Then came the test result: the level of radioactive cesium in a patch of dirt just meters from where his 11-year-old son, Koshiro, played baseball was equal to those in some contaminated areas around Chernobyl.
The patch of ground was one of more than 20 spots in and around the nation’s capital that the citizen’s group, and the respected nuclear research center they worked with, found were contaminated with potentially harmful levels of radioactive cesium.
It has been clear since the early days of the nuclear accident, the world’s second worst after Chernobyl, that that the vagaries of wind and rain had scattered worrisome amounts of radioactive materials in unexpected patterns far outside the evacuation zone 12 miles around the stricken plant. But reports that substantial amounts of cesium had accumulated as far away as densely populated Tokyo have raised new concerns about how far the contamination had spread, possibly settling in areas where the government has not even considered looking.
The government’s failure to act quickly, a growing chorus of scientists say, may be exposing many more people than originally believed to potentially harmful radiation. It is also part of a pattern: Japan’s leaders have continually insisted that the fallout from Fukushima would not spread far, or pose a health threat to residents, or contaminate the food chain. And officials have repeatedly been proved wrong by independent experts and citizens’ groups that conduct testing on their own.
“Radioactive substances are entering people’s bodies from the air, from the food. It’s everywhere,” said Kiyoshi Toda, a radiation expert at Nagasaki University’s faculty of environmental studies and a medical doctor. “But the government doesn’t even try to inform the public how much radiation they’re exposed to.
The reports of hot spots do not indicate how widespread contamination is in the capital; more sampling would be needed to determine that. But they raise the prospect that people living near concentrated amounts of cesium are being exposed to levels of radiation above accepted international standards meant to protect people from cancer and other illnesses.
Japanese nuclear experts and activists have begun agitating for more comprehensive testing in Tokyo and elsewhere, and a cleanup if necessary. Robert Alvarez, a former special assistant to the United State Secretary of Energy and a nuclear expert, echoed those calls, saying the Defense Project’s measurements “raise major and unprecedented concerns about the aftermath of the Fukushima nuclear disaster.”
The government has not ignored citizens’ pleas entirely; it recently completed aerial testing in eastern Japan, including Tokyo. But several experts and activists say the tests are unlikely to be sensitive enough to be useful in finding micro hot spots such as those found by the citizens’ group.
Kaoru Noguchi, head of Tokyo’s health and safety section, however, argues that the testing already done is sufficient. Because Tokyo is so developed, she says, radioactive material was much more likely to have fallen on concrete, then washed away. She also said exposure was likely to be limited.
“Nobody stands in one spot all day,” she said. “And nobody eats dirt.”
Tokyo residents knew soon after the March 11 accident, when a tsunami knocked out the crucial cooling systems at the Fukushima plant, that they were being exposed to radioactive materials. Researchers detected a spike in radiation levels on March 15. Then as rain drizzled down on the evening of March 21, radioactive material again fell on the city.
In the following week, however, radioactivity in the air and water dropped rapidly. Most in the city put aside their jitters, some openly scornful of those — mostly foreigners — who had fled Tokyo in the early days of the disaster.
But not everyone was convinced. Some Tokyo residents bought dosimeters. The Radiation Defense Project, which grew out of a Facebook discussion page, decided to be more proactive. In consultation with the Yokohama-based Isotope Research Institute, members collected soil samples from near their own homes and submitted them for testing.
Matthew L. Wald contributed reporting from Washington, and Kantaro Suzuki from Tokyo.
