Study: Cancer up at meltdown sites

TOKYO -- A new study says children living near the Fukushima nuclear meltdowns have been diagnosed with thyroid cancer at a rate 20 to 50 times that of children elsewhere, a difference the authors contend undermines the government's position that more cases have been discovered in the area only because of stringent monitoring.

Most of the 370,000 children in Fukushima prefecture have been given ultrasound checkups since the March 2011 meltdowns at the tsunami-ravaged Fukushima Daiichi nuclear plant. The most recent statistics, released in August, show that thyroid cancer is suspected or confirmed in 137 of those children, a number that rose by 25 from a year earlier. Elsewhere, the disease occurs in only about 1 or 2 of every 1 million children per year by some estimates.

"This is more than expected and emerging faster than expected," lead author Toshihide Tsuda said during a visit to Tokyo. The study was released online this week and is being published in the November issue of Epidemiology, produced by the Herndon, Va.-based International Society for Environmental Epidemiology. The data come from tests overseen by Fukushima Medical University.

Making sense of the relationship between radiation and cancer is precarious: It's scientifically impossible to link an individual cancer case to radiation. Looking harder with routine checkups, like the one in Fukushima, leads to quicker discovery of tumors, inflating the tallies.

Right after the disaster, the lead doctor put in place in Fukushima, Shunichi Yamashita, repeatedly ruled out the possibility of radiation-induced illnesses.

But Tsuda, a professor at Okayama University, said the latest results from the ultrasound checkups raise doubts about the government's view.

Thyroid cancer among children is one sickness the medical world has definitively linked to radiation after the 1986 Chernobyl catastrophe. If treated, it is rarely fatal but patients are on medication for the rest of their lives.

Scientists are divided on Tsuda's conclusions.

In the same Epidemiology issue, Scott Davis, professor in the department of epidemiology in the Seattle-based School of Public Health, said the key limitation of Tsuda's study is the lack of individual-level data to estimate actual radiation doses.

Davis agreed with the findings of the World Health Organization and the United Nations Scientific Committee on the Effects of Atomic Radiation, both of which have carried out reviews on Fukushima and predicted cancer rates will remain stable, with no rises being discernible as radiation-caused.

David Brenner, professor of radiation biophysics at Columbia University Medical Center, took a different view. He said in a telephone interview that the higher thyroid cancer rate in Fukushima is "not due to screening. It's real."

Conclusions about any connection between Fukushima radiation and cancer will help determine compensation and other policies. Many people who live in areas deemed safe by the government have fled fearing sickness, especially for their children.

Noriko Matsumoto, 53, who used to work as a nurse in Koriyama, Fukushima, fled to Tokyo with her then-11-year-old daughter a few months after the disaster. She had initially shrugged off the fears but got worried when her daughter started getting nosebleeds and rashes.

"My daughter has the right to live free of radiation," she said. "We can never be sure about blaming radiation. But I personally feel radiation is behind sicknesses."

Andrew Olshan, professor in the department of epidemiology at the University of North Carolina at Chapel Hill, noted that research on what follows a catastrophe is complex and difficult.

"Dr. Tsuda's study had limitations including assessment of individual radiation dose levels to the thyroid and the ability to fully assess the impact of screening on the excess cases detected," he said.

"Nonetheless, this study is critical to initiate additional investigations of possible health effects, for governmental planning, and increasing public awareness."

A Section on 10/09/2015

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