States, there was an established practice of measuring the dose in air and we selected
the figure of 0.1 roentgen per day or about 30 roentgens per year. There was no
important difference between this and the international value other than the mode of
b. It might be noted that during the buildup of the Manhattan project and the
development of atomic energy, the guiding standard for radiation protection was that
set up by the committee and published in its third protection report in early 1936.
c. As in the case of the radiologists clearly injured by x-ray exposure, the 1930s
produced another unfortunate series of injuries--this time clearly related to exposure to
radioactive products. These were the well-known cases of the radium dial painters,
many of whom died as a result of their injuries. Some others still living are showing
signs of their injuries. A study of this situation by the advisory committee led to the
recommendation for what might be termed a permissible body burden of radium. This
was specified as 0.1 microgram (or microcurie) of radium. This value also formed an
important baseline for the Manhattan project and atomic energy operations.
d. Following this selection of a permissible body burden for radium, a
continuous and painstaking series of studies of the subject has been carried out ever
since the 1930s and has involved every person known to have been exposed to radium
or its products in any form. All of these studies have shown the almost unbelievable
fact that the value selected in 1941 is just as valid today as it was believed to be then.
In the whole history of radium exposures, no one has been found with neoplastic injury
related to a body burden of less than 0.1 microcurie of radium. Even more astonishing
is that beginning at about 0.2 of a microgram and on up, there is increasing evidence of
2-9. ADVENT OF ATOMIC ENERGY
a. The mid 1940s marked the beginning of a whole new era, namely the
development of atomic energy and the production of large quantities of artificial
radioactivity. Quite aside from weapons, the normal research in atomic energy
produced various kinds and quantities of radiation, presenting problems that in the
1930s were almost unimaginable.
b. There is another factor of importance here. Because of the existence of
controlled atomic energy, radioactivity was brought to public attention through its
military use during the war. The unprecedented speed in the development of nuclear
energy and its probable impact on the future of warfare had a tremendous effect on a
completely unprepared public. In fact, one could almost say that until this event, the
ordinary citizen had been passively unaware of ionizing radiation except as it may have
been encountered by an occasional patient.