SMOKING AND HEALTH.  For centuries the smoking of tobacco in cigarettes, cigars, and pipes has produced controversy over possible health hazards, but only since the 1950’s has sufficient scientific evidence accumulated to make possible a thorough evaluation of the health risk.

吸烟与健康。几个世纪以来，吸食卷烟、雪茄和烟斗中的烟草已经引起了对可能危害健康的争论，但直到20世纪50年代才积累了足够的科学证据使对健康风险的全面评估成为可能。

Scientific investigations of the relationship of smoking and health gained impetus after the beginning of the 20^th century, when an increase in lung cancer was noted. As the use of tobacco increased, studies improved. Although some gaps in knowledge still exist, the information now available is sufficient to permit making sound judgments, based on the converging lines of evidence.

在20世纪之初，当人们注意到肺癌增加时，吸烟与健康关系的科学调查便获得了动力。随着烟草使用的增加，研究得到了改善。尽管在知识方面依然存在着一些差距，但基于积累的证据，现有的信息足以让我们做出合理的判断。

Investigators have directed their principal consideration to cigarette smoking, because the health consequences attributed to it far exceed those due to smoking cigars and pipes. The widespread popularity of cigarettes is comparatively recent in man’s use of tobacco. The smoking pattern began to change at the beginning of the 20^th century. Since then, cigarettes have steadily become more popular than cigars and pipes. In the United States, per capita cigarette consumption—calculated for all persons 15 years of age and older, regardless of whether they smoked---rose from 49 per year in 1900 to 3,888 in 1960. Per capita consumption of cigars, pipe tobacco, and chewing tobacco declined sharply in the same period. Data presented in 1966 indicated a sharp reduction in cigarette smoking in the United States for men under the age of 55 with the trend continuing to 1970. Further increase in cigarette consumption for women of all ages was reported in 1966, but no further increase was noted between 1966 and 1970. However, in 1970 overall per capita cigarette consumption rose. For information on types of tobacco, annual production, and economic matters in the industry, sees TOBACCO.

调查人员将他们的主要考虑指向了吸食卷烟，因为吸食卷烟对健康的影响已远远超过了抽雪茄和烟斗的影响。在人类使用的烟草中，卷烟广泛的流行是相对最近的事。在20世纪初吸烟的模式开始变化。从那时起，卷烟比雪茄和烟斗逐渐变得更受欢迎。在美国，人均卷烟消费量---按所有15岁及以上人士计算，无论他们是否吸过烟---从1900年每年49人增加到1960年的3888人。在同一时期，对雪茄、烟斗以及咀嚼烟草的人均消费量大幅下降。1966年公布的数据表明，美国55岁以下年龄的男性吸卷烟的人数急剧减少，趋势持续到1970年。据报道，1966年各年龄段女性的卷烟消费量进一步增加，但在1966年至1970年间并未发现有进一步增加。然而，在1970年人均消费总量上升了。有关烟草种类，年产量以及该行业经济事宜的信息，请见烟草词条。

 By 1962 the Royal College of Physicians of London reported: “Cigarette smoking is a cause of lung cancer and bronchitis, and various other less common diseases. It delays healing of gastric and duodenal ulcers.” Some scientists, however, EXPRESSED dissenting opinions.

到1962年，伦敦皇家内科医生学院报道：“吸食卷烟是肺癌和支气管炎，以及各种非常见病的一种原因。它延缓了胃和十二指肠溃疡的治愈”。然而，一些科学家表达了异议。

The most widely publicized report in the United States was issued in 1964 by the Surgeon General’s Advisory Committee on Smoking and Health. The principal judgment in the committee’s 150,000-word report was: “Cigarette smoking is a health hazard of sufficient importance in the United States to warrant appropriate remedial action.” The smokers of pipes and cigars were found to incur much less health risk. However, the incidence of cancer and heart disease among them was found to be greater than among nonsmokers.

