Asia-Pacific News

Critics urge Japan to widen nuclear evacuation zone

By Takehiko Kambayashi Oct 20, 2011, 9:05 GMT

Tokyo - Scientists, environmentalists and citizens groups have called for Japanese authorities to evacuate more areas in the wake of March's nuclear accident after finding wider radiation contamination than officially reported.

Researchers have found up to 6.15 million becquerels per square metre of soil in Fukushima city, 60 kilometres north-west of a nuclear power plant that has been leaking radioactive material into the environment since it was damaged in an earthquake and tsunami in the spring.

The measurement is four times higher than the levels used to declare mandatory evacuation areas around Chernobyl, Ukraine, after the 1986 nuclear accident there, the Japanese branch of the environmental organization Friends of the Earth said.

'The government should encourage children and pregnant women to evacuate' the affected areas, Kanna Mitsuta, a Friends of the Earth researcher who participated in the survey, said Thursday.

Residents in the town's district of Watari also found their Geiger counters going off their scales, which go up to 10 microsieverts per hour, Mitsuta said.

By comparison, only 7 kilometres from the power plant and deep within the 20-kilometre exclusion zone around the nuclear station, radiation levels were recorded at 14.24 microsieverts per hour Wednesday.

Becquerels measure the units of radiation emitted from a substance. Sieverts measure the potential impact of the radiation on an exposed organism.

The research, which examined soil samples collected on September 14 from five locations in Fukushima, was led by Tomoya Yamauchi, professor and radiation expert at Kobe University.

Yamauchi has joined Friends of the Earth Japan and other civic groups in urging the evacuation of at least those most vulnerable to radiation exposure.

But local and central governments have decided not to, leading local activists and environmentalists to accuse them of not putting residents' health first.

Critics charged that authorities were more worried about the local economy, which could suffer if selected evacuations trigger a more general outflow of the population.

Tens of thousands of residents have already voluntarily left the prefecture around the Fukushima Daiichi Nuclear Power Station.

Many said they do not feel safe from radiation exposure anywhere in Fukushima prefecture, which lies about 250 kilometres north-east of Tokyo.

Prime Minister Yoshihiko Noda travelled Tuesday to Fukushima city to inspect decontamination efforts. 'I will make the utmost effort for decontamination,' he told locals.

The central government is reportedly to spend about 250 billion yen (3.3 billion dollars) on cleaning up radiation-tainted residential areas.

The whole of the Watari district would be among those decontaminated, said Seiji Nagashima, a Fukushima city official. But the city had not decided when the work would start, he said.

Critics argued the government's 'decontamination' is not effective in many areas. They see it as a stopgap measure.

Yamauchi said the contamination in the area is so severe that authorities need to remove not only the topsoil but also road surfaces, roofs and concrete walls.

Mitsuta expressed concern that the official cleanup is superficial and its effects only temporary.

'Radiation levels drop soon after decontamination work, but whenever it rains, contaminated soil flows into the area from surrounding mountain forests and the levels climb once again,' she said.

Experts and locals said woodlands that cover 71 per cent of Fukushima prefecture have been highly contaminated.

Most areas of the prefecture are showing radiation levels above 5.2 millisieverts per year, one leading critic said, adding that any area in a nuclear power plant showing those levels would be declared out of bounds to anyone under 18.

But the government has deliberately raised thresholds to minimize the economic impact on the prefecture, said Hiroaki Koide, an assistant professor at Kyoto University's Research Reactor Institute.

In mid-April, authorities said they set up the 20-kilometre no-go zone around the plant because that was where the risk of exposure was estimated to be more than 20 millisieverts per year.

Koide said that threshold is too high. But, he added, the government could not make it any lower, or most of the prefecture would have to be evacuated, causing a national-level crisis.

'So they believed that they had no choice but to expose residents to radiation,' he said.