Fukushima Watch: Early Data on Thyroid Cancer Released


A study by researchers in Fukushima prefecture found 57 minors in the prefecture have been diagnosed with thyroid cancer so far and another 46 are showing symptoms that suggest they may also have the disease.

Thyroid cancer can be caused by exposure to radiation, but it’s unclear whether the number is linked to the Fukushima Daiichi nuclear accident in March 2011 because the rate of thyroid cancer in the general population isn’t fully known.

“There is a possibility that early-stage cancer and small tumors were discovered because experienced doctors conducted thorough checkups using the newest machinery,” Chief Cabinet Secretary Yoshihide Suga said Monday at a regular news conference. The cabinet’s top spokesman said the government would keep a close eye on developments.

Fukushima prefecture has been conducting regular checkups of 367,707 people who were in Fukushima in March 2011 and were age 18 or under when the nuclear crisis struck. Approximately 296,000 have already been tested for thyroid cancer.

Of those, the prefecture said that 104 showed signs of thyroid cancer, of whom 36 were males and 68 were females. As of June, 58 of them had undergone surgery and all but one received a definite diagnosis of thyroid gland cancer. The size of tumors varied from 5.1 millimeters to 40.5 millimeters, according to the prefecture. All of those who underwent surgery are recovering smoothly, the prefecture said.

According to the American Thyroid Association, thyroid cancer is “usually very treatable and is often cured with surgery and, if indicated, radioactive iodine.”

The research found there was no regional difference between areas close to the nuclear power plant and those farther away. The percentage of those found to have thyroid cancer in the town of Okuma near the plant and the town of Inawashiro, located approximately 100 kilometers to the west, was 0.05% in each case.

It is difficult to determine whether that percentage is unusually high, since detailed research on this scale hasn’t taken place elsewhere. It is possible that a similar rate of thyroid cancer would be found in children who don’t live near a nuclear-power plant if all those children were examined.

Some medical experts have said that cases of thyroid cancer started to increase in Chernobyl only several years after the nuclear disaster there in 1986, suggesting it may be too soon to reach conclusions about Fukushima.

You can return to the main Market News page, or press the Back button on your browser.