Field programs were initiated at both Enewetak and Bikini Atolls to
specifically develop the data required to produce more precise radiological
dose assessments and to define how the ecosystems operate.
Major subsistence
crops have been planted to determine the radionuclide concentration in the
edible foods, define the time dependence of radionuclides in the atoll]
ecosystem, and deve lop concentration ratios (plant/soil) for predictive dose
models. Additional research is designed to delineate the cycling of
radionuclides to better understand the transport of elements in the atoll
ecosystem and to evaluate potential remedial measures for reducing the uptake
of critical radionuclides in the subsistence crops.
Soil samples are analyzed
as part of this program not only to develop concentration ratios but also to
supply the necessary data to evaluate the inhalation pathway.
Usable
groundwater sites are identified and the radionuclide concentrations are
carefully assessed since this water may be used in the future for drinking,
household or agricultural purposes.
In the marine environment fish, water and sediment samples are collected
to determine the concentration of radionuclides for use in the dose
assessments; in addition, the data are also used to develop predictive models
for the marine pathway for remobilization of radionuclides from the sediment,
lagoon flushing rates, concentration ratios for fish and water, temporal
variations of radionuclides in lagoon water, etc.
One of the critical variables in any Marshal? Island dose assessment is
the assumed dietary intake for the population.
Published data on the average
annual intake of locally grown foods is very sparse.
The estimated dose is
directly proportional to the intake of local food products grown on the
atolls.
It has, therefore, been essential to attempt to develop information
on the dietary habits of the residents of the various atolls; these studies
have been very limited to date and need to be included as a major effort under
P.L. 96-205.
1]