WIKIMEDIA, AKIRA KOUCHIYAMAThe release of radioactive materials from the Fukushima Daiichi nuclear power plant 2 years ago this month is unlikely to cause a significant cancer burden, according to a 172-page report released yesterday (February 28) by the World Health Organization (WHO). While workers who were directly involved with the disaster may be at higher risk of leukemia, thyroid cancer, and all solid cancers, even those living near the plant should be safe, the WHO concluded.
“Outside the geographical areas most affected by radiation, even in locations within Fukushima prefecture, the predicted risks remain low and no observable increases in cancer above natural variation in baseline rates are anticipated,” the report’s summary read.
But not everyone’s mind is put at ease. “The WHO report shamelessly downplays the impact of early radioactive releases from the Fukushima disaster on people inside the 20 km evacuation zone who were not able to leave the area quickly,” Rianne Teule, Greenpeace International nuclear radiation expert, said in a statement. On the other hand, radiation biologist Kazuo Sakai of Japan's National Institute of Radiological Sciences told ScienceInsider that the report may actually overstate some of the risks by using preliminary data that may have overestimated radiation exposure. Actual measurements of the radiation leakage have proven to be less than the preliminary estimates used in this report, and the WHO’s calculations further assume 4 months of exposure, when in reality, most infants were evacuated in a much more timely fashion, he said.
The report was drafted by a team of 13 experts who calculated no observable health effects for residents outside the vicinity of the plant, and minimal increases of risk for those in the immediate area. For exposed male infants, the WHO calculated a lifetime risk increase of around 7 percent for leukemia. Exposed female infants may face a 6 percent risk increase for breast cancer, a 4 percent increase for all solid cancers, and a 70 percent increase of thyroid cancer. These numbers represent increases over baseline rates, meaning they are still quite low. For example, unexposed individuals have a lifetime risk of thyroid cancer of just 0.75 percent, meaning a 70 percent increase for exposed female infants puts them at a lifetime risk of 1.25 percent.