在美国，最广为人知的是1964年由医疗总监《吸烟与健康》咨询委员会发布的报告。在该委员会15万字的报告中，主要判断是：“在美国，吸食卷烟是一种具有足够严重的健康危害，需要适当的补救措施”。人们发现，烟斗和雪茄的吸食者引发的风险要小得多。然而，在他们当中癌症和心脏病的发病率比不吸烟者更高。

Smoking and Health (1964), the original report to the Surgeon General, had its findings confirmed and its conclusions extended by a review (1967) with two supplements (1968, 1969) and a new report titled The Health consequences of Smoking (1971). For instance, cigarette smoking is now regarded as the most important cause of non-neoplastic bronchopulmonary disease in the United States, whereas the earlier conclusion limited the causal relationship to chronic bronchitis alone. The decrease in life expectancy among young men who smoke two packs of cigarettes a day is now more precisely defined as an average reduction of eight years and an average reduction of four years for those who smoke less than half a pack per day. The relationship of pregnancy and smoking has also been further clarified, new evidence indicating that smoking increases chances of stillbirth, neonatal death, prematurity, and low birth weight.

《吸烟与健康》（1964年），给医疗总监的原始报告，通过一份研究评述（1967年）与两份补充材料（1968年，1969年）和一份题为《吸烟对健康的影响》（1971年）证实了其发现并扩展了结论。例如，吸食卷烟现在被认为是美国非肿瘤性支气管肺病最重要的原因，而早期的结论将因果关系仅限定为慢性支气管炎。在一天吸两包卷烟的年轻男子中预期寿命的减少现在更准确定义为平均减少了8年，而那些每天少于半包的吸烟者平均减少了4年。怀孕与吸烟的关系也进一步澄清，新的证据表明，吸烟增加了死胎、新生儿死亡、早产和低体重儿的可能性。

SCIENTIFIC STUDIES

Areas of Investigation.  Scientific evidence pertaining to the relationship between smoking and Health has been obtained in large part from THREE types of investigations: (1) Animal experiments; (2) clinical and pathological studies; and (3) population studies.

科学研究

调查范围。关于吸烟与健康之间关系的科学证据在很大程度上来自三类调查：（1）动物实验；（2）临床与病理学研究；以及（3）对人群的研究。

In experiments in the laboratory, animals have been exposed to smoke by inhalation and to tars and other smoke components applied directly to their skin or other tissues. Scientists have analyzed the results to see whether such exposure has impaired functions and caused disease in tissues.

在实验室研究中，动物暴露在烟雾中，通过吸入和沾染上焦油，以及直接作用于它们皮肤或其它组织的烟雾成分。科学家对结果进行了分析，想了解这样的接触是否会损害功能，并引起组织的疾病。

For ethical reasons and because of the time involved in producing human disease, studies made directly on man are limited for the most part to observing the consequences of smoking patterns established by the smoker. From these observations, two types of evidence evolve: (1) clinical and pathological studies reflect the damage to body functions, cells, and tissues; (2) population studies of smokers versus nonsmokers by the methods of epidemiology—the science that deals with the incidence of disease in a population—yield valuable statistical data. Since 1939, epidemiological investigations have made important contributions in two forms, the retrospective study and the prospective study.

出于道德原因，也由于引起人类疾病所涉及的时间，直接对人进行的研究在极大程度上仅限于观察吸烟者既定吸烟模式的后果。从这些观察中，逐步发展出两类证据：（1）临床和病理学研究反映了对身体功能、细胞和组织的损害；（2）通过流行病学的方法对吸烟者与非吸烟者人群的研究--研究人群中疾病发病率的科学---产生有价值的统计数据。自1939年以来，流行病学调查在两种形式方面做出了重要贡献，即回顾性研究和前瞻性研究。

A retrospective study looks backward to deal with medical and mortality data from smokers with a specified disease, as compared with appropriate control groups of persons without the disease. For lung cancer alone, 29 retrospective studies had been completed by the mid-1960’s.

