简报：核泄漏如何威胁人类健康.docVIP

。Briefing: How nuclear accidents damage human health 15:25 15 March 2011 by Debora MacKenzie For similar stories, visit the Energy and Fuels , The Nuclear Age and Cancer Topic Guides Read more: Special report: After Japans megaquake The Japanese authorities have announced that radiation levels surrounding the Fukushima Daiichi nuclear power plant are increasing to potentially harmful levels. New Scientist investigates the health risks associated with nuclear power plant explosions How do nuclear accidents impact health? Apart from the damage caused by fires and explosions, accidents also release radioactive materials which can cause radiation sickness. Radiation exposure above a certain threshold, usually only received by workers and emergency teams in a stricken plant, causes acute radiation syndrome within hours of exposure. Depending on the dose of radiation this ranges from skin rashes, vomiting and diarrhoea, to coma and death. Radiation damages DNA, especially as it assembles in dividing cells. That means tissues which contain many dividing cells, such as the gut lining, skin and bone marrow, are most at risk of damage. High enough doses also damage brain cells and such doses are invariably fatal. Less severe damage can be treated, however. Gut damage disturbs fluid balance and can lead to blood infection; marrow damage means no blood cells are produced for clotting and fighting infection. If those problems can be managed, people can be kept alive long enough for gut and marrow to regenerate. A cloned human hormone that boosts white blood cell production sometimes helps; there is little else. Fears of nuclear terrorism have recently inspired more funding for research into new treatments, most aiming to limit cell death in damaged tissues. What radioactive elements are being released at the Fukushima Daiichi nuclear power plant? As nuclear cores melt down, reacting nuclear fuel creates many different radioactive elements, all with different toxic effects. R