Tokyo: Farmland in parts of Japan is no
longer safe because of high levels of radiation in the soil, scientists have warned, as the country struggles to recover
from the Fukushima atomic disaster.
A team of international researchers said food production would likely be "severely impaired" by the elevated levels of caesium found in soil samples across eastern Fukushima in the
wake of meltdowns at the tsunami-hit plant.
The study, published in the Proceedings of National Academy of Sciences journal, suggests farming in neighbouring areas may also suffer because of radiation, although levels
discovered there were within legal limits.
"Fukushima prefecture as a whole is highly contaminated,"
especially to the northwest of the nuclear power plant, the
The study looked at caesium-137, which has a half life of 30 years and therefore affects the environment for decades.
The legal limit for concentrations in soil of the sum of
caesium-134 and caesium-137, which are always produced
together, is 5,000 becquerels per kilogram in Japan.
"The east Fukushima prefecture exceeded this limit and
some neighbouring prefectures such as Miyagi, Tochigi and
Ibaraki are partially close to the limit under our upper-bound
estimate," the study said.
"Estimated and observed contaminations in the western
parts of Japan were not as serious, even though some prefectures were likely effected to some extent," it added.
"Concentration in these areas are below 25 becquerels per
kilogram, which is far below the threshold for farming.
However, we strongly recommend each prefecture to quickly
carry out some supplementary soil samplings at city levels to
validate our estimates."
The study said "food production in eastern Fukushima
prefecture is likely severely impaired by the caesium-137
loads of more than 2,500 becquerels per kilogram".
The study was led by Teppei Yasunari of the Universities Space Research Association in the US state of