nuclear-news

Low level radiation increased leukaemia risk for nuclear cleanup workers

Chernobyl study shows need for caution in Fukushima
http://www.japantimes.co.jp/text/nn20121114f2.html# UKO27Xhzxqg.twitter Kyodo A study released Thursday by a U.S. research team links protracted exposure to low-level radiation to a higher risk of leukemia among workers engaged in the cleanup of the 1986 Chernobyl nuclear disaster, and points to the need to protect those involved in dealing with the Fukushima crisis.
In the U.S. study, scientists did a followup health
survey covering 110,645 cleanup workers through 2006 and found 137
developed leukemia.

After excluding genetic and other factors, it estimated that around 16
percent of the leukemia cases confirmed during the 20-year followup
period were attributable to radiation exposure from the disaster.

Most of the victims were involved in efforts to contain the Chernobyl
disaster until 1990. Their cumulative exposure was less than 200
millisieverts.

According to Tokyo Electric Power Co., around 6,000 workers are
currently involved in efforts to decommission the four crippled
reactors at the Fukushima No. 1 power plant.

After the March 2011 meltdowns and hydrogen explosions, the Health,
Labor and Welfare Ministry raised the allowable cumulative radiation
exposure threshold to 250 millisieverts for workers so Tepco wouldn’t
run out of workers too quickly because of overexposure.

After the government declared the completion of “Phase 2” of the road
map for containing the disaster, the limit was lowered last December
to 50 millisieverts per year and 100 millisieverts per five years, the
same level as before the crisis.

But six workers were exposed to more than 250 millisieverts.

“All of the six have already left the work site,” Tepco said. “At this
moment, there has been no observable impact on their health.”

By the end of September this year, 167 workers registered more than
100 millisieverts. Workers exposed to 50 to 100 millisieverts numbered
941.

High radiation zones, including the structures housing the reactors,
remain off-limits. As work progresses, concern will likely increase
about what to do to reduce the health risk of workers.

Tepco meanwhile apparently lacks adequate procedures and discipline to
minimize the radiation exposure. Reports show workers have either
misplaced dosimeters for measuring their radiation exposure or have
worked without them. There was also an ethically questionable case in
which dosimeters were covered by a lead sheet to suppress exposure
readings, so workers could undertake operations beyond the exposure
limit.

“In Japan, nobody exactly knows workers’ conditions at nuclear
facilities,” said Masako Sawai of Citizens’ Nuclear Information
Center. “Even after the Fukushima crisis started, there have been
moves to conceal exposure. In that sense, the latest U.S. data are
very instructive and show the need for Japan to grasp what is going
on.”

Earlier this month, a 46-year-old man from Iwaki, Fukushima
Prefecture, pleaded for better conditions at Fukushima No. 1. He said
he was told to ignore dosimeter alerts and continue working in a
high-radiation environment.

He told reporters Nov. 1 at the health ministry, “Rank-and-file people
cannot raise their voices even when there is a problem.” He filed a
complaint with a Fukushima labor office against Tepco and Kandenko
Co., the Tepco subcontractor that oversaw the man’s work

November 16, 2012 - Posted by Christina Macpherson | employment, health, Japan, Ukraine