All volunteers participating in the Marshall Islands Radiological Surveillance Program are
issued a preliminary copy of their dose report immediately after receiving a
whole body count.
Scientists from the Lawrence Livermore National Laboratory verify the measurement data and, if required,
issue a revised dose report. Individual whole body counter or plutonium bioassay measurement data that
yield statistical significant
in excess of 10 mrem will normally evoke some type of pre-determined action or investigation (refer discussion outline below).
These actions will nearly always lead to follow-up verfication measurements but may also include a dietary evaluation and/or
a work history review. Below this level,
for assigning doses (Daniels et al., 2007) are assumed to be valid and no further action is taken.
Data may be withheld from the website and hard copy reports while these investigations are on-going.
The Lawrence Livermore National Laboratory Marshall Islands Program action level is one-tenth of the
investigation level used throughout the U.S. Department of Energy and two-thirds of the U.S. Environmental
Protection Agency guideline for cleanup of radioactively contaminated sites. In addition, at the end
of each calendar year, all program volunteers receive a former written report containing an estimate
of their 'calendar year dose' based on all available verified data for the year. Program volunteers
are also invited to discuss their concerns with local technicians and/or to contact
Dr. Terry Hamilton at Lawrence Livermore National Laboratory for more information.
Due to the very conservative nature of our dose methodology and preference not to trivialize
doses no matter what the level, we anticipate that the default assumptions for calculating
committed doses from low-level plutonium bioassay measurements will occasionally yield values
that exceed the 10 mrem investigation level. In some cases, doses in excess of 10 mrem will
not necessarily evoke a follow-up response. The reasoning for this is that the low-level
plutonium bioassay measurements usually contain a relatively large uncertainty where the
confidence interval (nominally tested at 3 × measurement MDA) spans the investigation
action level. As such, dose estimates are computed for all the measurement data but the
scope of any follow-up action may be limited to those sample analyses that are clearly
distinguishable from the measurement MDA (e.g., 3 × MDA) or upon receiving specific
requests from concerned individuals.