Mark Willacy reported this story on Tuesday, November 5, 2013 08:06:00

TONY EASTLEY: One of the terrible legacies of the radioactive fallout from the Russian disaster at Chernobyl is now being visited upon people in Japan.



Researchers in Fukushima are uncovering higher than expected rates of thyroid cancer in children.



One prominent former thyroid surgeon - a veteran of the Chernobyl disaster - has told the ABC's Foreign Correspondent program that the number of cancer cases in Fukushima are emerging faster than expected.



But another cancer specialist says that the high rate is simply a product of widespread, sensitive screening and no-one should be alarmed.



The ABC's North Asia correspondent Mark Willacy reports from Fukushima.



(Sound of child crying)



MARK WILLACY: Two-year-old Yuta Koike is having none of it. Every time the nurse tries to run the probe over his neck he cries, kicks, and tries to slide off the bed.



His mother, Tomoko Koike, has brought Yuta and his four-year-old sister Saki in for a thyroid gland screening because she fears the fallout from the nearby Fukushima nuclear plant.



(Sound of Tomoko Koike speaking in Japanese).



"I am worried," she tells me, "but I believe they're okay. I am hoping they're okay," she adds.



Before the nuclear meltdowns, health authorities estimated thyroid cancer rates among Fukushima's children at between one and two cases in every million.



Since the disaster the Fukushima local government has carried out a large-scale screening program and with about 200,000 children tested, there have been 18 confirmed cases of thyroid cancer and 25 more suspected cases - an unexpectedly high rate.



Akira Sugenoya is the mayor of Matsumoto City in Nagano but he's also a respected thyroid surgeon who spent five years treating children in Ukraine and Belarus who developed thyroid cancer after the Chernobyl disaster.



(Sound of Akira Sugenoya speaking in Japanese).



"When I look at Fukushima now the number of thyroid cancer cases in kids is quite high," says Dr Sugenoya. "The doctors in Fukushima say that it shouldn't be emerging this fast, so they say it's not related to the accident. But that's very unscientific, and it's not a reason that we can accept," he says.



But other experts believe there's nothing to fear.



GERALDINE THOMAS: Following Fukushima I doubt that there'll be any rise in thyroid cancers in Japan.



MARK WILLACY: Professor Geraldine Thomas is a specialist in the molecular pathology of cancer at Imperial College London.



She also helped establish the Chernobyl Tissue Bank, which analyses samples from people exposed to radiation after the nuclear disaster in 1986.



She argues that there's a simple reason for the higher than expected incidence of thyroid cancer among Fukushima's children.



GERALDINE THOMAS: If you look for a problem, especially if you use an incredibly sensitive technique, which is what the Japanese are actually doing, you will find something.



MARK WILLACY: Everyone agrees that what's most important is detecting thyroid cancers early because if found in the early stages it's almost always successfully treated.



But as Foreign Correspondent discovered, Fukushima's health authorities are acting almost in secret, even refusing our request for a simple age breakdown of the thyroid cancer victims, citing privacy reasons.



This refusal to share basic data has aroused the suspicions of thyroid specialist Akira Sugenoya.



(Sound of Akira Sugenoya speaking in Japanese)



"I'm still very angry," says Dr Sugenoya. "I think they have this data, so it's very strange why they won't release it," he says.



And it's not just the thyroid data that has been kept secret, so too were the initial meetings of the Fukushima panel charged with screening the region's children.



For parents like Tomoko Koike, who are worried about the effect of the fallout on their young children, it smells like a cover up.



(Sound of Tomoko Koike speaking in Japanese)



"I do not think they're telling us everything," she says. "I cannot trust what they say. So it makes me worry about my kids' future. It depresses me," she says.



Adding to that worry for Tomoko Koike has been the discovery of cysts on the thyroid gland of her four-year-old daughter Saki.



While not regarded as malignant, the cysts will have to be monitored in the months and possibly years to come.



This is Mark Willacy in Fukushima for AM.



TONY EASTLEY: And Mark's full report can be seen tonight at 8 o'clock on Foreign Correspondent on ABC TV1.