Scientists and doctors have compiled radiation dose estimates into a database -- called Operation Tomodachi Registry -- that eventually will list the 70,000 U.S. service personnel, civilians and family members on or near mainland Japan during the 60 days after the March 11, 2011 earthquake and tsunami, Stars and Stripes reported Wednesday.
The highest radiation dose estimates were on bases in Sendai, about 50 miles from the nuclear power plant, military officials said. where adults may have received doses of up to 0.12 rem of radiation to their bodies and 1.2 rem in their thyroids. Doses at other bases generally were lower than at Sendai.
Stars and Stripes said a CT scan results in a full-body dose of 5.0 rem, while an average annual dose from environmental radiation in the United States is about 0.31 rem. U.S. exposure guidelines indicated accepted safe limits for radiation doses to the thyroid are 50 rem for adults and 5.0 rem for children.
Officials said when the database is completed in December, it will include location-based dose estimates at 13 locations in Japan.
Officials decided to publish the information because the Defense Department wants to ensure a registry was available "within the lifetime of the individuals" to address disease- or illness-related issues that could possibly be tracked to radiation exposure, said Craig Postlewaite, a Pentagon public health practitioner.
"If people develop health conditions in the future that their providers feel might be related to radiation they can go to the registry," Postlewaite said. "If we didn't have this information available there would be questions in people's minds."