TOKYO – The scars of Japan’s March 11 disaster are both glaringly evident and deceptively hidden.

Six months after a tsunami turned Japan’s northeast into a tangled mess of metal, concrete, wood and dirt, legions of workers have made steady progress hauling away a good portion of the more than 20 million tonnes of debris covering ravaged coastal areas. The Environment Ministry says it expects to have it all removed by next March, and completely disposed of by 2014.

But a weightless byproduct of this country’s March 11 disaster is expected to linger for much longer.

The Japanese learned a lot about the risks posed by radiation after the United States dropped atomic bombs on Hiroshima and Nagasaki in 1945. Now, once again, they are facing this invisible killer. This time, the mistake is of their own making.

"I’m afraid," says Shoji Sawada, a theoretical particle physicist who is opposed to the use of nuclear energy.

Sawada has been carefully monitoring the fallout from the accident at the Fukushima Daiichi power plant. "I think many people were exposed to radiation. I am afraid [they] will experience delayed effects, such as cancer and leukemia."

Evacuation zone Japan's government maintains a 20-kilometre evacuation zone around the Fukushima Daiichi plant, with no unauthorized entry allowed.

The government has urged people within a 30-km radius of the plant to leave, but it's not mandatory.

Some people say the evacuation zone should include Fukushima City, which is 63 km away from the plant. At the moment, the roughly 100,000 local children are kept indoors, schools have banned soccer and outdoor sports, pools were closed this summer, and building windows are generally kept closed.

A handful of people argue the government should evacuate all of Fukushima prefecture, which has a population of about 2 million.

Sawada dedicated his career to studying the impact radiation has on human health, particularly among the survivors of Japan’s atomic bombings. His interest is both professional and personal. When he was 13 years old, his mother urged him to flee their burning home in Hiroshima. She died, trapped beneath rubble.

"I think Tokyo Electric Power Company [TEPCO], as well as the Japanese government, made many mistakes," he says.

Those mistakes have been clearly documented since the earthquake and tsunami triggered meltdowns and explosions at TEPCO’s Fukushima Daiichi, some 220 kilometres northeast of Tokyo. Warnings to build a higher tsunami wall were ignored; concerns about the safety of aging reactors covered up; and a toothless nuclear watchdog exposed as being more concerned with promoting atomic energy than protecting the public.

The result: a nuclear crisis with an international threat level rating on par with the 1986 disaster in Chernobyl.

No-entry zone

Tens of thousands of people have evacuated a 20 km no-entry zone around Fukushima Daiichi. In addition, the Japanese government has told residents living between 20 and 30 km away from the facility, and in so-called radiation "hot spots" beyond that, to leave their homes. Some may never return.

"The two-kilometre region is highly polluted, so I think it will be very difficult for people to go back," Sawada says.

Then there are the concerns about the food supply. Unsafe levels of radioactive cesium, which has a half-life of about 30 years, have been detected in beef, milk, vegetables and tea leaves. Tokyo’s tap water was deemed dangerous for infants at one point. Sludge containing radioactive materials is building up at sewage facilities across Japan. And contaminants have been found in sandboxes at dozens of parks and school playgrounds in eastern Tokyo.

Government authorities insist they are taking precautions.

"We are doing our best, and counting and measuring the radiation level all the time," says Maeko Nakabayashi, who holds a seat in Japan’s legislature for the ruling Democratic Party (DPJ). "We are extending that to every food product so that people can feel better [and] be assured that the food that they are eating is safe."

Facts about the March 11 disaster The earthquake happened at 2:46 p.m. local time. The tsunami barreled inland about 30 to 45 minutes later.

15,781 people are confirmed dead, with 4,086 still unaccounted for.

83,000 people are living away from their homes, either because of the tsunami or the nuclear crisis.

158,000 people in Iwate, Miyagi and Fukushima prefectures have lost work or temporarily left work.

But not everyone is convinced, especially parents.

"The Japanese government has a long history of lying or hiding the truth," insists Gianni Simone, citing the cover-up of mercury poisoning in the 1950s and the HIV-tainted blood scandal of the 1980s. The freelance writer and Italian teacher lives just south of Tokyo with his wife, Hisako, and their eight and 10-year-old sons.

"We have started buying from food cooperatives whose products come from safe, or safer, prefectures located in the south," says Simone. "My wife [and] her friends check suspect food by using instruments bought by local residents and stores, and directly calls the companies to make sure that the food she bought at the supermarket is safe."

Simone and his wife are among a growing group of people in Japan who are carrying out independent tests on the food they eat and the air they breathe. They’d say they have good reason to be skeptical. The government and TEPCO dragged their heels for weeks before acknowledging three of Fukushima Daiichi’s reactors suffered meltdowns. In May, officials admitted they deliberately withheld forecasts on the spread of radiation.

"We did not provide the data to the public because we feared panic," said Goshi Hosono, who is now Japan’s nuclear crisis minister. "We will make sure all data will be provided to the people without delay."

Then last month, an investigation by the Associated Press suggested government authorities ignored their own computer forecasts and allowed thousands of people to stay for days in areas with high levels of radiation.

"In the initial stages, just after the hydrogen explosion, people needed to escape from the effect of radiation," says Professor Sawada. "They deceived people when the level of radiation was very high."

Decontamination

The Japanese government is now conducting extensive aerial surveys, from the northeast to the central part of the country, to track the spread of radiation from Fukushima Daiichi.

It’s also actively figuring out plans to decontaminate farmland, residential areas and public spaces around the nuclear plant, announcing it will power-wash buildings and scrape away topsoil from fields and playgrounds. It’s a mammoth job.

"The situation is more dire than most people would think," says Lloyd Helferty of Biochar Ontario. The Canadian engineering technologist is trying to encourage Japanese officials to use a natural soil additive that would speed up the growth of plants, such as fungus, so they quickly absorb radiation.

"The faster your plants grow, the faster you can take these things out of the ecosystem, essentially."

No matter how this toxic mess is cleaned up, it will no doubt take years. Then there’s the long, complicated and costly process of controlling and then decommissioning Fukushima Daiichi.

"The whole world is waiting for Japan to bring the nuclear accident under control," said Japan’s new prime minister, Yoshihiko Noda, last Thursday when he visited the plant. "The efforts of everyone here will be the key to whether the nation can overcome the challenge."

Monitoring the health of tens of thousands of citizens who lived around Fukushima Daiichi is another challenge facing the Noda administration. Already, small amounts of radioactive iodine have been detected in the thyroid glands of hundreds of children in Fukushima prefecture.

"People who were exposed to the radioactive matter should be taken care of by the government and checked once or twice a year," insists Professor Sawada. "Early detection is very important."

Rebuilding Japan’s northeast coast, which at first blush seemed a hopelessly overwhelming job, might prove to be the easy part of the recovery process. Dealing with the aftermath of its unprecedented nuclear accident will likely be much harder and take much longer.

Craig Dale is a senior producer with CBC's The National and is currently on loan to NHK, the Japanese public broadcaster, in Tokyo.