wniformily on an infinite plane secording to the proesdis of
G. M. Dumming (5).
Absorption and build-up factors have been Included
for each isotope, and the resulting does rates area shown in Tabie ITT.
It should be empaesiccd thai these dosy sates in im ‘gOfhour axe Tor
an unshisided point one moter above the eround.
The doses thus calculated wors compared with the dcse measured
with an approvriete ionization shamber e) various times axing 1939,
In order to compare calculated end empirical dose
rates one must beer
in mind thet the measured doze contains a component dus to natoral
radioactivity and to cosmie rediation. ‘The dose from U, Th, end x9
ney be calevlated from Tnitavist’s equations using the concentrations
of these radicelenents determined from sauaneray spectrometry (9).
The dose from cosmic radiation yas taken from the literatere end
expressed in prad/ncur. Table TTI shows the caleuleted dose for
April 1959, totaling 19.2 pred/hour, eontrasted with a moasured doze
rate of 18.5 prad/hour.
Agreement of a similar order was observed
during the succeeding spring and summer months, lending support to
both the method of calculation and to the method of measuring Pission
product concentration.
4s previously stated, these dose rates certain to the unshielded
situation.
The sctual dose to which an individual is exposed mat
take into atcount shielding, tine spent cuteofdoors, and the like.
Agein use was mado of en ionization chamber to determine the dose rate
indoora snd outside.
Within the sccurecy of measurement, a shielding
factor of 5 was found for fallout rediation (4.8. the dose due to
meet
op
BRT ee
mu. 4 ue