Health > Protective measures against dangers resulting from the use of radium, roentgen and ultra-violet rays

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of Ba each, are stored together, the reach is, of course, proportionately extended, so
that, in an unfavourable direction, it is 90 cm. for 200 mg., and so on.
A separate room is to be provided for the “ make up ” of applicators. Lead screens
of not less than 1 inch thickness are to be used (see above), and proximity to the
radium is only to occur during actual work and for as short a time as possible. The
measuring room is to be a separate room and should contain the radium only during
its actual measurement. Assistants are not to remain in the same room as patients
undergoing radium treatment. The persons engaged in “ making up ” applicators are
not to be engaged on such work for periods exceeding six months.
Similar regulations will be necessary for institutes in which radium preparations
are put up in containers, radio-active luminous paints are prepared, etc.
For the despatch of radium preparations by post regulations have also been laid
down in the international provisions. It is stated that in the case of small quantities
the container should be lined throughout with lead not less than 3 mm. thick and that
it is more satisfactory to transport large quantities by hand in a suitably designed
carrying-case.
In my opinion, 3 mm. of lead protection will serve no very useful purpose, since it
attenuates gamma rays by 20 per cent at the outside. Better results would be secured
if the preparations were placed, not only in a lead container of a thickness to be graduated
according to the radium contained, but in the middle of fairly bulky packing so that
a certain factor of distance would be introduced. In addition to that, a declaration of
contents should be required, since it must be borne in mind that, apart from considera¬
tions of protection for the post office staff, other packages which may happen to be
brought into proximity with radio-active substances are liable to be damaged thereby,
e.g., photographic plates.
Precautionary regulations are especially necessary in connection with the use of
emanation, since the gaseous emanation, on breaking down, leaves a radio-active deposit
which may gradually exert destructive effects, on the skin for instance ; the inhalation
of large quantities is injurious, and premises, measuring instruments, etc., may he
“ infected ” by emanation. The international provisions, therefore, specify that the
radium solution should be stored in lead containers of the previously specified thick¬
ness in a special room which should only be connected with the pumping-room by a
tube. Rooms should be ventilated with an exhaust fan, and rubber gloves should be
worn.
So far as the protection of adjacent rooms is concerned, it can only be adequate in
this case, as distinct from that of X-rays of normal hardness, if the twofold precaution
is taken of maintaining an adequate distance from the source of radiation and of casing
the latter in lead. Owing to the low lead equivalence of masonry, protection by the
latter is hardly worth considering. Particulars of the distances that must he maintained
in order to keep adjacent rooms free from injurious radiation will, again, be obtained
from Graph IV.
8. Protective Measures in the Case of Other Kinds of Radiation.
Protection is also necessary against the beta rays of radio-active substances. The
beta rays are endowed with considerable kinetic energy; their power of penetration
is consequently small; and this is the reason why they are only able to produce very
superficial, though very extensive, effects, on the human skin for instance. Owing to
their low power of penetration, protection is comparatively easy to provide. We are
only concerned, here, with very slightly filtered radio-active preparations, and with
the naked glass capillary tubes loaded with emanation. The best form of protection,