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Radioactive :-Food Chains in Arctic Regions
Jorma K.Miettinen
Department of Radiochemistry
University of Helsinki
Investigations of bioenvironmental radioactivity in the arctic regions
of Scandinavia and Alaska have revealed high body contents of 705, and os
in animals and man. Large quantities of these radionuclides have been produced
and spread into the stratosphere by the megaton-range weapon tests. Being
"third generation” - fission products these nuclides are "born" from their
gaseous parent nuclides mainly in the stratosphere after the fireball has
spread and cooled and thus appear in a very finely divided, nearly monoatomic
state. This fine dust comes down primarily by so-called stratospheric cold air
injections, which are stronsest in spring, in April and May, and between 30°
and 60° northern latitude.
Air currents from the west usually take the fallout to Lapland after it
has got into the troposhere somewhere above the North Atlantic, often within
the so-called Icelandic low-pressure area. The bulk of it comes down with rain
above the Norwegian mountains. Fallout as weil as the amount of rain is much
smaller in Sweden and Finland than in the mountainous parts of Norway, and
about the same or siightly lower in Lapland than in the southern parts of the
countries (Fig.1}). In the whole of Finland the fallout is in general about
1/3 to 1/2 of that in the middle Europe, e.g. Berlin-Dahlem Li/. The integrated amount of ‘3os was about 20 ns/in” in Swedish soil in 1960 {2}. Thus,
L27 Cs in animals and people . in Lapland are not
the high activities of 25, and
caused by exceptionally large amounts of fallout, but rather by unusual food
chains.
For the elucidation of the arctic food chains, a Finnisn Atomic Energy
Commission-sponsored field investigation called “Projeet Lapland" was started