1、On March 11, 2011, a magnitude 9.0 earthquake struck Japan, causing a devastating tsunami that tore through the coastal regions and leveled the villages in its path. The earthquake also severely damaged nuclear reactors at the Fukushima Daiichi Power Plant, sparking explosions and the release of rad

2、ioactive material. Recent reports suggest that leaks from the reactors core may be extremely dangerous, not only threatening workers there but also contaminating the facility and surrounding community on the longer term. As Japanese engineers, scientists, and firefighters work to control the continu

3、ing crisis at the vulnerable Fukushima plant - efforts that are hindered by strong aftershock earthquakes - fears about the scope of this nuclear disaster and the radiations health effects continue to spread. Radiation is energy that is transmitted in the form of waves or particles. Ionizing radiati

4、on describes waves or particles that have enough energy to remove electrons from other atoms, thus creating chemically reactive ions (charged atoms) that can damage cells.2011年3月11日,日本發(fā)生9.0級地震,造成毀滅性的海嘯,橫掃了沿海地區(qū),摧毀了村莊的道路。地震還嚴(yán)重受損福島第一核電站核反應(yīng)堆,引發(fā)爆炸和放射性物質(zhì)的釋放。最近的報(bào)告表明,從反應(yīng)堆泄漏的核心可能是極其危險(xiǎn)的,不僅威脅工人,但也污染的設(shè)施和周圍社區(qū)。日本

5、工程師,科學(xué)家,和消防員工作控制持續(xù)脆弱的福島核電站危機(jī)努力強(qiáng)余震地震受阻的擔(dān)憂這場核災(zāi)難和天然氣的范圍輻射的健康影響繼續(xù)傳播。輻射是能量波或粒子的形式傳播。電離輻射描述波或粒子,有足夠的精力去把電子從其他原子,從而創(chuàng)建化學(xué)活性離子(帶電原子),會損傷細(xì)胞。In the Fukushima plant, several types of radioactive particles have been released into the air. Chief among these are iodine-131, cesium-137, plutonium-239, and strontium-

6、90, each of which decays at a different rate and can have various effects on the body. Iodine-131 has a half-life of 8 days - meaning that it is half as radioactive after 8 days, thus making its effects relatively short-lived. Exposure to iodine-131 can cause thyroid cancer. With half-lives of 30 an

7、d 29 years, respectively, cesium-137 and strontium-90 both stay in the environment for longer periods of time. Cesium-137 can travel through the food chain in milk or vegetables and can increase the risk of various cancers; strontium-90 is absorbed into bones and teeth and can increase the risk of l

8、eukemia or bone cancer. Plutonium-239 is toxic if inhaled.Though the word radiation sounds menacing, in fact humans are exposed to naturally occurring radiation every day from the sun, cosmic rays, the soil, and other sources. People are exposed on average to 3 mSv (milli-sieverts, or one-thousandth

9、 of a sievert) per year. A sievert is the most common unit by which scientists measure the biological risk of radiation exposure, because it takes into account both the amount of radiation absorbed (measured in Gy (Gray) or rad (radiation absorbed dose) as well as the intensity of ionization in the

10、affected living cells.在福島核電站,幾種類型的放射性粒子被釋放到空氣中。其中最主要的是碘- 131,銫- 137、钚- 239和鍶- 90,其中每個(gè)衰變速度,可以有各種不同的對身體的影響。碘- 131的半衰期為8天,這意味著它是一半放射性8天后,從而使其影響相對較短。接觸碘- 131可能導(dǎo)致甲狀腺癌。半衰期為30和29年,分別銫- 137和鍶- 90環(huán)境中呆的時(shí)間更長。銫- 137可以通過食物鏈在牛奶和蔬菜,可以增加患各種癌癥的風(fēng)險(xiǎn);鍶- 90被吸收進(jìn)骨骼和牙齒,可以增加白血病的風(fēng)險(xiǎn)或骨癌。如果吸入钚- 239是有毒的。雖然“輻射”這個(gè)詞聽起來威脅,事實(shí)上人類每天都暴露在

