Re: Children may get too much radiation in CT scan

["dkosloff1" <dkosloff1@email.msn.com>]

Here is the origin of the risk estimate, with references.  The references
all appear to be advisory bodies, with no regulatory bodies represented.

"Estimated Risks of Radiation-Induced Fatal Cancer from Pediatric CT"

"The linear extrapolation without a dose threshold that is used to
extrapolate cancer risks to very low doses has been the subject of much
debate [37,38,39,40]; however, the main regulatory and advisory groups that
have reported on this issue [12, 13, 41, 42] have all concluded that the
most scientifically credible approach to risk extrapolation to this dose
range is a linear extrapolation from greater doses, which is the assumption
implicitly adopted here."

References
12.  BEIR V (Committee on the Biological Effects of Ionizing Radiations).
Health effects of exposure to low levels of ionizing radiation. Washington,
DC: National Academy Press, 1990

13.  International Commission on Radiological Protection. 1990
recommendations of the International Commission on Radiological Protection.
Oxford, England: Pergamon, 1991. ICRP publication 60

37.  Strom DJ, Cameron JR, Cohen BL. The LNT model is appropriate for the
estimation of risk from low-level (less than 100 mSv/year) radiation, and
low levels of radon in homes should be considered harmful to health. Med
Phys 1998;25:273 -278[Medline]

38.  Tubiana M. Radiation risks in perspective: radiation-induced cancer
among cancer risks. Radiat Environ Biophys 2000;39:3 -16[Medline]

39.  Heidenreich WF, Paretzke HG, Jacob P. No evidence for increased tumor
rates below 200 mSv in the atomic bomb survivors data. Radiat Environ
Biophys 1997;36:205 -207[Medline]

40.  Pierce DA, Preston DL. On: `No evidence for increased tumor rates below
200 mSv in the atomic bomb survivors' data.' (commentary) Radiat Environ
Biophys 1997;36:209 -210[Medline]

41.  UNSCEAR (United Nations Scientific Committee on the Effects of Atomic
Radiation). Sources and effects of ionizing radiation. New York: United
Nations, 1994. UN publication E.94.IX.11

42.  National Council on Radiation Protection and Measurements. Evaluation
of the linear non-threshold dose-response model. Bethesda, MD: NCRP
Publications, 2000 (in press)

Don Kosloff dkosloff1@msn.com
2910 Main St. Perry OH 44081


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