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

55
RADIOLOGICAL ISSUES
generally valid as a realistic yet slightly conservative procedure" (emphasis added). That
carcinogenesis by an external agent acts additively with any ongoing process is accepted by
Crump, et al. and by Hilberg (Hilberg, A. W., "Low-Level Ionizing Radiation: A Perspective
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, con-
versely 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."
Most of the arguments on the RSS report centered on low dose rate, low LET radiation.
Alpha radiation dose response curves are usually characterized as both linear and dose rate
independent (BEIR 1972; UNSCEAR 1977) or as possibly providing underestimated effects at low
doses (J. Martin Brown, "Linearity versus Non-Linearity of Dose Response for Radiation Car-
cinogenesis," Health Physics, 31, pp. 231-245, 1976; V. E. Archer, E. P. Radford, and
0. Axelson; "Radon Daughter Cancer in Man: Factors in Exposure-Response Relationships,"
Health Physics Society Annual meeting, June 1978). No reports except the RSS report con-
siders a threshold curve a viable concept. (113-EPA)
Response
In this comment the EPA discusses its objections to a number of aspects of the Reactor
Safety Study (WASH-1400), as reflected on pp. E.3 and E.5 of draft Appendix E. Since the
Reactor Safety Study represents the conclusions of a respected body of scientists, many of
whom were also members of the BEIR Committee, their conclusions deserve to be considered
along with those of other experts. Appendix E does not adopt the values of WASH-1400 but
merely considers them as part of the input from which the adopted values of Table E.2 are
derived.
Draft p. E.4, Table E.1
Issue
A column in Table E.1, headed "Environmental Protection Agency," purports to be the
risk estimates used by EPA. They are actually averages for various risk models used by EPA
in reports and therefore are not directly comparable to the other risk estimates in the
table.
The estimates of 54 leukemia deaths/10 6 person-rem listed in the table were extracted
from EPA 520/9-73-003-B (Reference 4, draft Appendix E). As stated in that report
(p. A.14), the risk conversion factors are average values for absolute and relative risks
in the BEIR Report, 1972. Moreover, they apply only to the dosimetric models used in EPA
report 520/9-73-003-B.