Almost anyone diagnosed with thyroid cancer who was a child in the United States during open-air nuclear testing at the Nevada Test Site, and drank fresh milk from stores or farms, could make a case that development of the disease likely was influenced by radioactive fallout.
That's the belief of F. Owen Hoffman, one of the authors of a new report summarizing impacts of fallout on thyroid cancer. The report is "Thyroid Doses and Risk of Thyroid Cancer from Exposure to I-131 from the Nevada Test Site," prepared by SENES Oak Ridge Inc., consultants based in Oak Ridge, Tenn.
It calculates risks, breaking out several areas throughout the country and analyzing the danger of thyroid cancer to people born in certain years.
Federal fallout compensation is available only to people who lived in selected counties. But as documented years ago, fallout from open-air nuclear blasts at the test site fell throughout the country.
The National Institutes of Health has set up a fallout risk calculator on the Internet, which is useful for figuring exposure and risk. The program asks those using it for facts such as age, gender and residency.
SENES' study makes some of the same calculations for several groups of citizens, with birth year, gender and location playing important roles. It calculates risks based on these factors and shows estimates about exposure.
The new report's risk calculator is updated in a way that is similar to an improvement the NIH plans for its online site, according to the study.
"Virtually all 160 million Americans who lived in the continental U.S. during the nuclear testing period were exposed to I-131," the report says.
Radioactive Iodine 131 would churn into the air with a blast's fireball. It would travel in clouds and drop as fallout. Cattle eating contaminated grass would pass along I-131 in their milk, and the material tended to accumulate in thyroid glands of people who drank milk.
The federal government has laws governing compensation to atomic workers who were exposed to radiation and developed cancer.
For compensation, there must be at least a 1 percent chance that the baseline risk of thyroid cancer has doubled for the atomic worker, Hoffman, president and director of SENES, said when contacted by the Deseret Morning News. The baseline represents the risk to unexposed people of the same age, gender and other attributes.
Almost anyone in the United States who was "unfortunate enough to have been diagnosed with thyroid cancer, a fairly rare disease, would qualify (for compensation) regardless of location of residence throughout the 3,090 counties of the USA," Hoffman said in an e-mail response.
That is, they would qualify only if:
The laws for exposed workers were to apply to members of the public exposed off-site, which they don't.
Fallout exposures mostly occurred when the person was a child.
And "during the time of atmospheric weapons testing, the individual consumed fresh sources of store-bought or farm-produced milk."
"The look-up tables (in the report) contain estimates of doses and risks for eight representative birth cohorts and 67 locations in eight regions around the continental United States," the new publication says.
The Radiation Exposure Compensation Act of 1990 (amended in 2002) does not cover many millions of Americans exposed to fallout during the period of open-air nuclear testing at the Nevada Test Site. It provides money for some specialized workers such as uranium mine ore haulers, plus affected civilians who lived in 10 counties of southern and other parts of Nevada and Arizona.
But the report makes clear that the radioactive Iodine 131 from atomic tests was carried in fallout that hit throughout the country, making its way into milk sold commercially. Usually fallout happened during rainfall, but sometimes it hit without precipitation.
Some of the hardest-hit areas were both southern and northern Utah, and parts of Montana, Kansas, Colorado, Vermont, South Dakota, Idaho, Iowa and other areas.
For a woman born in Salt Lake City in 1952 who has lived in the area to the present, who has consumed retail commercial milk and who has never had thyroid cancer, the chance of coming down with that disease is about 6.6 out of 1,000. (That is a mean, with the lowest figure 1.2 and the highest 28.)
If she had lived in an area that was not peppered by fallout, her chance of coming down with thyroid cancer would be 1.8 per 1,000.
Fallout in Salt Lake City increased the risk of thyroid cancer for a woman born that year by 3.7 times, compared with the risk from natural sources. Men's chances of exposure were lower because male babies are not as susceptible to ill effects of the radioactive iodine that worked its way into milk during the era of open-air testing.
Of groups whose risks were calculated, the highest mean estimate was for women born in Gunnison, Colo., in 1952. Risk of such a woman developing thyroid cancer was calculated at a mean of 18 out of 1,000, or 10 times as likely to develop the rare disease as someone not exposed who was born that year.
However, it would be hard to find an American born during the period of open-air testing at the National Test Site — early 1951 through the middle of 1962 — who wasn't exposed as a baby.
Radiation doses to the thyroid gland and the risk of developing thyroid cancer depended on age at the time of each nuclear test, location and type and amount of milk consumed. Milk from goats posed a greater danger, which could have implications for Navajos who drank goat's milk.
Breast milk was safer than cow's milk available commercially, the report adds.
Support for the SENES project came in the form of a grant from the Citizens' Monitoring and Technical Assessment Fund, according to the report's cover. Its authors are Ann G. Moore, A. Iulian Apostoaei, Brian A. Thomas and Hoffman.
E-mail: bau@desnews.com