Answer to Question #2260 Submitted to "Ask the Experts"

Q

I am 20 years old. I was hoping you could give me some information on the effects of Chernobyl and who was affected. In June of 1986, after the explosion, my family spent a month in Poland in the area of Poznan. I was four at the time and a picky eater, however I was very fond of milk and ate a lot of potatoes. A little more than two years ago, I had taken a blood test which tested positive for hypothyroidism. I take medication every day (it is a synthetic thyroid hormone, to give me what my body is not producing). I was also tested for enlargement and lumps on the gland. Luckily none was found. Is it possible that my hypothyroidism could be an effect from Chernobyl?

A

Based on the results of the several epidemiological studies reported to date, the main health effect of the April 1986 Chernobyl reactor accident has been found to be an increased risk of benign (noncancerous) and malignant (cancerous) thyroid tumors among young children who, at the time of the accident and for a few weeks afterwards, were living in the heavily contaminated areas of Belarus, particularly the Gomel oblast, and who drank milk from cows grazing in the area. The milk from such cows, together with airborne fallout materials, was the major source of radioactive iodines released during the accident. Such iodines when taken into the human body through the mouth or lungs are deposited primarily in the thyroid gland. Iodine-131, one of the principal radioactive forms of iodine, has a "half-life" of eight days, so the dose of radiation to the thyroid from iodine-131 taken into in the body and hence the risk of it causing thyroid tumors decreases quite rapidly after its release into the environment. Radiation doses to the thyroid that are many times greater than the dose one would receive from a chest x ray are necessary to damage the gland's function. To date there is no definitive epidemiological evidence of a link between reduced thyroid function (hypothyroidism) as a consequence of the accidental release of radioactive iodines from the Chernobyl reactor in 1986.

Thus, based on the information the you have provided and on my knowledge of the published results of relevant epidemiological studies, it would seem highly unlikely that your hypothyroidism diagnosed about two years ago is related to your month-long stay in the Poznan area of Poland approximately six weeks after the accident when you were four years old.

Shirley Fry, MD
Epidemiologist