Radiation Dose-Response Relationships for Thyroid Nodules and Autoimmune Thyroid Diseases in Hiroshima and Nagasaki Atomic Bomb Survivors

Here’s the link. The easiest way to read this study is to save the pdf and open it in a pdf-reader like Adobe or Foxit – it looks quite messy the way it’s set up on that page. They’ve analyzed the data of more than 4000 survivors of the bombings more than 50 years after the bombings – in itself an amazing feat. The main findings:

“Results: Thyroid diseases were identified in 1833 (44.8%) of the total participants (436 men [32.2% of men] and 1397 women [51.0% of women]) (P<.001). In 3185 participants, excluding persons exposed in utero, not in the city at the time of the atomic bombings, or with unknown radiation dose, the prevalence of all solid nodules, malignant tumors, benign nodules, and cysts was 14.6%, 2.2%, 4.9%, and 7.7%, respectively. The prevalence of positive thyroid antibodies, antithyroid antibody–positive hypothyroidism, and Graves disease was 28.2%, 3.2%, and 1.2%, respectively. A significant linear dose-response relationship was observed for the prevalence of all solid nodules, malignant tumors, benign nodules, and cysts (P<.001). We estimate that about 28% of all solid nodules, 37% of malignant tumors, 31% of benign nodules, and 25% of cysts are associated with radiation exposure at a mean and median thyroid radiation dose of 0.449 Sv and 0.087 Sv, respectively. No significant dose-response relationship was observed for positive antithyroid antibodies (P=.20), antithyroid antibody–positive hypothyroidism (P=.92), or Graves disease (P=.10).

Conclusions: A significant linear radiation dose response for thyroid nodules, including malignant tumors and benign nodules, exists in atomic bomb survivors. However, there is no significant dose response for autoimmune thyroid diseases."

Basically, the study says that almost half, 45%, of all the atomic bomb survivors from Hiroshima and Nagasaki who're still alive have some sort of thyroid disease. One of the things that surprised me when reading this study is that the lower the age of exposure, the higher the risk of developing malignancies later on. It makes perfect sense, I just hadn’t thought about that. The excess odds ratio pr. Sievert of developing solid nodules was almost four times as high among those exposed at the age of 0-9 than among those exposed at the age of 10-19. As an aside, when Chernobyl blew up I was less than one year old.

And now for something completely different (target group: Danish readers). Here are the titles of the top posts on the front page of the main Danish wordpress site right now:

1. Bla. om at have de forkerte forbilleder og at gøre krav på sin lykke.
2. Færdig med at tørre røv
3. “Du kommer ingen vegne med at have det nemt”
4. Køkkenombygning – vejs ende. Næsten
5. Jernskjorten
6. Der er hylder der skal findes