More than three years after the triple core meltdown in Fukushima Prefecture devastated the lives of thousands of residents, the effect that the radiation release is having on children’s thyroid glands still weighs heavily on residents’ minds.
The iodine-131 released into the air by the meltdowns accumulates in the thyroid gland, increasing the risk of thyroid cancer. The gland is responsible for regulating hormone levels in the body.
Children are considered especially vulnerable. After the 1986 Chernobyl disaster, more than 6,000 children were diagnosed with thyroid cancer by 2005, according to the U.N. Scientific Committee of the Effects of Atomic Radiation.
Given the local anxiety, the Fukushima Prefectural Government in October 2011 started offering free thyroid screenings for everyone who was 18 or younger at the time of the disaster. The prefecture has 370,000 residents in that age group, and 300,000 had received voluntary checkups by the end of March.
The program may look good on paper, but it has drawn flak from medical experts who say it is far from adequate in determining a link between the cancers found and radiation exposure.
At the core of the criticism is the prefectural government’s policy of not releasing data on the results of the checkups, such as what stage of cancer the examinees are in.
This lack of disclosure — based on prefectural privacy policies — has made it hard for experts to accurately judge whether the abnormally high incidence of thyroid cancer in Fukushima is being caused the nuclear debacle or the higher screening rate.
In addition, the prefecture has no authority to follow up on children who test positive for cancer, meaning its data on the medical effects of the aftermath of the disaster will be limited.
Papillary thyroid cancer, the type that appears most prevalent among children in Fukushima, is known for having a slow growth rate and very low risk of death, the experts say. Therefore, many hospitals in Japan nowadays tell patients that long-term observation of their condition is an option to surgery.
Iwao Sugitani, a professor and chairman of the department of endocrine surgery at Nippon Medical School Graduate School of Medicine, said about 90 percent of thyroid cancer cases in Japan involve papillary thyroid cancer. While around nine out of every 10 patients with this type of cancer face no immediate threat to their lives, experts are divided on whether to perform surgery in such cases.