Thyroid disease risk greater near Hanford
RICHLAND – Men who grew up near the Hanford Nuclear Reservation in south-central Washington during the 1940s and 1950s have a slightly higher risk of developing thyroid disease, according to a new federal study.
The results of the study may provide the strongest potential link to date between radioactive emissions from Hanford and disease in people who lived downwind of the plant.
About 2,000 people have filed suit against the federal government, claiming that radioactive releases from Hanford damaged their health.
The federal government created Hanford in the 1940s as part of the top-secret Manhattan Project to build the atomic bomb. During the process, radioactive iodine was released to drift with the wind, contaminating produce and grass that milk cows ate.
Radioactive iodine concentrates in the thyroid and can result in disease decades later.
The larger, earlier Hanford Thyroid Disease Study failed to find increased thyroid disease in people who lived downwind of Hanford.
The latest study, conducted by the Centers for Disease Control’s Agency for Toxic Substances and Disease Registry, found a statistically significant increase in thyroid disease in men who lived next to Hanford, said Greg Thomas of the agency’s Seattle office.
The increase was in underactive thyroids, a condition in which the thyroid produces too little thyroid hormone. Symptoms can include an enlarged thyroid, fatigue and weight gain.
The study collected health information from people who were born in Washington between 1945 and 1951 and lived in Adams, Benton or Franklin counties for at least one year. Those years are believed to have had the largest radioactive iodine releases from Hanford.
The information then was compared with people who were born and lived in Mason, San Juan or Whatcom counties – far from Hanford – at the same time.
The study included 1,160 people from all six counties. They were among 4,190 people randomly selected from birth records who proved eligible and could be interviewed.
Of the 291 men living near Hanford, the study found that 10 men had underactive thyroids, compared with 4 of 385 men in the counties far from Hanford.
Among women, 10 cases of underactive thyroids were found in 185 women who lived near Hanford. Twenty-three cases were found among 275 women who lived in the other counties. Underactive thyroids are much more common in women than men nationwide.
The study was conducted to address concerns among people who grew up downwind of Hanford that radiation releases may have caused autoimmune or heart disease. Because of the earlier Hanford Thyroid Disease Study, it was not looking specifically for a link to thyroid disease.
But the only autoimmune disease that showed up at a statistically significant level was underactive thyroid in men. There was no increase in heart disease, or other autoimmune disease, among those living close to Hanford.
The U.S. Department of Energy, meanwhile, is interested in learning more about how the new study was conducted, said spokeswoman Karen Lutz.