社説：食品の放射能 説明と測定を徹底せよ

(Mainichi Japan) October 29, 2011
Gov't should thoroughly explain health risks from internal radiation exposure through food
社説：食品の放射能　説明と測定を徹底せよ

The Japanese government is required to thoroughly explain health risks from overall radiation exposure to the public and ensure that food products are measured for radiation now that the Food Safety Commission (FSC) has shown its safety standards on internal radiation exposure through foods.
　食品から受ける内部被ばくの影響を検討してきた食品安全委員会が、評価書をまとめ厚生労働省に答申した。

In a report it submitted to the Health, Labor and Welfare Ministry on Oct. 28, the FSC explained that if lifetime cumulative exposure to radiation exceeds roughly 100 millisieverts, excluding natural radiation, it will adversely affect human health.
「自然放射線などを除いた生涯の累積線量が、おおよそ１００ミリシーベルトを超えると健康に影響がある」という内容だ。

Based on that report, the ministry will set upper limits on radiation for each type of food product.
　この評価を基に厚労省が食品ごとの新たな規制値を決めるが、

The problem is the interpretation of the 100 millisievert upper limit.
わかりにくいのはこの１００ミリシーベルトの位置づけだ。

When it released an initial draft of the report in July, the FSC explained that 100 millisieverts refers to the upper limit on the total amount of overall radiation exposure, both internal and external.
　７月に評価案が示された時には、「外部被ばくと内部被ばくを合わせた線量」と説明された。

However, the report submitted to the ministry limits it to internal exposure through food.
ところが、答申では「食品から受ける内部被ばく」に限定された。

The report has raised questions as to whether the upper limit on internal radiation exposure through food should remain at 100 millisieverts or should be lowered if the amount of external radiation exposure is high.
　では、外部被ばくが高くても食品の基準は１００ミリシーベルトなのか、それともその分低いのか。

The FSC has declined to answer this question on the grounds that the Health, Labor and Welfare Ministry or other government organizations in charge should decide on the matter.
食品安全委は「厚労省などしかるべき管理機関が考えること」として判断を避けた。

The FSC apparently believes that it should stick to its mission of evaluating risks involving food.
　食品安全委の使命は食品のリスク評価をすることだという理屈だが、

However, the government should stop such sectionalism and evaluate risks of overall radiation exposure as what members of the public want to know is how their health is affected by both internal and external radiation exposure.
１人の人は内部被ばくと外部被ばくの影響をあわせて受ける。知りたいのは全体の影響だ。政府は、こうした縦割りをやめ、被ばく全体のリスク評価をすべきではないか。

The current regulations on food safety set the upper limit on exposure to radioactive cesium at 5 millisieverts per year.
　現在の食品の規制値は放射性セシウムによる被ばく線量の上限を年５ミリシーベルトとしている。

However, since this is a provisional limit set following the accident at the tsunami-hit Fukushima No. 1 Nuclear Power Plant, it is an urgent task for the Health, Labor and Welfare Ministry to set stricter standards.
これはあくまで事故直後の暫定値であり、厚労省はより厳しい新基準を早急に決める必要がある。

In doing so, the ministry should thoroughly explain the basis for the new standards, including health risks involving external radiation exposure and internal exposure to less than 100 millisieverts, in an effort to convince the public.
その際には、国民が納得できるよう、外部被ばくや１００ミリシーベルト以下の影響まで含めた基準値の根拠についてよく説明してもらいたい。

The FSC report suggests that children are more vulnerable to radiation than adults.
　答申は、子どもの方が放射線に対する感受性が大人より高い可能性があることも指摘した。

However, as it is unrealistic to set separate upper limits for children and adults, it is necessary to set a figure that can protect the health of children as the upper limit on all citizens.
食品の規制値を大人と子どもで分けることは現実的ではなく、子どもに合わせた規制が必要になる。

But even if a stricter upper limit is set, it alone cannot eliminate consumers' anxieties as long as they do not know how much radiation they have been exposed to through food.
　ただ、規制値が新たに決まっても、実際に食品からどれだけ被ばくしているかがわからなければ、消費者の不安は解消されない。

Sample surveys on food that national and local governments are currently conducting are far from sufficient.
国や自治体が実施しているサンプル調査だけでは不十分だ。

In order to protect the health of citizens and relieve their concerns and mental stress, central and local governments should conduct more thorough and detailed measurements of radiation contained in food.
　健康を守り、不安やストレスを減らすために、もっときめ細かい測定を進めてほしい。

Such measurements should cover a wider diversity of food products, as fish and other marine products could later turn out to be contaminated with radiation as a result of bioaccumulation.
今後、生物濃縮によって魚介類などの汚染が新たにわかってくる可能性もあり、幅広く実施すべきだ。

University of Tokyo professor Ryugo Hayano has proposed that the amount of radioactive cesium contained in school lunches should be measured and that the results be released on a daily basis.
　東大の早野龍五教授は実際に子どもたちが食べる給食１食分の放射性セシウムの量を測り数値を毎日公表することを提案している。

Tatsuhiko Kodama, professor at the same university, has suggested that all food products should be measured for radiation using belt-conveyer-style measurement devices.
同大の児玉龍彦教授は米袋などをそのまま測るベルトコンベヤー式の計測機器による全品検査を提案している。

A growing number of retailers and citizens are voluntarily measuring food products for radiation.
流通業界や市民が食品を独自に計測する動きも出てきている。

The national and local government should actively support these moves.
　政府や自治体にはこうした動きも後押ししてもらいたい。

If the current situation continues, consumers' concerns about food safety cannot be eliminated even if the actual radiation levels remain low.
このままでは、たとえ現実の線量が低くても、消費者の不安は収まらない。

毎日新聞　2011年10月29日　2時30分