Radiation and Human Health輻射與人體健康
1．Radioactivity occurs naturally. The main sources are in space, rocks, soil, water and even the human body itself. This is called background radiation and levels vary from place to place, though the average dose is fairly constant. The radiation which is of most concern is artificial radiation which results from human activities. Sources of this include the medical use of radioactive materials, fallout and contamination from nuclear industry, and the storage and dumping of radioactive waste.
1、輻射在自然界中普遍存在。主要的輻射源存在于空間、巖石、土壤、水、甚至是人體之中。這叫做背景輻射。輻射強(qiáng)度會(huì)因地點(diǎn)而異，但平均輻射量實(shí)則大致相同。最令人擔(dān)憂的是人類活動(dòng)造成的人工輻射。輻射源包括醫(yī)用放射性材料、核工業(yè)的放射性沉降物和污染物，以及輻射廢棄物的積存和傾倒。
2.While artificial radiation accounts for a small proportion of the total, its effects can be disproportionate. Some of the radioactive materials discharged by human activities are not found in nature, such as plutonium, while others which are found naturally may be discharged in different physical and chemical forms, allowing them to spread more readily into the food-chain.
2、雖然人工輻射只占輻射總量的一小部分，其后果卻很嚴(yán)重。人類活動(dòng)所排放的一些放射性物質(zhì)本在自然界中無處可尋，比如說钚。然而另外一些本來天然存在的物質(zhì)卻以各種不同的物理或化學(xué)形式被釋放出來，致使它們能更輕易地進(jìn)入食物鏈。
3.For all these reasons, simple comparisons of background and artificial radioactivity may not reflect the relative hazards. Equally important, it has never been shown that there is such a thing as a safe dose of radiation and so the fact that we are progressively raising global levels should be of as much concern to us as the possibility of another major nuclear test, nuclear reactor or shipment of plutonium means an additional and unnecessary health risk.
3、基于這些原因，也許僅僅拿背景輻射和人工輻射作簡單比較并不能夠反映相關(guān)的危險(xiǎn)性。同樣重要的是，從來也沒有過輻射存在安全攝入量這種說法。因此，就像處理另一場大型核試驗(yàn)、核反應(yīng)堆的制造、钚材料的運(yùn)送等環(huán)節(jié)會(huì)對(duì)健康形成潛在威脅一樣，不斷増加輻射總量也應(yīng)該引起我們足夠的重視。
4.In general, the effects of radiation can be divided into those which affect the individuals exposed and those which affect their descendants. Somatic effects are those which appear in the irradiated or exposed individual. These include cancer and leukaemia. Hereditary or genetic effects are those which arise in subsequent generations.
4、總的來說，輻射的危害可以分為對(duì)輻射接收者本人的影響以及對(duì)其子孫后代的影響。身體傷害尤見于輻射接受者本身，包括癌癥和白血病這類病癥。遺傳影響則發(fā)生在其后代身上。
5.Many of the elements which our bodies need are produced by the nuclear industry as radioactive isotopes or variants. Some of these are released into the environment, for example iodine and carbon, two common elements used by our bodies. Our bodies do not know the difference between an element which is needed and which is not. So radioactive elements can be absorbed into living tissues, bones or the blood, where they continue to give off radiation. Radioactive strontium behaves like calcium—an essential ingredient in our bones—in our bodies. Strontium deposits in the bones send radioactivity into the bone marrow, where the blood cells are formed, causing leukemia.
5、我們身體所需要的許多元素是由核工業(yè)以放射性同位素或者是變體的形式排放出來的。其中有一些被釋放到環(huán)境中，比如說碘和碳，這是我們身體所需的兩種常見元素。我們的身體并不知道需要哪種元素，不需要哪種元素。所以放射性元素能夠被我們的活細(xì)胞組織、骨骼和血液吸收，而進(jìn)入人體后其輻射并未停止。放射性元素鍶在我們體內(nèi)和人體骨骼必需元素鈣表現(xiàn)類似。鍶在骨骼中沉積并且將放射能傳遞至產(chǎn)生血液細(xì)胞的骨髓之中，從而引發(fā)白血病。
6.There are three principal effects which radiation can have on cells: firstly cells may be killed; secondly the way cells multiply may be affected, resulting in the cells of the ovaries or testes, leading to the development of a child with an inherited abnormality.
6、輻射可以對(duì)細(xì)胞產(chǎn)生三大主要影響：第一，細(xì)胞可能會(huì)被殺死；第二，細(xì)胞的繁殖可能會(huì)受影響，進(jìn)而影響到卵巢或睪丸中的細(xì)胞，引起先天性胎兒畸形。