aa
[6/ The maximum value, 790 nc, was exactly the same as in Inari. Thus, the
situation seems to be very similar in Alaska and Lapland.
Although the highly efficient food chain lichen-reindeer-man probably is
(
the most important one in Lapland, it is not the only one. Efficient hydrospheric
food chains evidently prevail in the fresh waters, as high activities in the fish
of pray have been found in Lapland in the last few years /2T/s In summer 1903
pike and perch contained in Lapland 10 to 15 ne Ios/eg fresh weight, twice the
summer-value of this nuclide in reindeer meat. Hignest values have been obtained
in fish from lakes with a high humus but low cation concentration . Nearly as
high Hos contents as in Lapland have been found in fish from similar type of
lakes in southern Scandinavia /27 328,29_/ while about ten times lower avlues have
been found in fish from lakes of the "rich" types [29/. The factors causing
these great differances in Finnish lakes are not yet known in detail.
Other interesting food chains involve the radon daughters rad(“1pp,
half life 19.4 y.) and raF(“*° po, half life 140 d.). Radium-226 is always present
in the soil from where its daughter, radon-222, diffuses into the ground level
air, From there the radon daughters are brought back to the soil surface by rain
or aerosols as "natural fallout" and are absorbed by lichen and pass further to
reindeer and man. Reindeer meat and bone have exceptionally high contens of RaD
and RaF, meat about 0.2 pe /x00/; bone about 5-LO pc/s dry wt. of each
/30,31/. Beef contains only about 0.01 pe/g ary wt. RaD {32/. On the basis
of known facts about RaD resorption in man {32/ and reindeer meat consumption
by Lapps £39/s Lapps” RaD content can be estimated to be about 10 times higher
than the Northern Hemisphere average.
bones have not been analysed yet but
for one single Eskimo bone 2.3 pe/g ash /33B/; a value about 15 times the
American average /32/s was reported. Assuming for Lapps a ten times higher
RaD+RaF body content than the general population average, the effective dose to
their skeleton from these two nuclides alone may be estimated to be of the order
of 120 mrem/y. (based on facts in refs 32 and 34).
The present results of our "Project Lapland and the corresponding studies
in Sweden and Alaska can be summerised in the following way:
1) They have given interesting information about terrestrial and hydrospheric food chains of fission product nuclides,
information which is also applie-
able to the environmental problems of peaceful atomic energy power programs:
2) they have given precise information about the present radiation dose to
Lapps and Eskimos from internal: contamination by articifial radionuclides, and