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  3. The food irradiation process is a simple one. The new US plant, Vindicator o

The food irradiation process is a simple one. The new US plant, Vindicator o

游客2024-02-19  5
问题     The food irradiation process is a simple one. The new US plant, Vindicator of Florida Incorporated in Mulberry, Fla. , uses a material called cobalt (钴) 60 to irradiate food. Cobalt 60 is radioactive isotope (同位素) (form) of the metallic element cobalt. Cobalt 60, which gives off radiation in the form of gamma rays, is also used for radiation therapy for cancer patients and for sterilizing (消毒) hospital equipment. The radioactive isotope is created by bombarding cobalt with subatomic particles in a nuclear reactor. However, irradiation plants do not themselves contain nuclear reactors.
    In the irradiation plant, food is exposed to thin rods of cobalt 60. The rods give off gamma rays, which disrupt chemical processes in contaminating organisms. The disruption breaks down the cell walls of organisms or destroys their genetic material. The dose, set by the US Food and Drug Administration (FDA), is enough to kill organisms on food, but not enough to produce significant changes in the food itself.
    Although irradiation slightly decreases the nutritive value of foods, the loss is less than that produced by some other methods of food preservation. Canning, for example, results in a much greater loss of nutrients.
    Those who object to irradiation say that the process may create substances not found in non-irradiated food. Since the 1960’s researchers have studied irradiated food at microscopic levels to try to find such substances, called unique radiolytic (辐射分解) products. After reviewing these studies, the FDA determined that compounds formed during irradiation were similar to substance found in non-irradiated foods and were not dangerous to consume.
    Destruction of microorganisms that cause illness is an important goal of irradiation. About 250 million cases of food poisoning or 1 per person — occur every year in the US, according to FDA estimates. Food poisoning can cause vomiting (呕吐), diarrhea (腹泻), fever, headache — and, occasionally, death.
    Because of the apparent safety of food irradiation, and the problems presented by contaminated food, scientific groups — including the American Medical Association, the World Health Organization, and the United Nations Food and Agriculture Association — have voiced nearly universal support for the process. Worldwide, 38 nations have approved irradiation for 355 products.
    Like microwave ovens, food irradiation has aroused apprehension and misunderstanding. Yet it has been scrutinized (审查) more thoroughly than other methods of food treatment that we have come to regard as safe, and it appears to be a method whose time has come. [br] With cases of food poisoning increasing,______.
选项 A、food irradiation should be carried out with care
B、it is more urgent to irradiate foods
C、medical researches into treatment of the diseased should be strengthened
D、Americans are beginning to accept food irradiation
答案 B
解析 可定位在第6段，指出因为辐照食物消毒法明显安全而被污染食物导致诸多问题，因而包括世界卫生组织在内的众多科学组织一致声称支持这一过程，而选项B中的urgent(急迫的)与文中voiced nearly universal support for意义相近，故正确选项为B。
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