回顾性研究回顾处理了有特殊疾病吸烟者的医疗和死亡数据，与没有该疾病的适当对照组的人员进行了对比。仅就肺癌而言，到20世纪60年代，已完成了29例回顾性研究。

The prospective study looks forward. At the start, it records present and past smoking habits of subjects chosen by random selection or from special groups. Then it continues to collect information on these subjects for a period of time, or until they die or are lost from the study. Data from prospective studies permit direct comparison of death rats of smokers and nonsmokers, with or without respect to specific causes of death, and indicate the strength of the association between smoking and specific diseases.

前瞻性研究展望了未来。开始时，通过随机选择或从特殊群组中挑选受试者，记录受试者当下和过去的吸烟习惯。然后，在一段时期内继续收集这些受试者的信息，直到他们去世，或从研究中消失。前瞻性的研究数据允许与吸烟和不吸烟死亡的老鼠进行直接对照，无论是否考虑到死亡的特殊原因，并指出吸烟与特殊疾病之间的关联强度。

COMBINED RESULTS OF SEVEN PROSPECTIVE STUDIES

                            Expected       Recorded     Mortality

                             预期的         记载的      死亡率

Underlying cause of death        deaths         deaths       ratio

潜在的死亡原因               死亡数         死亡数       比率

Cancer of lung …………………………    170.3          1,833        10.8

肺癌

Bronchitis and emphysema …….     89.5            546         6.1

支气管炎和肺气肿

Cancer of larynx ……………………..     14.0            75          5.4

喉癌

Cirrhosis of liver ……………………..     254.0           649         2.6

肝硬化

Coronary artery disease ………….    6,430.7         11,177        1.7

冠状动脉疾病

Other heart diseases ………………      526.0          868          1.7

其它心脏疾病

Hypertensive heart …………………      409.2          631          1.5

高血压

General arteriosclerosis ………….      210.7          310          1.5

一般动脉硬化

 

Death Rates.  The combined results from seven major prospective studies conducted between 1951 and 1959 provide extensive and reliable data comparing the death rates of smokers and nonsmokers. In 1964 the U. S. Surgeon General’s Advisory Committee examined each study separately and declared that it attached “considerable weight to the consistency of findings among the several studies.” Then the committee combined the 7 results to obtain data on 1,123,000 men and 65,023 deaths in 3 countries—Canada, Britain, and the United States. The population groups varied considerably: Canadian war veterans, British doctors, holders of U. S. government life insurance policies, California men in 9 occupations, California members of the American Legion, and 2 groups enrolled by the American Cancer Society—men in 25 states, and men in 9 states.

死亡率。在1951年至1959年间进行的七项主要前瞻性研究的综合结果提供了大量且可靠的数据，对比了吸烟者与非吸烟者的死亡率。1964年，美国医疗总监咨询委员会分别审查了每一项研究，并宣布它附带的“几项研究中调查结果的一致性相当重要”。然后，该委员会综合了7项结果，获得了3个国家---加拿大，英国和美国对1，123，000个男人和65023人死亡的数据。人口组群差别很大：加拿大的退伍军人，英国的医生，美国政府人寿保险单的持有人，加利福尼亚的男性涉及9种职业，加州的美国退伍军人协会成员，以及由美国癌症协会登记的两个群组---25个州的男性，以及9个州的男性。

Among male cigarette smokers, the death rate from all causes was 68% higher than among nonsmokers. Stated another way, for every 100 deaths of nonsmokers during a period of observation, 168 deaths occurred among a similar and comparable group of cigarette smokers; that is, there were 68 excess deaths.

