Several University of Utah researchers wrote the new report, which will appear in the November issue of the journal Epidemiology. The paper corrects problems with a 1993 study.

Earlier studies indicated that young children living downwind from nuclear tests in parts of Utah and Nevada were thought to be 3.4 times more likely to develop thyroid neoplasms, which are precursors to thyroid cancer. The new study revised that estimate to 7.5 times more likely, said Joseph Lyon, a U. family and preventive medicine researcher and study author.

Children living in Utah and Nevada during above ground weapons testing were exposed to radioactive iodine after fallout landed on pastureland. Grazing dairy cattle ate the contaminated grass, which put radioactive material in the resulting milk.

Children who drank this milk absorbed the radioactive material in their thyroids. Such exposure can lead to thyroid disease as well as cancer later in life.

"We went back and cleaned up a lot of the problems that were inherent in the data," Lyon said.

Some of the problems were rooted in bugs in earlier computer programs. Once the programs were fixed, researchers felt they had more accurate estimates of radiation doses for children of that era, said Stephen Alder, another study author at the U.

"This paper is the improved dose estimation for individuals," he said.

Alder explained that these results are not meant to alarm people who lived downwind of the test sites, but to encourage such people to watch for certain potential health problems.

Lyon said the study suggests a relationship between fallout and thyroiditis, a more common thyroid disease. Children who grew up downwind appear 2.7 times more likely to develop thyroiditis, up from 1.1 times as likely as determined in the previous study.

The study looked at data collected on 2,497 people from in 1985 and 1986. The new study did not provide any estimates of how many people may have developed thyroid neoplasms or thyroiditis due to fallout exposure. Lyon said there is no funding left to perform such an analysis.

Lyon had been working on an $8 million partnership with the U.S. Centers for Disease Control and Prevention to study the long-term health effects of fallout exposure. Researchers had done follow-up testing on 1,700 people, but fell short of the 3,500 goal after funding was cut.

glavine@sltrib.com