By Lee Davidson
Deseret News Washington correspondent

      WASHINGTON — Despite 14 years of work on a draft study about the cancer dangers downwind of fallout from atomic bomb tests, federal scientists should again reanalyze their data about radioactive iodine-131.
      The National Research Council concluded that Tuesday after evaluating a draft 1997 study by the National Cancer Institute about fallout from the tests.
      That draft study took 14 years of work and has yet to be published in final form. It had said that fallout from the tests hit every county in America but posed relatively minor elevated risk of cancer.
      The council concluded Tuesday that the original study generally did a good job of estimating radiation exposure and risks nationwide, guessing that the tests likely caused cancer in only 11,000 people downwind, but said it had some weaknesses.
      That includes, it said, the need to reanalyze its data about the spread of iodine-131 to correct some acknowledged errors in measurements, lessons learned about the spread and toxicity of iodine-131 from the Chernobyl disaster, and how the contribution of global fallout on top of U.S. fallout might increase cancer dangers.
      Still, the council says it guesses that additional work likely won't change estimates much about how many people developed cancer from the tests.
      "The recommended reanalysis of iodine-131 exposure is unlikely to make large changes in the key results, but it will make the risk estimates current, and hence more credible," said William J. Schull, chairman of the NRC committee that wrote the report.
      On top of that, the research council rejected the calls from some to expand the federal research to look more closely at other, heavier radioactive particles in fallout.
      Iodine-131 is relatively light and could travel for hundreds of miles or more before falling out of radiation clouds, which is why it spread nationwide. Residents of southern Utah close to the Nevada Test Site have long claimed they were at more risk for cancer because of heavier radionuclides that fall out much more quickly.
      But Schull said, "Apart from iodine-131, the draft report indicates that the health risk associated with other radionuclides released in weapons testing is small, so developing more precise estimates of radiation dose and cancer risk will probably be of little added value."
      That upsets some downwinder organizations.
      "To say they should not bother with heavier radionuclides is criminal," said Janet Gordon, a Cedar City resident who is co-chairwoman of the National Committee for Radiation Victims. She lost many family and friends to cancer she blames on the tests.
      "We've seen the government constantly downplay risks from the tests" she said.
      The original study by the National Cancer Institute was ordered by Congress in 1982 after Deseret News stories showed that fallout had spread nationwide and showed higher-than-expected cancer rates in areas immediately downwind of the tests.
      When data from that study was first released partially in 1997, it estimated that 10,000 to 75,000 people nationwide might develop thyroid cancer from exposure to iodine-131 released in the tests.
      That study used complicated procedures to compute likely doses based on where people lived, where fallout blew after each of 90 atomic tests, people's age and how much milk they likely drank, and the source of that milk.
      Iodine-131 is most easily absorbed in humans by drinking milk contaminated when cows ate feed contaminated by fallout. Children and people who drank more milk had higher doses. People who drank milk from a family cow had higher doses than those who drank processed milk.
      Original data released in 1997 illustrated that with a hypothetical family living in Salt Lake City in the 1950s. It said the father would have absorbed 1.3 rads of radiation, and the mother 1.4. But a baby born in October 1951 would have absorbed a relatively large 10 rads because it was drinking more milk during some of the worst tests.
      A second child born in September 1952 would have had only 8.9 rads because of the timing of tests. A third child born in 1956 would have had 5.5 rads. And a child born in 1958 would have had only 0.1 rads as the tests neared an end.
      The research council urged that the 1997 study finally be published promptly and the reanalysis of iodine-131 should follow.
      Of note, Congress created a program in 1990 to compensate some victims of some types of cancer. It is limited to a few counties in southern Utah and Nevada and Arizona. Some in Congress had called for expansion of that program based on the 1997 results that showed radiation from the tests spread nationwide.
     

E-MAIL: lee@desnews.com