JPR SYMPOSIUM Current status and future control of cesium contaminationin plants and algae in Fukushima

As plant scientists who faced the Fukushima nuclear disaster

Tetsuro Mimura • Toru Fujiwara • Hiroo Fukuda

Received: 1 October 2013 / Published online: 14 December 2013

� The Botanical Society of Japan and Springer Japan 2013

Keywords 137Cs � 134Cs � F1NPP � Fukushima Daiichi

Nuclear Power Plant � Plant science � Radionuclides

About two and half years ago, on March 11, 2011 a huge

earthquake and tsunami hit the north east of Honshu Island

in Japan. This natural disaster had catastrophic conse-

quences for the area of impact. Severe damage to the

Fukushima 1 Nuclear Power Plant (F1NPP) resulted in the

release of huge levels of radioactivity in the form of 137Cs,134Cs and 131I across a wide area of Fukushima prefecture

and neighboring regions.

In response to this radioactive contamination, concerned

scientists from various fields, including medicine, agricul-

ture, geoscience etc., began investigating ways to under-

stand and to mitigate the potential adverse effects on nature

and society.

Since the disaster, a number of Japanese plant scientists

have been independently working in the Fukushima area.

As one of these voluntary groups, we assembled

immediately after the accident to determine the impact of

the radioactive contamination on wild and cultivated plants.

In this JPR symposium, the results of our two-year

investigation are presented, as well as those from inde-

pendent groups from two other universities.

There were three main aims to our investigations: (1)

precise evaluation of radioactive contamination of wild

terrestrial plants and oceanic algae in the Fukushima area,

(2) estimation of the phytoremediation capacity of micro-

algae, field grasses, weeds, vegetables and rice plants, and

(3) finding of agricultural production techniques that limit

the accumulation of radionuclides in plants, as well as

finding plant varieties that naturally absorb only low levels

of radionuclides.

In the 1960s and 70s tests of nuclear bombs were fre-

quently conducted, and in 1986 the worst accident at a

nuclear power plant occurred at Chernobyl in Ukraine.

Information on plant and animal accumulation of radio-

isotopes following tests of nuclear bombs or the Chernobyl

accident is limited and it is difficult to judge whether that

information is applicable to Fukushima, or not.

Throughout this period, there have been many studies in

Japan on radioisotopic accumulation in plants. By 2011,

there was already much data on the Cs accumulation abil-

ities of plants. However, most of these results were from

experiments conducted under controlled environments.

To improve our understanding of plant radioisotope

uptake, we decided that we should measure radioactive

contamination and the phytoremediation abilities of vari-

ous plants in the Fukushima area directly. After two years,

we now know that in Fukushima, decontamination of ra-

diocesium by phytoremediation is not a realistic strategy to

be completed in several years. On the positive side, we

found that the accumulation of radiocesium by brown rice

and some vegetables was not high. We have also acquired

‘Fukushima Daiichi Nuclear Power Station’ is cited as ‘Fukushima 1

Nuclear Power Plant’ in the present manuscript.

T. Mimura (&)

Department of Biology, Graduate School of Science,

Kobe University, Rokkodai, Nada, Kobe 657-8501, Japan

e-mail: mimura@kobe-u.ac.jp

T. Fujiwara

Department of Applied Biological Chemistry, Graduate School

of Agricultural and Life Sciences, The University of Tokyo,

Tokyo, Japan

H. Fukuda

Department of Biological Sciences, Graduate School of Science,

The University of Tokyo, Tokyo, Japan

123

J Plant Res (2014) 127:3–4

DOI 10.1007/s10265-013-0606-y

information that may be useful for reducing radiocontam-

ination of rice cultivated in the Fukushima area. Further,

our trials using many varieties of rice plants may open

possibilities to analyze the molecular mechanisms of Cs

transport and metabolism, with the aim of developing

transgenic plants with low Cs accumulation (for food

safety) or high Cs accumulation (for phytoremediation).

We believe that it is our duty as plant scientists to document

what happened in Fukushima and to describe the changes that

occurred subsequent to the accident. Although we cannot

predict whether such an event will occur again somewhere,

the information that we have gained will undoubtedly be

valuable in understanding the potential impact of release of

radioactive material into the environment.

Our activities in Fukushima would not have been pos-

sible without the generous support of the people living in

Fukushima, students and co-workers who are not authors in

this symposium. We were also financially supported by

various organizations. We greatly appreciate their long-

lasting contributions.

1 October 2013

On be half of collaborators,

Tetsuro Mimura, Kobe University

Toru Fujiwara, The University of Tokyo

Hiroo Fukuda, The University of Tokyo

4 J Plant Res (2014) 127:3–4

123