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4.
In 1979, seawater did not contain measurable amounts of plutonium from
the accident, except in particles just above the seabed at the point
of impact.
5.
In the most recent environmental survey completed in 1979, plutonium
from the accident was not detected in any of the higher animals
(birds, fish, mammals) with any certainty.
The contamination has been
confined to the sediment and those organisms that live in or on the
sediment.
The only direct link between the Greenlanders and the portion of the foodchain
with detectable plutonium contamination {fs through the mussels (bivalves).
In
1974, the average concentration of plutonium in the soft parts of the mussels
found within a radius of 20 km of the crash site was about 20 pCi/kg.
If we
asume that a Greenlander eats 100 grams of mussels a day from this region for
70 years, the estimated annual dose rate to the bone at the end of 70 years
would be .075 mrad (from EPA 520/-77-016, Table A3-6).
Even with this
extremely conservative scenario, the projected maximum annual dose rate is
less than 3% of the proposed EPA limit.
I was unable to find any cost estimates for the clean up operation at Thule.
It involved the resources and people of many organizations and would be
difficult to reconstruct.
However, since the clean up operations apparently
were sufficient to meet the requirements for limiting exposures to individuals
as currently proposed by the EPA, it is my opinion that the clean up costs
wouldn't be appreciably different today than they were then, save the
adjustment for inflation.