Thyroid Cancer Risk Jumps 10-fold for Fukushima Workers

Close to 10 percent of the nearly 20,000 people who have worked at Japan's wrecked Fukushima Daiichi nuclear power station face an elevated risk of developing thyroid cancer, the power plant's operator Tokyo Electric Power Company (TEPCO) reported Friday.

TEPCO said 1,973 people employed in emergency crews involved in the clean-up since the meltdowns at the nuclear plant were exposed to enough radiation to cause potential problems, the AFP reported.

Each of these emergency workers was exposed to at least 100 millisieverts of radiation, a threshold the International Commission on Radiological Protection considers dangerous. TEPCO said it will offer workers a chance to undergo additional testing to determine the degree of internal contamination. 

Previous estimates about increased instances of thyroid cancer by TEPCO were too conservative, and the new toll reflects a 10-fold increase in the previous estimate. The initial estimate suggested a total of 178 Fukushima workers were exposed to more than 100 millisieverts of radiation.

Since the nuclear campus and its cooling system was overcome by a devastating tsunami more than two years ago, 19,592 people have worked at the Fukushima facility. Ten of thousands of locals were forced to evacuate the area around the Daiichi plant, most of whom have yet to be allowed to return.

The Fukushima incident was the worst nuclear disaster in a generation, bested in recent memory only by the Chernobyl disaster in 1986.

A seemingly never-ending stream of problems continue to hamper the stricken nuclear campus, including power outages, leaking contaminated water and groundwater testing positive for radioactive elements.

The latest setback arose this week when a mysterious steam-like gas was detected emanating from Unit 3, which contains a crippled nuclear reactor. The source of the steam has yet to be confirmed, but TEPCO officials suspect it is the result of rainwater somehow leaking into the reactor building.

It will take no less than four decades before the Fukushima plant is completely decommissioned. Nearly 3,500 people are currently working to dismantle the system.