the Suess effect is not considered and the
total number of health effects is integrated-over all time, the release The UNSCEAR 1977 Report suggests (except for leukemia) a 50-year
of 1.4 MCi (from Table 3.1.68) would result in about 5x10 l deaths,
assuming a stable world population of 6.4x10
expression period unless the period has been shown to be shorter or
9 people. It might be
more realistic to make a comparison to the natural production of
longer for a specific cancer (reference 2, par. 12, page 363).
carbon-14 and associated health risk. In particular, the two major human cancers associated with
radiation, lung and breast, are considered to elevate risk for the
125. (Page E.1, last paragraph) The bias in selection of references is duration of lifespan following exposure (Land, C.E. and Norman, J.E.,
obvious. While the last sentence quotes the NCRP and its dislike of "The Latent Periods of Radiogenic Cancers Occurring Among Japanese
linear nonthreshold risk and its use in radiation protection, to A-Bomb Survivors," Late Biological Effects of Ionizing Radiation, 1,
maintain balance the ICRP's use of risk factors as realistic estimates IAEA, Vienna, pp. 29-47, 1978; Archer, V.E., Radford, E.P., and
(see comment on Appendix C, page C.2) for radiation protection and Axelson, 0., "Radon Daughter Cancer in Man: Factors in
their use in ICRP publications 26 and 27 should also be documented. Exposure-response Relationships," Health Physics Society Annual
EPA's policy statement, 41 F.R. 28409 (1976), should also be noted. Meeting, June 1978).
126. (Page E.3, first paragraph) In the discussion of BEIR risk The dose reduction factor in the RSS report appears to be derived
estimates, emphasis is put properly on the range of uncertainty, from an analysis by Mays, et al. considering ten sets of animal data
However, it should be mentioned that the BEIR Committee did report from nine studies. If an additional two studies (that happen to show a
(reference 1, p. 168), "With this limitation in mind, the Committee reverse effect) are included in the analysis, the dose reduction factor
considers the most likely value to be approximately 3,000-4,000 cancer becomes 1.7 + 4.5 instead of the 0.22 + 0.20 reported by Mays, et al.
deaths (or a 1 percent increase in the spontaneous rate)" (emphasis As UNSCEAR 1977 points out, most of the existing animal carcinogenesis
added). data comes from observations at doses above 50 rads and that each
tumor-model system has peculiarities which prevent generalizations
127. (Page E.3, second paragraph) The paragraph considers only EPA's across multiple organ systems and cancers. See reference 53 of this
Uranium Fuel Cycle documents and states that the risk estimates there appendix for comments on the dose reduction factor in the RSS.
continue to be used by EPA. In reality EPA risk estimates have
continued to change as new data becomes available. In addition to As has been pointed out by Crump, et al. (Crump, K.S., Hoel, D.G.,
papers published by staff (e.g., Ellett, Nelson, and Mills, "Allowed Langley, C.H;, and Peto R., "Fundamental Carcinogenic Processes and
Health Risk for Plutonium and Americium Standards as Compared with Their Implications for Low Dose Risk Assessment," Cancer Res., 36,
Standards for Penetrating Radiation," pp. 587-601 in Transuranium pp. 2973-2979, 1976): "It is likely that the error in the acceptable
Nuclides in the Environment, IAEA, Vienna, 1976), various EPA reports dose associated with a simple linear extrapolation will be much less
(e.g., A Computer Code for Cohort Analysis of Increased Risks of Death, than that associated with species to species extrapolation to man from
EPA 520/4-78-012, 1978, or Proposed Guidance on Dose Limits for Persons the laboratory animal data. The BEIR Report (ref. 16) recommended
Exposed to Transuranium Elements in the General Environment, linear extrapolation on pragmatic grounds. The theoretical conclusions
EPA 520/4-77-015, 1976, etc.) show updated risk estimates and how they of the present paper are that linear extrapolation to low dose levels
were derived, is generally valid as a realistic yet slightly conservative procedure"
(emphasis added). That carcinogenesis by an external agent acts
128. (Pages E.3 and E.5, discussion of the Reactor Safety Study, additively with any ongoing process is accepted by Crump, et al. and by
WASH-1400.) EPA's dissatisfaction with the health effects estimates in Hilberg (Hilberg, A.W., "Low-Level Ionizing Radiation: A Perspective
the Reactor Safety Study (RSS) is documented in reference 53. Recent with Suggested Control Agency Options," in 10th Annual National
Conference on Radiation Control, HEW Publication (FDA) 79-8054,
pp. 386-391, 1979) in his allusion: "And, conversely because man is
living in an environment of chemical additives and pollutants, these
may set the stage for action of a very small amount of radiation
exposure."