Japan Triples Airborne Radiation Checks as
‘Hot Spots’ Spread
Fukushima Power Plant
Electromagnetic Radiation Protection
Electromagnetic Field Meter
Inajima and Yuji Okada -
Aug 24, 2011
Japan will more than triple the number of regions it
checks for airborne radiation as more contaminated “hot
spots” are discovered far from Tokyo Electric Power Co.’s
crippled Fukushima nuclear power station.
The government said it will increase radiation monitoring
by helicopter to 22 prefectures from the six closest to the
plant, which began spewing radiation after an earthquake and
tsunami struck the station in March. The plan comes after
radioactive waste more than double the regulatory limit was
found 200 kilometers (125 miles) from the plant this week.
Authorities have refused to give a cumulative figure for
radiation released from the Fukushima Dai-ichi nuclear plant
after estimating in June that fallout in the six days
following the quake was equal to 15 percent of total
radiation released in the Chernobyl nuclear disaster in
1986. The authorities have been too slow to widen airborne
radiation testing, said Tetsuo Ito, the head of Kinki
University’s Atomic Energy Research Institute in Osaka.
“The government should have expanded the monitoring area
by helicopters much earlier to ease concerns among the
public,” Ito said in a telephone interview yesterday.
Officials on Aug. 12 found compost in a kindergarten yard
in Tokamachi city, Niigata prefecture containing radioactive
cesium measuring 27,000 becquerels per kilogram, Kenichiro
Kasuga, an official at the city’s disaster prevention
department, said by phone.
Under Japanese law, waste measuring over 8,000 becquerels
per kilogram must be treated as radioactive waste and can’t
be buried in a landfill.
City officials found sludge measuring 18,900 becquerels
per kilogram from radioactive cesium on the same day as part
of tests done at 60 educational and childcare facilities,
Kasuga said. The city government is storing the waste in
drums until the government sets final guidelines for its
disposal, he said.
“We still don’t know why this level of cesium was found
in the compost,” Kasuga said.
The hotspots in Niigata were likely caused by wind
blowing northwest towards the prefecture in the days
following the Fukushima accident, Kinki University’s Ito
The government will begin monitoring radiation levels in
16 prefectures from Aomori, in the far north of the main
island of Honshu, to Aichi in central Japan 460 kilometers
(290 miles) from the plant by the end of October, the
Ministry of Education, Culture, Sports, Science and
Technology said in a statement on its website yesterday.
Radiation monitoring has taken place in four other
prefectures and in Gunma and the western part of Fukushima
prefecture, said Hirotaka Oku, a spokesman at the science
and technology ministry.
Checks in Ibaraki and Yamagata prefecture were completed
in August and the findings will be released soon, he said,
without specifying when.
The discovery of radiation at Niigata kindergartens
coincides with the start of the rice harvest in the
prefecture that was the country’s biggest producer last year
with 7 percent of the total. Radiation from Dai-Ichi has
already been found in food including beef, tea and spinach.
So far, early tests on rice haven’t detected radiation,
Shingo Gocho, assistant director in Niigata prefecture’s
agricultural division said by phone yesterday. The
government is taking samples from 45 areas in 29 villages,
towns and cities that make up the prefecture’s growing area,
he said. The crops won’t be shipped until the results are
known, he said.
Japan’s Ministry of Health, Labour and Welfare plans to
conduct radiation checks in food produced in about 100
cities, towns and villages in 14 prefectures because local
governments hadn’t tested produce by the end of July despite
requests by the central government, said an official at the
ministry, who declined to be identified, citing internal
The central government will become move involved in
testing food to ease concerns among consumers and provide
more data, the official said. Radiation checks on produce
including vegetables, meat and eggs will be carried out at
the National Institute of Health Sciences and the findings
will be released as soon as possible, the official said.
Tokyo Electric’s Dai-Ichi plant released about 770,000
tera becquerels of radioactive materials between March 11
and March 16, Japan’s Nuclear and Industrial Safety Agency
said on June 6.
Japan’s government is under-reporting the amount of
airborne radiation across the country, said Tom Gill, an
anthropology professor at Meiji Gakuin University in Tokyo,
citing his studies in Fukushima prefecture since March.
The “maximum” radiation level given for Fukushima
prefecture on Aug. 13 was 2.64 microsieverts per hour in the
village of Iitate 40 kilometers northwest of the Dai-Ichi
plant, Gill said, according to figures from the Science
Ministry published daily in national newspapers.
That compares with the official reading in the village
itself the next day of 14.2 microsieverts per hour, he said,
showing a picture he took of the reading on that day. He was
speaking at a presentation in Yokohama near Tokyo on Aug.
The government excludes the highest readings among 20
measuring stations in the village from the data it collates
for publication, Gill said.
“Distrust and cynicism of central government is pretty
much universal across Fukushima now,” he said.
Medical tests on children living in three towns near the
plant between March 24 and 30 found 45 percent of those
surveyed suffered low-level thyroid radiation exposure,
Japan’s government said earlier this month.
Children are more susceptible to poisoning from
radioactive iodine, which can accumulate in the thyroid and
cause cancer, according to the
World Health Organization. None of the children’s
thyroid glands exceeded the safety threshold of 0.2
microsievert per hour set by the Nuclear Safety Commission
of Japan, the government said at the time.
The Fukushima disaster is the worst since a reactor
exploded at Chernobyl in the former Soviet Union 25 years
ago. About 2 million people in Ukraine are still under
permanent medical monitoring, according to the nation’s
embassy in Tokyo.
A becquerel represents one radioactive decay per second,
which involves the release of atomic energy that can damage
human cells and DNA, with prolonged exposure causing
leukemia and other forms of cancer, the
World Nuclear Association says.