11、天然輻射來自太陽,宇宙射線,土壤,和其他來源。人們接觸平均為3毫西弗(milli-sieverts或1000西韋特)。西韋特是最常見的單元,科學(xué)家測量生物輻射暴露的風(fēng)險(xiǎn),因?yàn)樗紤]輻射吸收的量(以Gy(灰色)或rad(輻射吸收劑量)以及電離輻射的強(qiáng)度受影響的活細(xì)胞。Many commonly used medical procedures contribute to a persons average radiation exposure. To get a sense of the magnitude of 3 mSv, consider this: a typical mammogram

12、delivers 0.13 mSv per test; a chest x-ray delivers 0.1 mSv; and a routine dental x-ray delivers 0.04 to 0.15 mSv. Individually, these are minimal exposures; however, medical professionals must take care to limit their exposures (e.g. by walking out of the room) over the course of testing many patien

13、ts everyday. The health effects of radiation are cumulative, so higher doses at one time, or lower doses delivered over longer periods of time, can compromise human health.What is considered a harmful dose of radiation? Estimates vary depending on the duration and strength of the exposure. Below is

14、a chart produced by the Environmental Protection Agency (EPA) on health effects and exposure. Depending on the strength of the radiation, an exposed person may also experience burns or other symptoms of acute radiation syndrome (ARS). A one-time dose of 4 sieverts or more can be fatal.To protect the

15、 health of nuclear power plant workers, the Japanese government has set 250 mSv as the maximum amount of exposure to radiation at any one time. Estimates of the radiation emitted by the Fukushima plant in Japan have ranged from a high of 1,000 mSv per hour (1 Sv per hour) inside the plant to 400 mSv

16、 per hour, 11.9 mSv per hour, and below , with levels dropping off sharply the farther away from the plant they are measured. So far, several people working to contain the damage from the nuclear plant to bring the situation under control have been exposed to high levels of radiation, including a fe

17、w who were hospitalized after stepping in puddles of water at the facility that contained highly concentrated levels of radiation. Several people are currently hospitalized.很多常用的醫(yī)療過程導(dǎo)致一個(gè)人的平均輻射。為了了解3毫西弗的大小,考慮一下:一個(gè)典型的乳房x光檢查提供了0.13毫西弗/測試;x光胸透了0.1毫西弗,和常規(guī)的牙科x光單獨(dú)提供0.04到0.15毫西弗。,這是最小的風(fēng)險(xiǎn);然而,醫(yī)務(wù)人員必須小心限制他們的風(fēng)險(xiǎn)(

18、如步行走出房間)每天在測試的過程中許多病人。輻射對健康的影響是累積的,所以高劑量,或低劑量隨著時(shí)間的流逝,可能影響人類健康。有害劑量的輻射是什么?估計(jì)取決于暴露的持續(xù)時(shí)間和強(qiáng)度。下面是一個(gè)圖表由美國環(huán)境保護(hù)署(EPA)對健康的影響和風(fēng)險(xiǎn)。根據(jù)輻射的強(qiáng)度不同,接觸的人也可能經(jīng)歷燒傷或其他急性輻射綜合癥的癥狀(ARS)。一次性輻射劑量的4或更多的可能是致命的。保護(hù)核電站工人的健康,日本政府設(shè)置250毫西弗的最大數(shù)量在任何一次輻射。估計(jì)在日本福島核電站輻射的范圍從每小時(shí)1000毫西弗每小時(shí)(1 Sv)在工廠每小時(shí)400毫西弗,每小時(shí)11.9毫西弗,和下面,與水平急劇下降遠(yuǎn)離工廠測量。到目前為止,幾個(gè)

19、人努力遏制破壞核電站控制局勢已經(jīng)暴露于高水平的輻射,包括幾個(gè)住院后踩坑里的水設(shè)施,包含高度集中的輻射水平。有幾個(gè)人正在住院治療。A person may be exposed to elevated levels of radiation by breathing in radioactive particles, ingesting them through exposed food or drink, or coming into close bodily contact with a source of radiation.Different types of radiation wil

