g. The 1949 report was written primarily for the protection of radiation workers
both in industry and medicine; but also being more general, it introduced the concept of
a lower level for nonoccupational exposure that was set at 1/10 of that for radiation
workers. This was in part because of the recognized greater sensitivity of young
persons and, even more so, of the fetus. At the same time, it recommended the same
level of exposure for the population as a whole. It was further recommended that for
the population, the total exposures be averaged over a period of one year. This was in
tacit recognition of the fact that, for such low levels of exposure, it probably did not
make any difference whether they were received all at once or spread uniformly over a
long period of time. Conservatively speaking, this concept is correct.
h. Thus, fetal sensitivity was recognized and special warnings given about
exposure of the fetus or of women during childbearing stages. So also were the
genetic effects of radiation recognized, but at that time, in a fairly qualitative way.
(Herman Muller, who had long been concerned about the possible genetic effects of
radiation, was a member of the committee.)
i. The possibility of lifespan-shortening due to radiation exposure was
recognized. This was believed to be nonspecific and demonstrable only by statistical
means.
j. The report included discussions of the long-term effects of radiation and the
mechanisms of recovery and nonrecovery from exposure and it dealt very clearly with
the lack of information on the effects of very low doses of radiation. It was the
philosophy in this report that has led to the conservative assumptions regarding the
linear nonthreshold relationships between dose and effect, which, if interpreted literally
and carried to the extreme, could unduly restrict radiation use. It was this situation
which led the committee to adopt the general concept that any radiation exposure might
involve some risk, however small. It further recognized that the setting of protection
standards would have to involve value judgments in comparing the risks and the
benefits that would somehow offset them.
k. This risk-benefit or, better, risk-cost concept is one of critical importance to
the evaluation of the whole radiation protection problem.
2-11. RADIATION PROTECTION GUIDANCE
Several international and national organizations provide guidance in matters of
radiation protection. These organizations are not official agencies of the Government;
however, their recommendations are often adopted by Federal, state, and local
regulatory bodies.
a. International Commission on Radiological Protection (ICRP). The ICRP
(established in 1928) formulates basic radiation protection philosophy. Originally
concerned chiefly with medical x-ray protection, the ICRP has expanded its scope to
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