In a study that began in April 2014 to check the impact of the 2011 Fukushima reactor meltdowns, 30 children have so far been diagnosed with thyroid cancer and 27 others are suspected of having the disease, according to a prefectural government panel.

Most of them were thought to be problem-free when their thyroid glands were checked during the first round of the study conducted over a three-year period through March 2014, the panel said Monday.

The first survey covered about 300,000 people who were under the age of 18 and living in Fukushima Prefecture when the nuclear disaster was triggered by the 3/11 earthquake and tsunami.