KAMAKURA, KANAGAWA PREF. – Lingering concerns about radiation a year into the Fukushima nuclear crisis have prompted people even as far away as the Tokyo area, some 100 to 250 km from the Fukushima No. 1 power plant, to move away.

Mamiko Joosten, who has lived for seven years in Kamakura, Kanagawa Prefecture, has now decided to move to Okinawa with her 6-year-old daughter out of fear of radiation, leaving her husband behind.

“I do not want to regret later on exposing my daughter to the threat of radiation. The government’s limit does not guarantee absolute safety, so I would rather choose to leave,” she said.

Her husband, Maurice, said that though “it is difficult” to be apart from his wife and daughter, he has opted to stay behind because he likes his current job, which he said is “not something I can easily find in Okinawa.”

Joosten said she lost her trust in the government after it failed to properly disclose information as the triple-meltdown crisis was unfolding, including data from the System for Prediction of Environmental Emergency Dose Information, known as SPEEDI, which predicts the dispersion of radioactive materials.

To move to Okinawa this month, she quit her job at an organic food store and will have to stop teaching maternity yoga lessons in Kamakura.

According to the Internal Affairs and Communications Ministry, the number of people moving to Tokyo and its vicinity exceeded those moving out by a smaller margin in 2011 than the year before. In Chiba Prefecture, where some radiation hot spots have been detected, people moving out exceeded newcomers for the first time in 55 years, by nearly 4,000.

In western Japan, Osaka, Kyoto and Okayama prefectures saw more incoming people than outbound ones for the first time in about 15 years. Except for Nagasaki Prefecture, Kyushu and Okinawa Prefecture also saw an increase in the number of new residents in 2011.

Hiroshi Takahashi, secretary general of a Tokyo-based nonprofit organization supporting people moving to rural areas, said that after the March 2011 earthquake and tsunami triggered the nuclear crisis, “inquiries from people considering moving out of Tokyo and its vicinity have surged.”

“Popular destinations have shifted from elsewhere in eastern Japan to western regions due to the nuclear crisis,” he said.

Before her decision, Joosten stayed in Okinawa with her daughter for a month and a half starting in mid-December to explore the possibility of relocating to the prefecture. She found many others had also moved from the Kanto region.

She is determined to move but also learned that relocation is not always easy, saying she heard that some families have struggled to find work, while mothers with kids have had a hard time living away from their husbands.

After coming back to Kamakura to prepare for the move, she shared her experiences in February with more than a dozen mothers also concerned about the harmful effects of radiation.

Mothers asked many questions about possible job opportunities, schools for their children and whether they could be accepted easily into the local community. Some said they are also planning to try staying in Okinawa for a month or so in April.

It is not an easy step for many to take.

Eriko Tajima, 40, a mother of two, said that while she hopes to relocate sometime in the future, she is unable do so immediately because her husband can’t quit his job.

“We would not mind if it were only us adults. I am concerned about the future of my kids. I don’t want them to spend most of their life being sick,” she said.

Anxious about internal radiation exposure, she only buys vegetables from western Japan and has stopped eating seafood.

Megumi Umeda, 28, who participated in one of the sessions organized by Joosten, said she would also feel more at ease if she could move farther away from Fukushima, but financial reasons and her husband’s work prevent her from doing so.

“I am searching for ways I can live here safely with my children. If I can change the future of my kids by what I do, I will do all I can.”

She now refrains from drinking tap water and makes lunches for her kids.

Some of the mothers said they have suffered depression as a result of their worries as well as the perception others have of them that they are overreacting.

According to the Ministry of Education, Culture, Sports, Science and Technology, the radiation dose in the air was about 0.050 microsievert per hour at monitoring spots in Tokyo and Kanagawa and Saitama prefectures as of early March, equivalent to 438 microsieverts for a full year.

The International Commission on Radiological Protection (ICRP), sets radiation exposure under normal situations at 1 millisievert per year and says 100 millisieverts of exposure over a lifetime would increase the possibility of developing cancer by 0.5 percent.

The government has ordered residents in areas reaching 20 millisieverts of annual radiation exposure to evacuate, based on the ICRP’s standard, which sets a limit of 20 to 100 millisieverts of annual radiation exposure under emergency situations.

However, scientists are at odds about the possible effects of low-level radiation exposure and internal exposure, which occurs by inhaling, eating or drinking radioactive substances. Some also pose questions about the credibility of the ICRP, which disregards the higher threat posed by internal exposure pointed out by the European Committee on Radiation Risk.

Kazuko Ono, a professor at Kyoto College of Medical Science, said there is no need to worry about radiation exposure for people outside the areas designated for evacuation by the government. She said negative repercussions to human health will be seen only with exposure of more than 100 millisieverts.

On the other hand, Katsuma Yagasaki, a professor emeritus at the University of the Ryukyus in Okinawa, pointed out possible dangers even in the Kanto region.

“The government’s standard disregards the effects of internal radiation exposure, which can be more dangerous than external exposure. Some kind of risk may emerge later. The government is not placing the first priority on the safety of people’s lives,” he said.

With differing views even among scientists, regular people have no choice but to decide on their own.

“I don’t want to blame anyone else if something goes wrong with my daughter in the future. So I am making my own decision,” Joosten said.