ウォール・ストリート・ジャーナル日本版8月19日の記事(by Yuka Hayashi)です。
福島原発事故で周辺居住の45%の子供が内部被ばく
http://jp.wsj.com/Japan/node_291982
[東京] 日本政府は、大事故となった東京電力福島第1原発周辺の3市町村に住む子どもの半数近くが事故発生後間もなく低水準ながら放射線の内部被ばくを受けていたことを明らかにした。これにより周辺住民の放射線被ばくの長期的影響に対する不安が増大することは確実だ。
この調査は3月24~30日に、福島第1原発から20キロメートル圏の政府が避難指示を出した地域の外にあるいわき市と川俣町、飯舘村の3市町村の1150人の子どもを対象に実施した。
その時点で政府は全員が健康基準をクリアしたと発表していたが、その後、子どもの親や放射線専門家からより詳しい検査結果を公表するよう要求が寄せられていた。
今週になって発表されたその詳細によると、1150人のうち低レベルながら45%の子どもが内部被ばくをしていた。26%の子どもは毎時0.01マイクロシーベルト、11%が0.02マイクロシーベルトだった。最高は0.1マイクロシーベルトだったが、政府が健康へのリスクの基準としている0.2マイクロシーベルトは大幅に下回っていた。
放射線を皮膚に浴びる外部被ばくと違い、放射性物質を呼吸や飲食によって体内に取り込む内部被ばくは、健康への影響がより重いとされている。
ただ、広島大学原爆放射線医学研究所の細井義夫教授は今回の調査結果について、発表通りの数値なら被ばくした子どもが将来甲状腺ガンにかかる確率は極めて低いと思うと語った。
「発表通りの数値なら被ばくした子どもが将来甲状腺ガンにかかる確率は極めて低いと思う」と言う広島大学の細井教授に言いたいです-
「安全の基準は何ですか?避難する必要がないくらい安全なら、何故福島の人たちはモルモットのように検査されるのですか?」
「現在の数値が低いとしても、1日1日その数値は加算されていくのではないのでしょうか?」
「甲状腺ガンにかかる確率が低いといっても、それは被ばくにより、将来甲状腺ガンにかかる子どもが確実に出るということです。福島の子どもをロシアン・ルーレットの標的にする手助けはしないでください。」
と。
関連して、アルジャジーラの8月18日の記事も貼り付けます:
Fukushima radiation alarms doctors
http://english.aljazeera.net/indepth/features/2011/08/201181665921711896.html
抜粋:
・・・Doctors in Japan are already treating patients suffering health effects they attribute to radiation from the ongoing nuclear disaster.
"We have begun to see increased nosebleeds, stubborn cases of diarrhoea, and flu-like symptoms in children," Dr Yuko Yanagisawa, a physician at Funabashi Futawa Hospital in Chiba Prefecture, told Al Jazeera.
She attributes the symptoms to radiation exposure, and added: "We are encountering new situations we cannot explain with the body of knowledge we have relied upon up until now."
"The situation at the Daiichi Nuclear facility in Fukushima has not yet been fully stabilised, and we can't yet see an end in sight," Yanagisawa said. "Because the nuclear material has not yet been encapsulated, radiation continues to stream into the environment."
Health concerns
Al Jazeera's Aela Callan, reporting from Japan's Ibaraki prefecture, said of the recently detected high radiation readings: "It is now looking more likely that this area has been this radioactive since the earthquake and tsunami, but no one realised until now."
Workers at Fukushima are only allowed to be exposed to 250 mSv of ionising radiation per year.
Junichi Matsumoto, a TEPCO spokesman, said the high dose was discovered in an area that does not hamper recovery efforts at the stricken plant.
Yet radioactive cesium exceeding the government limit was detected in processed tea made in Tochigi City, about 160km from the troubled Fukushima Daiichi nuclear plant, according to the Tochigi Prefectural Government, who said radioactive cesium was detected in tea processed from leaves harvested in the city in early July.
The level is more than 3 times the provisional government limit.
Yanagisawa's hospital is located approximately 200km from Fukushima, so the health problems she is seeing that she attributes to radiation exposure causes her to be concerned by what she believes to be a grossly inadequate response from the government.
From her perspective, the only thing the government has done is to, on April 25, raise the acceptable radiation exposure limit for children from 1 mSv/year to 20 mSv/year.
"This has caused controversy, from the medical point of view," Yanagisawa told Al Jazeera. "This is certainly an issue that involves both personal internal exposures as well as low-dose exposures."
Junichi Sato, Greenpeace Japan Executive Director, said: "It is utterly outrageous to raise the exposure levels for children to twenty times the maximum limit for adults."
"The Japanese government cannot simply increase safety limits for the sake of political convenience or to give the impression of normality."
Authoritative current estimates of the health effects of low-dose ionizing radiation are published in the Biological Effects of Ionising Radiation VII (BEIR VII) report from the US National Academy of Sciences.
The report reflects the substantial weight of scientific evidence proving there is no exposure to ionizing radiation that is risk-free.
The BEIR VII estimates that each 1 mSv of radiation is associated with an increased risk of all forms of cancer other than leukemia of about 1-in-10,000; an increased risk of leukemia of about 1-in-100,000; and a 1-in-17,500 increased risk of cancer death.
Dr Helen Caldicott, the founding president of Physicians for Social Responsibility, a group that was awarded the Nobel Peace Prize in 1985, is equally concerned about the health effects from Japan's nuclear disaster.
"Radioactive elements get into the testicles and ovaries, and these cause genetic disease like diabetes, cystic fibrosis, and mental retardation," she told Al Jazeera. "There are 2,600 of these diseases that get into our genes and are passed from generation to generation, forever."
So far, the only cases of acute radiation exposure have involved TEPCO workers at the stricken plant. Lower doses of radiation, particularly for children, are what many in the medical community are most concerned about, according to Dr Yanagisawa.
"Humans are not yet capable of accurately measuring the low dose exposure or internal exposure," she explained, "Arguing 'it is safe because it is not yet scientifically proven [to be unsafe]' would be wrong. That fact is that we are not yet collecting enough information to prove the situations scientifically. If that is the case, we can never say it is safe just by increasing the annual 1mSv level twenty fold."
Her concern is that the new exposure standards by the Japanese government do not take into account differences between adults and children, since children's sensitivity to radiation exposure is several times higher than that of adults.
Al Jazeera contacted Prime Minister Naoto Kan's office for comment on the situation.
Speaking on behalf of the Deputy Cabinet Secretary for Public Relations for the Prime Minister's office, Noriyuki Shikata said that the Japanese government "refers to the ICRP [International Commission on Radiological Protection] recommendation in 2007, which says the reference levels of radiological protection in emergency exposure situations is 20-100 mSv per year. The Government of Japan has set planned evacuation zones and specific spots recommended for evacuation where the radiation levels reach 20 mSv/year, in order to avoid excessive radiation exposure."・・・