在男性卷烟吸烟者中，各种原因的死亡率比非吸烟者中死亡率高68%。换句话说，观察期内，每100个非吸烟者死亡，在相同和可比较的卷烟吸烟者中就有168名死亡，换言之，死亡多了68人。

Combined results show that death rates among cigarette smokers rise with the number of cigarettes smoked daily. For men who smoke fewer than 10 cigarettes per day, the death rate is 40% higher than for nonsmokers. The death rate is 79% higher for those who smoke from10 to 19 cigarettes per day, 90% higher for those who smoke from 20 to 39 cigarettes per day, and 120% higher for those who smoke more than 40 cigarettes per day. The death rates also grow progressively higher as the years of smoking experience increase. A direct association is also found between the degree of inhalation and the death rate; the more deeply the smoker inhales, the higher the death rate.

综合结果表明，在卷烟吸烟者中的死亡率随着每天吸食卷烟的数量而上升。对于每天吸烟少于10支的人来说，死亡率比不吸烟者高出40%。对那些每天吸10到19支卷烟的人来说，死亡率要高出79%，对那些每天吸20至39支卷烟的人们来说要高出90%，而对每天吸烟超过40支以上的人来说要高出120%。随着吸烟年限的增加，死亡率也会逐渐上升。在吸入程度与死亡率之间也发现了直接的关联；吸烟者吸入的愈深，死亡率就愈高。

Observations on ex-cigarette smokers contribute another finding: the death rate declines dramatically in those who stop smoking. When those who stopped smoking because they were already ill are excluded, the reduction in death rate among ex-cigarette smokers is even more marked.

对戒烟者的观察贡献了另一个发现：在那些停止吸烟的人群中，死亡率明显下降。如果排除那些因已经患病而停止吸烟的人们，戒烟者死亡率的下降就更加明显了。

Less extensive data are available on death rates for smokers of cigars or pipes. For men who smoke fewer than five cigars per day, the death rate remains about the same as for nonsmokers. It rises only slightly among those who smoke more than five cigars per day. The death rate for pipe smokers who smoke 10 or more pipefuls per day is no increased. Even for those who have smoked pipes for more than 30 years, the death rates are only slightly, if at all, higher than for nonsmokers. The difference between death rates for cigarette smokers and smokers of pipes and cigars may be related to the fact that the latter group rarely inhale. In any event, the close association of a large number of excess deaths specifically with cigarettes clearly establishes a grave risk for cigarette smokers.

对雪茄和烟斗吸烟者的死亡率可用的数据较少。对于每天吸少于5支雪茄的人们来说，死亡率大致与不吸烟者的死亡率相同。在那些每天吸多于5支雪茄的人们中，死亡率只是略有上升。对于每天吸10斗或多于10斗的烟斗吸烟者，死亡率并未增加。即使是那些吸烟斗30多年的人，如果有的话，死亡率只是比不吸烟者略微地高一点。对于卷烟吸烟者与烟斗和雪茄吸烟者死亡率之间的差异可能与后者很少吸入的事实有关。无论如何，对烟卷吸烟者来说，特别是与卷烟密切相关的大量过多死亡显然存在着严重风险。

A number of specific diseases are involved in the increased risk of death associated with cigarette smoking. For lung cancer, the death rate among cigarette smokers is almost 1,000% higher than among comparable nonsmokers. For chronic bronchitis and emphysema—over-distensions of air sacs of the lungs—the death rate is 500% higher than for nonsmokers. For coronary heart disease, the death rate stands 70% higher among cigarette smokers. Thus, lung cancer, chronic bronchopulmonary diseases, and coronary heart disease are the causes of death most closely identified with cigarette smoking.

在增加死亡风险中涉及的一些特殊的疾病都与吸食卷烟有关。对肺癌而言，吸食卷烟者的死亡率几乎比可比较的不吸烟者高1000%。对慢性支气管炎和肺气肿而言---肺的气囊过度扩张---死亡率比不吸烟者高500%。对冠状动脉心脏病而言，在吸食卷烟者中会高出70%。因此，肺癌、慢性支气管肺病，以及冠状动脉心脏病都是与吸食卷烟最密切的死亡原因。

If the hazard is measured by the importance of a given disease as a cause of all deaths in the United States, a somewhat different perspective is obtained. Coronary heart disease is the most common variety of fatal heart disease, and heart disease leads the causes of death in the United States. About half of the excess deaths that occur among cigarette smokers are due to coronary heart disease. Lung cancer accounts for less than one fifth of the excess deaths, and all forms of cancer together account for only one fourth of the excess deaths.