20、l produce different health effects, based on the half-life of the particle (how long it takes to lose half its radioactivity, a measure of how fast it degrades) and the way it interacts with the body. Iodine-131, plutonium-239, cesium-137, and strontium-90 are the four most harmful radioactive eleme

21、nts involved in the Japanese nuclear disaster, with half-lives of 8 days, 24,000 years, 30 years, and 29 years, respectively. With the exception of iodine-131 which has a short half life, whatever amounts of these other elements are released are likely to stay in the environment and pose a threat to

22、 human, plant, and animal life for several years to come. Cesium-137 can deposit itself in milk and vegetables, increasing the risk of several forms of cancer for those that ingest enough of significantly contaminated foods.一個(gè)人可能會暴露在高濃度的輻射吸入放射性粒子,攝入通過接觸食物或飲料,或進(jìn)入親密的身體接觸輻射的來源。不同類型的輻射會產(chǎn)生不同的健康影響,基于粒子的半衰

23、期(要多長時(shí)間失去一半的放射性,衡量它的降解速度)以及它與人體相互作用的方式。碘- 131、钚- 239,銫- 137,和鍶- 90四個(gè)最有害放射性元素參與日本核災(zāi)難,半衰期8天,24000年,30年,29年,分別,除了碘- 131的半衰期很短,無論數(shù)量的這些其他元素釋放可能在環(huán)境和威脅人類,植物和動物生活好幾年。銫- 137可以存款在牛奶和蔬菜,增加一些癌癥的風(fēng)險(xiǎn)對于那些攝取足夠的明顯污染食物。Exposure to high doses of radiation can lead to a broad range of acute health problems which are usu

24、ally only experienced by individuals close to the source of radiation such as reactor workers. One of the possible acute effects of exposure to high levels of radiation over a small period of time is Acute Radiation Syndrome (ARS) or radiation sickness. For an exposed individual to develop ARS, the

25、radiation must be penetrating and cover the whole body. The radiation doses that lead to ARS hover around 1 sievert - about 300 times the average annual dose (3 millisieverts) of background radiation. ARS is associated with damage to the bone marrow, and at higher doses (10Sv) other organs may be af

26、fected.Symptoms of ARS include nausea, weakness, diarrhea, headaches, fever, hair loss, skin damage, diminished organ functions and possible seizures and coma. Following the Chernobyl nuclear disaster, approximately 134 plant workers and firefighters received doses of 700 to 13,400 mSv and developed

27、 ARS. Of the 134 ARS patients, 28 died. Exposure to high levels of gamma radiation in particular can contribute to a broad range of acute health effects. For example, gamma doses of 2Gy, 10Gy and 20Gy can lead to hemopoietic syndrome, gastrointestinal syndrome and central nervous system problems, re

28、spectively. Other acute health problems that can result from high exposure to radiation include premature aging, male sterility, birth defects, and possible death.暴露于高劑量的輻射會導(dǎo)致廣泛的急性健康問題通常只經(jīng)歷了由個(gè)人接近反應(yīng)堆輻射的來源,如工人。一個(gè)可能的急性暴露于高水平的輻射的影響在一小段時(shí)間內(nèi)是急性輻射綜合癥(ARS)或輻射病。暴露個(gè)人發(fā)展農(nóng)業(yè)研究所,輻射必須滲透和覆蓋整個(gè)身體。輻射劑量導(dǎo)致ARS徘徊在1西韋特年均300倍劑量(3毫西弗)的背景輻射。ARS與骨髓損害有關(guān),和高劑量( 10 sv)其他器官可能會受到影響。ARS的癥狀包括惡心、弱點(diǎn)、腹瀉、頭痛、發(fā)熱、脫發(fā),皮膚損傷,減少器官功能和可能的痙攣和昏迷。切爾諾貝利核災(zāi)難后,大約134名工廠工人和消防員收到劑量的700到13400毫西弗和發(fā)達(dá)的農(nóng)業(yè)研究所。134年農(nóng)業(yè)研究所的病人,28日死了。特別是暴露于高水平的伽馬輻射可以導(dǎo)致廣泛的急性健康影響。例如,射線劑量的2 gy,gy