FUKUSHIMA - An ongoing study on the impact of radiation on Fukushima residents from the crippled atomic power plant has found 12 minors with confirmed thyroid cancer diagnoses, up from three in a report in February, with 15 other suspected cases, up from seven, researchers announced Wednesday.
The figures were taken from about 174,000 people aged 18 or younger whose initial thyroid screening results have been confirmed.
Researchers at Fukushima Medical University, which has been taking the leading role in the study, have said they do not believe the most recent cases are related to the nuclear crisis.
They point out that thyroid cancer cases were not found among children hit by the 1986 Chernobyl nuclear accident until four to five years later.
The prefecture’s thyroid screenings target 360,000 people who were aged 18 or younger when the March 2011 mega-quake and tsunami triggered the meltdown crisis at Tokyo Electric Power Co.’s Fukushima No. 1 nuclear plant.
The initial-phase checks looked at lumps and other possible thyroid cancer symptoms and categorized possible cases into four groups depending on the degree of seriousness. Those in the two most serious groups were picked for secondary exams.
In fiscal 2011, after confirming test results from about 40,000 minors, the prefecture sent 205 for secondary testing. Of the 205, seven were diagnosed with thyroid cancer, four came out with suspected cases, and another had surgery but the tumor was found to be benign.
In fiscal 2012, of about 134,000 minors with confirmed initial screening results, the prefecture sent 935 to secondary testing. Among them, five were confirmed with thyroid cancer, while there were 11 suspected cases.
In the Chernobyl catastrophe, thyroid cancer was reported in more than 6,000 children. The U.N. Scientific Committee attributed many of the cases to consumption of milk contaminated with radioactive iodine immediately after the crisis started.
Last month, U.N. scientists assessing the health impact of the Fukushima nuclear crisis said the radiation dose for residents in the region was much lower than Chernobyl and that they do not expect to see any increase in cancer in the future.
Among those aged 10 to 14 in Japan, thyroid cancer strikes about 1 to 2 in a million.