2017年职称英语模拟题-2017年中石油职称英语新版选读文章系列(37)

Radiation and Human Health辐射与人体健康

　　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、辐射在自然界中普遍存在。主要的辐射源存在于空间、岩石、土壤、水、甚至是人体之中。这叫做背景辐射。辐射强度会因地点而异，但平均辐射量实则大致相同。最令人担忧的是人类活动造成的人工辐射。辐射源包括医用放射性材料、核工业的放射性沉降物和污染物，以及辐射废弃物的积存和倾倒。

　　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、虽然人工辐射只占辐射总量的一小部分，其后果却很严重。人类活动所排放的一些放射性物质本在自然界中无处可寻，比如说钚。然而另外一些本来天然存在的物质却以各种不同的物理或化学形式被释放出来，致使它们能更轻易地进入食物链。

　　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、基于这些原因，也许仅仅拿背景辐射和人工辐射作简单比较并不能够反映相关的危险性。同样重要的是，从来也没有过辐射存在安全摄入量这种说法。因此，就像处理另一场大型核试验、核反应堆的制造、钚材料的运送等环节会对健康形成潜在威胁一样，不断増加辐射总量也应该引起我们足够的重视。

　　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、总的来说，辐射的危害可以分为对辐射接收者本人的影响以及对其子孙后代的影响。身体伤害尤见于辐射接受者本身，包括癌症和白血病这类病症。遗传影响则发生在其后代身上。

　　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、我们身体所需要的许多元素是由核工业以放射性同位素或者是变体的形式排放出来的。其中有一些被释放到环境中，比如说碘和碳，这是我们身体所需的两种常见元素。我们的身体并不知道需要哪种元素，不需要哪种元素。所以放射性元素能够被我们的活细胞组织、骨骼和血液吸收，而进入人体后其辐射并未停止。放射性元素锶在我们体内和人体骨骼必需元素钙表现类似。锶在骨骼中沉积并且将放射能传递至产生血液细胞的骨髓之中，从而引发白血病。

　　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、辐射可以对细胞产生三大主要影响：第一，细胞可能会被杀死;第二，细胞的繁殖可能会受影响，进而影响到卵巢或睾丸中的细胞，引起先天性胎儿畸形。

　　7.In most cases, cell death only becomes significant when large numbers of cells are killed, and the effects of cell death therefore only become apparent at comparatively high dose levels. If a damaged cell is able to survive a radiation dose, the effects of the cell damage may never become apparent. A few malfunctioning cells will not significantly affect an organ where the large majority are still behaving normally.

　　7、在多数情况下，只有当大量细胞被杀死时，细胞死亡才会引起严重后果。因此细胞死亡这一问题只有在辐射量相对较大的情况下才得以凸显。如果一个受损细胞在接触一定量的辐射后存活下来，那么细胞受损的危害就不易被察觉。当大多数细胞在器官内正常运作时，个别构造细胞受损并不会对整个器官产生重大影响。

　　8.However, if the affected cell is a germ cell within the ovaries or testes, the situation is different. Ionizing radiation can damage DNA, the molecule which acts as the cell's "instruction book". If that germ cell later forms a child, all of the child's cell will carry the same defect. The localized chemical alteration of DNA in a single cell may be expressed as an inherited abnormality in one or many future generations.

　　8、然而，如果受损细胞是卵巢或者睾丸中的生殖细胞，情况就不容乐观了。电离辐射可以破坏在细胞中充当着“指令书”作用的DNA。如果受损的生殖细胞之后发育形成了胎儿，那么这个孩子体内所有的细胞都会带有同样的缺陷。单个细胞中DNA的局部化学成分的改变将会在未来一代或者几代人身上以畸形的方式表现出来。

　　9.In the same way that a somatic cell in a body tissue is changed in such a way that it or its descendants escape the control processes which normally control cell replication, the group of cells formed may continue to have a selective advantage in growth over surrounding tissues. It may ultimately increase sufficiently in size to form a detectable cancer and in some cases cause death by spreading locally or to other parts of the body.

　　9、在身体组织中的体细胞通过逃脱控制细胞复制方式的复制程序来使体细胞自身或者后代发生改变，而新形成的细胞群体在增殖过程中以同样的方式来获得一种优于其周围组织的选择性优势。最终它们可能在数量上急剧增加，从而形成一种可检测性的癌症。在某些情况下，这些细胞的局部扩散或者扩散到身体的其他部位还会导致死亡。

　　10.While there is now broad agreement about the effects of high-level radiation, they are complicated by the length of time it takes for effects to show up and the fact that the populations being studied (bomb survivors, people exposed to nuclear industry) are small and exact doses are hard to calculate.

　　10、虽然关于髙能辐射的危害性如今已达成广泛共识，但由于辐射伤害往往要很长时间才得以显现，而且可供研究的对象(爆炸幸存者、接触核工业的人群)人数很少，而且他们体内的辐射量很难被精确测算，这些都使问题变得更加复杂。

　　11.All that can be said is that predictions made about the effects of a given dose vary. A growing number of scientists point to evidence that there is a disproportionately high risk from low doses of radiation. Others assume a directly proportionate link between the received doses and the risk of cancer for all levels of doses, while there are some who claim that at low doses there is a disproportionately low level of risk.

　　11、我们只能说，人们关于特定辐射量对人体影响程度的猜测层出不穷且各不相同。越来越多的科学家们指证说明，少量辐射会给身体带来难以想象的危害。另一些人则认为不管辐射是多是少，人体受到的辐射量和癌症患病风险之间都存在着某种直接的比例关系。但是也有一些人声称辐射少则危害小。

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