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Thyroid disease linked to radiation

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Federal scientists have uncovered a link between radiation exposure from a nuclear weapons plant and autoimmune disease.

By extension, it is another indication of the dangers of the open-air atomic testing that rained fallout on Utah and throughout the United States.

The Hanford Birth Cohort study was released last week by the Agency for Toxic Substances and Disease Registry. It examined residents who lived for at least one year near the Hanford Nuclear Reservation between 1944 and 1957, when the plant was releasing radioactive gas while manufacturing plutonium for bombs. Their health reports were compared with those of a similar number who lived in other areas of Washington.

The study tallied conditions of 1,160 people in both areas. To be counted as among those in the more heavily exposed area, people had to have lived in Adams, Benton or Franklin counties, Wash., or at least one year between Jan. 1, 1945, and Dec. 31, 1951.

The control group included residents living in Mason, San Juan or Whatcom counties.

"The study found a small increased risk of Hashimoto's thyroiditis . . . for men who lived closer to (the) Hanford facility," says a report posted on the Internet at www.atsdr.cdc.gov/hanford/docs/New%20Hanford.pdf.

Hashimoto's thyroiditis is an autoimmune disease caused by the thyroid gland producing too little thyroid hormone, it adds. Oddly, the percentage of women with the disorder was the same among both groups, indicating that this exposure affected only men.

The report offers this explanation for the exposure: "The Hanford nuclear facility released large amounts of iodine-131 and other radioactive materials into the air from 1944 to 1957. Iodine-131 (radioactive iodine) was carried by winds and deposited on vegetation. Cows and goats ate the vegetation contaminated by iodine-131. Iodine-131 passed into the cow's and goat's milk that people drank."

The bulk of the exposure for those affected came through this source, it adds, but people also were exposed by eating contaminated fruits and vegetables and by breathing air with the radioactive material in it.

"Once inhaled or ingested, iodine-131 is deposited in the thyroid gland. Children who lived in Adams, Benton or Franklin counties at the time of the releases received the highest doses of iodine-131."

The study found no evidence for an increased rate of diseases like rheumatic fever, stroke, fibromyalgia or heart attacks.

The study found that 10 men among the 291 checked in the high-exposure counties had the autoimmune thyroid condition, compared with four men among 385 checked in the control group. That was 3.4 percent of men in the high-exposure counties compared to just slightly over 1 percent in the nonexposed counties.

Men in the exposed counties were 3.31 times as likely as men in the more distant counties to have the disorder, the report notes. It labeled this finding "statistically significant" and advised people who think they may have been exposed to see their physicians.

The study has many gaps, including its apparent ignoring of cancer. It also does not attempt to refine the risk to someone who lived throughout the entire period in the high-exposure counties, compared with those who lived there just a year. Finally, exposed children were the most vulnerable, it says, but does not state how many of those studied were adults while living in the high-exposure counties.

This is a "red flag" warning, said Dr. Peter Rickards, a Twin Falls, Idaho, podiatrist who was involved in a federal study concerning the Idaho National Engineering Laboratory.

"It is interesting that they did find actually triple the rate" for autoimmune thyroiditis among men, he said.

"This is really important. I'm not sure I believe at all that the women did not reflect the higher autoimmune (disease) rate," he said.

Rickards is calling for the federal government to give documented downwinders, both in Utah and Washington, $500 vouchers for medical exams.

This would be a "very inexpensive, efficient way to track the actual documented downwinders," he said.

Rickards warned that the study might turn out to be "just the tip of the iceberg" of autoimmune disorders among those exposed to radiation.

This was the latest in a series of studies linking health effects to radiation involving nuclear bombs. Iodine-131 from above-ground tests at the Nevada Test Site has been tied to cancer.

A Centers for Disease Control and Prevention advisory on the Internet points out: "People exposed to I-131, especially during childhood, may have an increased risk of thyroid disease, including thyroid cancer many years later. Thyroid cancer is uncommon and is usually curable."

E-mail: bau@desnews.com