Resuspension studies in the Marshall Islands

Area of Science:

• Environmental Science
• Radiological Health
• Atmospheric Chemistry

Background:

• Residents of the Marshall Islands face potential long-term inhalation exposure to plutonium.
• Understanding plutonium redistribution and personal exposure mechanisms is crucial for risk assessment.

Purpose of the Study:

• To assess the contribution of inhalation exposure to the total dose for Marshall Islands residents.
• To investigate plutonium-contaminated dust aerosols and their resuspension dynamics.
• To determine individual exposure levels in various environmental and occupational settings.

Main Methods:

• Monitoring inhalation exposure on Bikini and Enewetak Atolls.
• Characterizing plutonium in soil-borne aerosols versus sea spray and organic aerosols.
• Measuring plutonium resuspension rates using the meteorological flux-gradient method on bare and stabilized soil.
• Conducting personal air sampling in simulated occupational environments and during traffic exposure.

Main Results:

• Enhancement factors (plutonium in aerosols vs. soil) were below 1 in vegetated areas (0.4-0.7).
• Enhancement factors exceeded 1 (up to 3) in disturbed bare soil, roadside travel, and occupational settings.
• Plutonium resuspension is significantly higher from disturbed surfaces and during specific activities.

Conclusions:

• Soil disturbance and specific activities like traffic and occupational duties greatly increase plutonium inhalation exposure risk.
• The study provides key parameters for assessing long-term inhalation exposure to plutonium aerosols.
• Findings highlight the importance of managing soil conditions to mitigate radiological risks in affected areas.