The ministry released a map on Monday showing the contaminated land. It conducted a survey for radioactive cesium at some 2,200 locations mainly in Fukushima Prefecture in June and July.
But many experts warn that the crisis is just beginning. Professor Tim Mousseau, a biological scientist who has spent more than a decade researching the genetic impact of radiation around Chernobyl, says he worries that many people in Fukushima are "burying their heads in the sand." His Chernobyl research concluded that biodiversity and the numbers of insects and spiders had shrunk inside the irradiated zone, and the bird population showed evidence of genetic defects, including smaller brain sizes.
"The truth is that we don't have sufficient data to provide accurate information on the long-term impact," he says. "What we can say, though, is that there are very likely to be very significant long-term health impact from prolonged exposure."
NISA compares contamination to Hiroshima blast
The amount of radioactive cesium ejected by the Fukushima reactor meltdowns is about 168 times higher than that emitted in the atomic bombing of Hiroshima, the government's nuclear watchdog said Friday.
The Nuclear and Industrial Safety Agency provided the estimate at the request of a Diet panel but noted that making a simple comparison between an instantaneous bomb blast and a long-term accidental leak is problematic and could lead to "irrelevant" results.
The report said the crippled Fukushima No. 1 plant has released 15,000 terabecquerels of cesium-137, which lingers for decades and can cause cancer, compared with the 89 terabecquerels released by the U.S. atomic bombing of Hiroshima.
Radioactive caesium-137 released by the Fukushima nuclear energy plant catastrophe so far equals 168 Hiroshima bombs a Japanese news report said Thursday, reported by AFP as Japanese government argues that, since there was no explosion, the figures err and U.S. regulatory officials indicate an explosion at Fukushima probably did occur when the earthquake and tsunami triggered the world's worst nuclear accident since Chernobyl 25 years ago according to Thom Hartmann's interview Thursday with nuclear expert on Russia Today.
The administration suggested that government agencies intensify radiation testing of marine products from the targeted waters to protect public health in China.