© flickr & Xelcise
米国では，福島第一原発の事故による放射性物質の飛散の影響について懸念が高まった。米国環境保護庁（EPA）とエネルギー省（DOE）は18日，EPA，DOEいずれの計測システムでも懸念するような放射能の上昇は国内で検出されず，カリフォルニア州とワシントン州で16～17日に微量の放射性同位体が検出されたが，これらからの放射能は自然の放射線源から人々が受ける1日量の10万分の1であるとした。1986年のチェルノブイリの事故後には，自然に人々が受ける放射能の年間量の1000分の1未満に当たる放射性同位体が検出されたという。（吉田素子）
JOINT EPA/DOE STATEMENT: Radiation Monitors Confirm That No Radiation Levels of Concern Have Reached the United States
The United States Government has an extensive network of radiation monitors around the country and no radiation levels of concern have been detected. The U.S. Environmental Protection Agency RadNet system is designed to protect the public by notifying scientists, in near real time, of elevated levels of radiation so they can determine whether protective action is required. The EPA’s system has not detected any radiation levels of concern.
In addition to EPA’s RadNet system, the U.S. Department of Energy has radiation monitoring equipment at research facilities around the country, which have also not detected any radiation levels of concern.
As part of the Comprehensive Nuclear Test Ban Treaty Organization’s International Monitoring System (IMS), the Department of Energy also maintains the capability to detect tiny quantities of radioisotopes that might indicate an underground nuclear test on the other side of the world. These detectors are extremely sensitive and can detect minute amounts of radioactive materials.
Today, one of the monitoring stations in Sacramento, California that feeds into the IMS detected miniscule quantities of iodine isotopes and other radioactive particles that pose no health concern at the detected levels. Collectively, these levels amount to a level of approximately 0.0002 disintegrations per second per cubic meter of air (0.2 mBq/m3). Specifically, the level of Iodine-131 was 0.165 mBq/m3, the level of Iodine-132 was measured at 0.03 mBq/m3, the level of Tellurium-132 was measured at 0.04 mBq/m3, and the level of Cesium-137 was measured at 0.002 mBq/m3.
［単語和訳］
EPA：米国環境保護庁（Environmental Protection Agencyの略） DOE：米国エネルギー省（Department of Energyの略） Radiation Monitors：放射線モニター Radiation Levels：放射能レベル ～of Concern：懸念される～
Extensive：広範囲に及ぶ have been detected：検出された RadNet：EPAの放射能モニタリングの全国的ネットワークの名称 notifying～of...：～に...を知らせること in near real time：ほとんど即時に elevated：上昇した protective：保護する
facilities：施設
Comprehensive Nuclear Test Ban Treaty Organization：包括的核実験禁止条約機関 capability：能力 radioisotopes：放射性同位体 detectors：検出器 minute amounts of：微量の radioactive materials：放射性物質
feeds into：～に情報を送り込む miniscule：極めて少ない iodine isotopes：ヨウ素同位体 particles：粒子 pose concern：懸念をもたらす Collectively：総合して amount to：総計～になる approximately：約 disintegrations per second：壊変毎秒（= ベクレル，放射能の単位） cubic meter：立方メートル mBq：ミリベクレル Specifically：具体的には Iodine-131：ヨウ素131 Iodine-132：ヨウ素132 Tellurium-132：テルル132 Cesium-137：セシウム137
