19. Smoking and Cancer.
19、吸烟和癌.
1. Americans smoke six thousand million cigarettes every year (1970 figures). This is roughly the equivalent of 4,195 cigarettes a year for every person in the country of 18 years of age or more. It is estimated that 51% of American men smoke compared with 34% of American women.
1、美国人每年抽烟60亿支(1970年的统计数字)。这大致等于每个18岁以上的人一年要吸4195支烟。据估计，美国有51%的男性吸烟，而女性吸烟的比例则为34%。
2. Since 1939, numerous scientific studies have been conducted to determine whether smoking is a health hazard. The trend of the evidence has been consistent and indicates that there is a serious health risk. Research teams have conducted studies that show beyond all reasonable doubt that tobacco smoking, particularly cigarette smoking, is associated with shortened life expectancy.
2、1939年以来，为了确定抽烟是否有害健康进行了大量的科学研究。证据所显示的趋势是一贯的，并表明对人体的健康有严重的危险。许多研究小组进行的研究不容置疑地表明，吸食烟草，特别是吸卷烟与预期寿命缩短有关。
3. Cigarette smoking is believed by most research workers in this field to be an important factor in the development of cancer of the lungs and cancer of the throat and is believed to be related to cancer of the bladder and the oral cavity. Male cigarette Smokers have a higher death rate from heart disease than non-smoking males. (Female smokers are thought to be less affected because they do not breathe in the smoke so deeply.) The majority of doctors and researchers consider these relationships proved to their satisfaction and say, "Give up smoking. If you don't smoke—don't start!"
3、这方面的研究人员大都相信吸卷烟是产生肺癌、喉癌的重要因素，还认为膀胱癌、口腔癌也与此有关。男性吸烟者的心脏病死亡率比不吸烟的高。(他们认为女性吸烟者受影响小一些，因为她们吸烟不那么深。)大多数医生和研究人员认为，上述那些关系已得到令人满意的证实，并且告诫说：“戒烟吧，如果你不会抽—那可不要学!”
4. Some competent physicians and research workers—though their small number is decreased even further—are less sure of the effect of cigarette smoking on health. They consider the increase in respiratory diseases and various forms of cancer may possibly be explained by other factors in the complex human environment —atmospheric pollution, increased nervous stress, chemical substances in processed food, or chemical pesticides that are now being used by farmers in vast quantities to destroy insects and small animals. Smokers who develop cancer or lung diseases, they say, may also, by coincidence, live in industrial areas, or eat more canned food. Gradually, however, research is isolating all other possible factors and proving them to be statistically irrelevant.
4、有些精通业务的医生和研究人员—虽然这些人不多，并且人数在进一步减少—不那么肯定吸卷烟对人体健康有影响。他们认为呼吸系统疾病和各种癌症的增多也许可以说是由于人类复杂环境中另外一些因素，即：空气的污染、人们精神压力的增大、经过加工的食品中的化学物质、或化学杀虫药引起的。农民现在大量使用这些农药杀死昆虫和小动物。据他们说，那些患了癌症或肺病的人可能恰巧也住在工业区，或是吃了更多的罐头食品。但是研究工作逐渐排除了其它因素的可能性，并且用统计数字证明这些因素是无关的。
5. Apart from the scientific statistics, it might be helpful to look at what smoking tobacco actually does to the human body. Smoke is a mixture of gases, vaporized chemicals, minute particles of ash, and other solids. There is also nicotine, which is a powerful poison, and black tar. As the smoke is breathed in, all these components form deposits on the membranes of the lungs. One point of concentration is where the air tube, or bronchus, divides. Most lung cancer begins at this point.
5、除了科学统计之外，研究工作还有助于认清吸食烟草对人体的实际影响。抽烟产生的烟雾是一种混合的气体，包括气化的化学物质，极小的灰末微粒和其它固体，还有毒性很强的尼古丁和黑焦油。当吸进烟时，所有这些成分就都沉淀在肺膜上。在气管和支气管分支的地方有一个集中点。大部分肺癌就从这里发端。
6. Smoking also affects the heart and blood vessels. It is known to be related to Beurger's disease, a narrowing of the small veins in the hands and feet that can cause great pain and lead even to amputation of limbs. Smokers also die much more often from heart disease.
6、抽烟也影响心脏和血管。现已查明抽烟与伯尔格氏病有关。这种疾病使手脚的细静脉不断缩小，从而引起剧烈疼痛甚至会导致截肢。抽烟者死于心脏病的也比不吸烟的人多得多。
7. While all tobacco smoking affects life and expectancy and health, cigarette smoking appears to have a much greater effect than cigar or pipe smoking. However, nicotine consumption is not diminished by the latter forms, and current research indicates a causal relationship between all forms of smoking and cancer of the mouth and throat. Filters and low tar tobacco are claimed to make smoking to some extent safer, but they can only marginally reduce, not eliminate the hazards.
7、尽管吸食各种烟草都会影响预期寿命和健康，但是抽香烟的影响要比抽雪茄和抽烟斗大得多。不过，后两种并不能减少对尼古丁的吸食，并且当编者注：本篇文章写作日期较早。事实上，近年来美国吸烟人口比率以及吸烟量一直在持续下降。根据美国疾病预防与控制中心的报告，2003年美国抽烟人口比率已经下降到21、6%。美国对吸烟有明确的法律规定：未满21周岁的人不得吸烟；在公共场所，如图书馆、教堂、超市、饭店、公共汽车、地铁等处不得吸烟。美国对烟草行业的征税特别重，故烟价很高，这也是限制吸烟的重要措施。前的研究指出各式各样的吸烟都和口腔癌、喉癌有某种因果关系。据称过滤嘴香烟和低焦油烟草能使吸烟在某种程度上比较安全，但是这只能略微减少危害，而不能消除危害。