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  3. Radiance Exists EverywhereA)Do you believe, as I used t

Radiance Exists EverywhereA)Do you believe, as I used t

游客2024-04-22  5
问题                         Radiance Exists Everywhere
A)Do you believe, as I used to, that radioactivity is very rare and very dangerous, restricted to arsenals and power plants? Let’ s take a look at your kitchen. The bananas are radioactive from their potassium, the Brazil nuts have a thousand times more radium than any other food item, and your dried herbs and spices were irradiated to counter bacteria, germination and spoilage. There’s thorium in your microwave oven and americium in your smoke detector.
B)Elsewhere in the house, cat litter, cigarettes, adobe, granite and brick are all actively radiating you. Always and forever, radiation is both raining down on you from the skies—striking mile-high Denver two to three times as powerfully as San Diego— and floating up at you from our bedrock’ s decaying uranium. Those all-natural mineral waters you soaked in on that spa vacation? Did the brochure mention that hot springs are hot in two senses, as the heat emanates from those same uranium combustions?
C)Radiance is so pervasive that geologists have uncovered evidence of 14 naturally occurring nuclear reactors. It’s coming out of the walls of the U.S. Capitol in Washington and New York’s Grand Central Terminal. Your cat is radioactive, your dog is radioactive, your friends and your family are all radioactive, and so, as it turns out, are you. Right now your body is emanating radiant effluvia and, every time you and another human being get together, you irradiate each other.
D)By the way, do you live in the continental U.S.? In 1997, the National Cancer Institute reported that the Cold War detonations at the Nevada Test Site had polluted nearly the whole of the country with drifting airborne radioactive iodine, creating somewhere between 10,000 and 75,000 cases of childhood thyroid cancer.
E)The Centres for Disease Control and Prevention estimated that of the nearly 600,000 Americans dying of cancer every year, 11,000 will be because of those tests. All those decades worrying about the Soviet Union attack Americans with nuclear weapons? Instead, while Washington irradiated Americans from Nevada, Moscow irradiated its own citizens with tests from Kazakhstan.
F)But there is, in all this, some good news. The source of radioactivity is an atom so obese that it defies the laws of attraction gluing together our material world and spits out little pieces of itself—two kinds of particles and a stream of gamma rays, similar to X-rays. An overdose of gamma rays is like a vicious sunburn, with skin damage and elevated cancer risks, but those particles are too big to penetrate our skin, meaning that they need to be swallowed or inhaled to wreak damage.
G)Remember the movie "Silkwood", with Meryl Streep writhing in naked agony as men with brushes scrubbed her in the shower? They were washing away her exposure. The truly fearful event in a nuclear accident, then, isn’t fallout but meltdown, where the core burns through the floor and suffuses the water table. There it causes agricultural mayhem and radioactive dust that you better not breathe.
H)The good news, though, is in that word: overdose. We’re not dropping dead en masse from radiation poisoning or its ensuing cancers on a daily basis because, like all poisons, it isn’t the particular atom that will get you. It’s the dose. And damage from radioactivity requires a much greater dose than any of us would have believed.
I)This upheaval in everything we thought we knew comes from two decades long studies. The United Nations spent 25 years investigating the Chernobyl disaster and determined that 57 people died during the accident itself(including 28 emergency workers), while 18 children living nearby died in the following years of thyroid cancer from drinking the milk of tainted cows.(Thyroid cancer is very curable, so their deaths could have been prevented by an effective public-health service, but Ukraine’s and Belarus’ s collapsed alongside the Soviet Union’ s.)In short, the most terrifying nuclear disaster in human history, which spread a cloud the size of 400 Hiroshimas across the whole of Europe, killed 75 people.
J)Some believe that this number is too conservative, but those beliefs aren ’t backed by data. One critic is physicist Bernard Cohen, who predicted, "The sum of exposures to people all over the world will eventually, after about 50 years, reach 60 billion millirems, enough to cause about 16,000 deaths." To give this number perspective, around 16,000 Americans die every year from the pollution of coal-burning power plants.
K)Besides the U.N.’s Chernobyl report, the most extensive data on human exposure to radiation is the American-Japanese joint study of hibakusha— "explosion-affected persons"—the 200,000 survivors of Hiroshima and Nagasaki. The expectations at the start of that study(which has taken over 60 years and continues to this day)were that survivors would be overrun with tumours and leukaemia and that a percentage of their descendants would be genetically deformed. Instead, researcher Evan Douple concluded, "The risk of cancer is quite low, lower than what the public might expect."
L)Radiologist John Moulder analyzed the results of one group of 50,000 survivors, about 5,000 of whom had developed cancer: "Based on what we know of the rest of the Japanese population, you would have expected about 4,500 of them. So we have 5,000 cancers over 50 years where we would expect 4,500." Assuming that the 500 additional cases are all due to radiation, and that means a rate of 1%. And there was no increase in inherited mutations. Remember: These aren’ t victims of a power plant breakdown; they are survivors of a nuclear attack.
M)For the Fukushima disaster of 2011, the consensus estimate is a 1% increase in cancer for employees who worked at the site and an undetectable increase for the plant’s neighbours. Just think of the difference between the overwhelming nuclear fears and nightmares we’ ve all suffered from since 1945 and that range of increased risk: 0% to 1%. And if that’s not enough to question everything you thought you knew about radiation, consider that, even after the catastrophe in Japan, the likelihood of work-related death and injury for nuclear plant workers is lower than for real estate agents ... and for stockbrokers.
N)Here’s the truth about you and radiation: There’s no reason to worry about power-plant meltdowns or airport scanners, where the X-rays have been replaced by millimetre wave machines. And don’ t worry about those radioactive everyday items. By scientific measures, the average American gets 620 millirems of radiation each year, half from background exposure, and that number needs to reach 100,000 to be worrisome.
O)Instead of fretting about these things, have your basement tested for radon. Monitor how many nuclear diagnostics and treatments, from X-rays to CT scans, you and your family get. Use sunscreen. And follow the advice of the woman who defined "radioactivity", Marie Curie: "Now is the time to understand more, so that we fear less." [br] 840 millirems of radiation each year is within the safe domain.
选项
答案 N
解析 每年840毫仑的辐射量属于安全范围。根据关键词“millirems”可定位至N段末句“By scientific measures．the average American gets 620 millirems of radiation each year，half from background exposure，and that number needs to reach 1 00，000 to beworrisome．”，题干是对该句的改写，因此，题干出自N段。
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