U.S. researchers said Wednesday they have developed a novel blood test that could predict whether radiation exposure in a nuclear accident like Japan's Fukushima disaster will eventually be fatal within the first 24 hours.

Using such a test could "facilitate timely medical intervention and improve overall survival of exposed individuals," according to their paper, which was published in the U.S. journal Science Translational Medicine.

Exposure to high-energy radiation from nuclear power plants, radioactive material, nuclear weapons, and other sources can damage different organs and lead to cancer and infection.

Injury from radiation, however, can take weeks or months to appear, and existing techniques do not effectively predict the severity of injury sustained, they said.

"After a radiation release, there is currently no way to tell who was exposed and who wasn't, and if someone was exposed, is it lethal or not?" senior author Dipanjan Chowdhury of Boston-based Dana-Farber Cancer Institute said in a statement.

Drugs that can limit bone marrow damage are available but, to be effective, must be given before the appearance of radiation symptoms, Chowdhury noted.

In their study, the researchers focused on microRNAs, small RNAs that help regulate gene activity. These molecules are made in cells, but some are found in the bloodstream, and the researchers asked whether varying doses of radiation might cause corresponding changes in microRNAs in the blood.