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背景与问题在有毒物质对人体健康引起的危害中,癌已成为首先受注意的问题。此外,急性中毒(如脑与神经受铅与汞的毒害)、突变、先天性缺陷及其他健康危害也受到政府的关注。由于癌的发病率高,一般是不可康复的,对它的了解又很缺乏,患病后经常是很痛苦的,因此癌这一疾病特别受到群众的重视。此外,很多致癌物质同样也具有毒性效应。一、癌的发病率在增加异常的组织细胞无节制地生长则形成癌。当前在美国的全部死因中,癌仅次于心血管疾病而居第二位,每年约死亡400,000人。如仅以55岁以下的人进行统计,则癌的死亡率高于心血管疾病。1900年时癌占死
Background and Problems Cancer has become the first area of concern among the hazards that toxic substances cause to human health. In addition, acute poisoning (such as the brain and nerve being poisoned by lead and mercury), mutations, congenital defects and other health hazards are also of concern to the government. Because of the high incidence of cancer, it is generally not rehabilitated, and its lack of understanding, often after suffering is very painful, so the cancer is particularly the disease by the masses attention. In addition, many carcinogens also have a toxic effect. First, the incidence of cancer in the abnormal increase in abnormal growth of tissue cells is the formation of cancer. Of all the current causes of death in the United States, cancer ranks second only to cardiovascular disease, with about 400,000 deaths each year. If only people under the age of 55 statistics, the cancer mortality rate is higher than cardiovascular disease. When cancer accounted for death in 1900