Fukushima Revives The Low-Dose Debate
May 20, 2011
Sciencemag.org - At 5 p.m. sharp, Mitsuru Itou watches as a technician steps inside a quartet of orange traffic cones and black-and-yellow traffic bars marking a “keep out” area in a gravel lot. Holding a radiation meter at his waist, the technician waits for the instrument to stabilize. Then every 30 seconds for the next 2½ minutes he recites the count.
At 5 p.m. sharp, Mitsuru Itou watches as a technician steps inside a quartet of orange traffic cones and black-and-yellow traffic bars marking a “keep out” area in a gravel lot. Holding a radiation meter at his waist, the technician waits for the instrument to stabilize. Then every 30 seconds for the next 2½ minutes he recites the count. Itou, a supervisor with the Public Health and Welfare Office of Fukushima Prefecture, correctly predicts that the readings will average 1.6 microsieverts per hour. “That's what [the radiation] has come down to for some time now,” he says. The results are phoned in to a disaster center, which posts them to its Web site. This ritual is repeated every hour at seven locations across the prefecture to track environmental radiation from the Fukushima Daiichi nuclear power plant, 63 kilometers southeast of Fukushima city. The measured levels range from two to 1000 times normal background radiation—and residents, officials, and scientists wonder what that may mean for public health.
...
Opportunities to narrow uncertainties have been missed. In the aftermath of the Soviet Union's April 1986 Chernobyl nuclear accident, which spewed radionuclides over a swath of Europe, “there was no continuity, no overarching panel looking at how science should be done,” says Ronald Chesser, a radiation biologist at Texas Tech University in Lubbock. The subsequent Soviet collapse, scarce funding, imprecise dosimetry, and difficulties tracking people over the years have limited the number of studies and their reliability, he says. The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) concluded in a 2008 report that over 6000 cases of thyroid cancer in young people could be linked to Chernobyl but that evidence for other cancers was inconclusive. To resolve outstanding questions, on 26 April the World Health Organization's International Agency for Research on Cancer in Lyon, France, asked the international community to support a Chernobyl Health Effects Research Foundation to conduct life-span studies, similar to those following A-bomb survivors in Japan.