Researchers Bill Robison and Terry Hamilton of the Lawrence Livermore National Laboratory calculated the radiation doses for people possibly returning to Bikini, Enjebi and Rongelap Islands and found some could have lower radioactive levels than the average background dose for residents in the United States and Europe.
Robison and Hamilton determined that when it rains, a portion of the soluble cesium-137 -- an isotope of cesium -- is transported to groundwater that lies about 10-feet below the soil surface. The groundwater eventually becomes mixed with ocean water so the cesium is lost from the soil.
In addition, Robison said they found potassium treatment and removal of the top 6 inches of soil around houses prior to construction of new buildings to reduce external exposure could be used as a remediation strategy before resettlement.
"If this approach is taken, the natural background dose plus the nuclear-test-related dose at Bikini, Enjebi and Rongelap would be less than the usual background dose in the United States and Europe," Hamilton said.
The United States conducted 24 nuclear tests at Bikini Atoll, including the 15-megaton test that was the primary source of radioactive contamination of Bikini Island and Rongelap and Utrok Atolls.
The research appears as the cover article in the journal Health Physics.
Copyright 2010 United Press International, Inc. (UPI).