October 25, 2012 (508) 289-3340 Japan’s “triple disaster,” as it has become known, began on March 11, 2011, and remains unprecedented in its scope and complexity. To understand the lingering effects and potential public health implications of that chain of events, scientists are turning to a diverse and widespread sentinel in the world’s ocean: fish. Events on March 11 began with a magnitude 9.0 earthquake, the fourth largest ever recorded. The earthquake in turn spawned a massive 40-foot tsunami that inundated the northeast Japanese coast and resulted in an estimated 20,000 missing or dead. Finally, the wave caused catastrophic damage to the Fukushima Dai-ichi nuclear power plant, resulting in the largest accidental release of radiation to the ocean in history, 80 percent of which ended up in the Northwest Pacific Ocean. In a Perspectives article appearing in October 26, 2012, issue of the journalScience, WHOI marine chemist Ken Buesseler analyzed data made publicly available by the Japanese Ministry of Agriculture, Forestry and Fisheries (MAFF) on radiation levels in fish, shellfish and seaweed collected at ports and inland sites in and around Fukushima Prefecture. The picture he draws from the nearly 9,000 samples describes the complex interplay between radionuclides released from Fukushima and the marine environment. In it, Buesseler shows that the vast majority of fish caught off the northeast coast of Japan remain below limits for seafood consumption, even though the Japanese government tightened those limits in April 2012. Nevertheless, he also finds that the most highly contaminated fish continue to be caught off the coast of Fukushima Prefecture, as could be expected, and that demersal, or bottom-dwelling fish, consistently show the highest level of contamination by a radioactive isotope of cesium from the damaged nuclear power plant. He also points out that levels of contamination in almost all classifications of fish are not declining, although not all types of fish are showing the same levels, and some are not showing any appreciable contamination. As a result, Buesseler concludes that there may be a continuing source of radionuclides into the ocean, either in the form of low-level leaks from the reactor site itself or contaminated sediment on the seafloor. In addition, the varying levels of contamination across fish types points to complex methods of uptake and release by different species, making the task of regulation and of communicating the reasons behind decision-making to the fish-hungry Japanese public all the more difficult. “To predict the how patterns of contamination will change over time will take more than just studies of fish,” said Buesseler, who led an international research cruise in 2011 to study the spread of radionuclides from Fukushima. “What we really need is a better understanding of the sources and sinks of cesium and other radionuclides that continue to drive what we’re seeing in the ocean off Fukushima.” To help achieve this, Buesseler and his colleague Mitsuo Uematsu at the University of Tokyo are organizing a scientific symposium in Tokyo on November 12 and 13 to present the most current findings available about how radionuclides from Fukushima Dai-ichi have affected the ocean, marine life, seafood, policy decisions, and media coverage to date. The event will also include a free public colloquium in Tokyo on November 14 to help spread information about the lessons learned to the broadest possible audience. This work was supported by the Gordon and Betty Moore Foundation. The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the ocean and its interaction with the Earth as a whole, and to communicate a basic understanding of the ocean’s role in the changing global environment.

http://www.whoi.edu/page.do?pid=7545&tid=3622&cid=153749

水俣病の原因となった水銀の使用や輸出入などを国際的に規制する新たな条約の制定に向けてスイスで開かれている国連の会議で、日本時間の１９日に条文が決まり、名称は水俣病の教訓を生かしたいとして「水俣条約」に決まりました。

世界の水銀を巡っては、途上国を中心に環境汚染や健康被害が問題となっていて、３年前から水銀の使用や輸出入を規制する新たな国際条約について議論が始まり、今月１３日にスイスのジュネーブで始まった国連の会議で、条文の合意に向けて協議を続けてきました。 会議は最終日の１８日ではまとまらず、延長して議論を続けてきましたが、日本時間の１９日午後に条約の内容が決まりました。 合 意された条文には、▽最終処分する目的など一部を除いて水銀の輸出入を禁止することや、▽水銀が使用されている一部の電池や蛍光灯などの製造や輸出入を ２０２０年までに禁止すること、それに▽新規の鉱山からの水銀の産出を禁止し、既存の鉱山についても条約の発効から１５年後までに禁止することなどが盛り 込まれました。 また条約の前文には、「水俣病を教訓にして水銀を適正に管理し、将来にわたって二度と同じ問題を引き起こさない」という文言が盛り込まれました。 条 約を巡って日本政府は、水俣病の教訓を忘れないために、名称を「水俣条約」にしたいと提案していて、１９日の会合でも、「水俣病と同じような健康被害や環 境破壊を世界のいずれの国でも繰り返さない、という決意を各国で共有するという意味を込めて、この条約が『水俣条約』と名付けられることを望みます」と述 べました。 条約の名称を巡っては、一部の患者団体から「被害者の救済が終わっていないのに条約名にするのはおかしい」として、反対する声が上がっていましたが、各国が全会一致で了承し、条約名は「水俣条約」に決まりました。 水俣条約はことし１０月、熊本市と水俣市で開かれる会議で採択される予定です。

厚生労働科学研究費補助金による測定結果

http://www.mhlw.go.jp/stf/houdou/2r98520000023p4a-att/2r98520000023pas.pdf