nuclear-news

Fukushima workers with high internal radiation doses

High thyroid radiation doses in 178 Fukushima workers Asahi Shimbun, December 01, 2012
By YURI OIWA Dozens of workers received potentially cancerous doses of radiation to
their thyroid glands during recovery work at the Fukushima No. 1 nuclear power plant, according to data submitted to the World Health
Organization.

Tests on workers suspected of having high whole-body internal doses
found 178 individuals whose thyroid glands displayed doses greater
than 100 millisieverts, the generally accepted threshold for a raised
risk of thyroid cancer.

The highest recorded dose was 11,800 millisieverts, a level that would
give a correspondingly high probability of thyroid cancer.

Plant operator Tokyo Electric Power Co. submitted the data on thyroid
tests for 522 workers—both its own staff and contractors—to the WHO
upon request. ….
The WHO assessed the probability of these people developing thyroid
cancer by reviewing medical records from the Hiroshima and Nagasaki
atomic blasts. It calculated the risk for people in three separate age
categories—aged 20, 40 or 60 at the time of exposure.

It said a 20-year-old who receives a dose of 11,800 millisieverts will
be 34 times more likely to develop thyroid cancer within 15 years.
…..
“Some epidemiological studies suggest that radiation exposure can
increase the risk of thyroid cancer for people aged 40 or older, too,”
said Yoshio Hosoi, a professor at Hiroshima University’s Research
Institute for Radiation Biology and Medicine. “In addition tochildren, adults need to receive continued tests if their thyroid
gland radiation doses are 100 millisieverts or higher.”

TEPCO said it plans to offer workers thyroid gland ultrasound
examinations free of charge if their whole-body radiation doses are 50
millisieverts or higher.

However, at least one expert said that may not include all people at risk.

“There is a possibility that the thyroid gland radiation dose is 100
millisieverts even if the whole-body dose is only 5 millisieverts,”
said Saburo Murata, deputy director of Hannan Chuo Hospital.

Murata called on TEPCO to release all past test results—and those of
tests in the future.
http://ajw.asahi.com/article/0311disaster/life_and_death/AJ201212010050

December 3, 2012 - Posted by Christina MacPherson | Fukushima 2012, health, Japan