Thyroid disease linked to radiation

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.