如果以某种特定疾病的重要性作为美国所有死亡原因来判定该危害的话，那么就会获得一个稍微不同的视角。冠状动脉心脏病是最常见的各种致命的心脏病，而在美国，心脏病是导致死亡的主要原因。肺癌占额外死亡的不到五分之一，而所有类型的癌症也只占额外死亡的五分之一。

Opposing Theories.  Individual scientists and spokesmen for the tobacco industry have discussed, debated, and challenged the conclusions reached in the studies on the relationship between cigarette smoking and a substantially excessive death rate. One suggestion is that some bias introduced by selection of the subjects for population studies might have influenced the results. However, several studies, conducted independently, using different experimental designs in different countries and on different populations, produced consistent findings. Also, there are no prospective studies that demonstrate an absence of the association between cigarette smoking and the substantially higher death rates known to exist among smokers.

反对的理论。个别科学家和烟草行业的发言人讨论、争论，并对得出的有关吸烟与过高死亡率之间关系的研究结论提出了质疑。一种说法是，人口受试对象选择出现的某些偏差可能影响了结果。然而，在不同的国家，对不同人群，使用不同的实验设计，独立进行的几项研究得出了一致的结论。此外，前瞻性研究并未证明在吸烟者中吸食卷烟与已知存在的高死亡率之间没有关联。

Another suggestion is the possibility that the desire to smoke is inherited, and that those who inherit this desire also inherit a susceptibility to lung cancer and the other widely differing causes of death associated with cigarette smoking. But to explain the tremendous recent increase in lung cancer and at the same time to exonerate cigarette smoking as a causative agent would require the discovery of another cancer-producing factor. The new factor would have to be closely associated with lung cancer and increasingly prevalent throughout the world during the period when lung cancer increased. No such factor has been found. Moreover, two observations make the heredity proposal even more untenable:

另一种说法是，吸烟欲望的可能性是遗传的，而且遗传了这种欲望的那些人也遗传了得肺癌和与吸烟有关的其它各种死亡原因的易感性。但是，要解释近来肺癌的急剧增加，并且同时要免除吸烟作为一种致病因子就需要发现其它致癌的因素。新的因素又不得不与肺癌紧密相关，而且当肺癌增加的这一时期，在全世界都越来越普遍。但并未发现这样的因素。此外，有两项观察使遗传说法更站不住脚：

(1) Ex-cigarette smokers have a lower cancer mortality, and it has been observed that the rate declines in graded steps based on length of discontinuation and amount previously smoked. Such correlations would not be likely if the cigarette smoking had not been at least a determining factor.

（1）戒烟者的癌症死亡率更低，而且据观察，根据中止吸烟的时间长短和以前吸烟的数量，该速率分级降低。如果吸食卷烟不是一种最低限度的决定性因素，那么这种相关性则是不太可能。

(2) Among a religious group that prohibits smoking, the only lung cancer deaths observed in a study occurred in ex-cigarette smokers. It seems unlikely that this religious group, without common physical heritage, would have completely escaped an inherited liability to develop lung cancer if heredity were a dominant factor.

（2）在禁止吸烟的宗教团体中，在研究中唯一观察到的肺癌死亡病例发生在戒烟者中。如果遗传是一种主导因素，那么没有共同身体遗传的宗教团体想要完全避开患肺癌的遗传可能性似乎是不可能的。

Diseases.  It is recognized that a simple cause and effect relationship is unlikely between cigarette smoke and a specific disease, and that the coexistence of several factors is often required for the occurrence of disease. Because these factors vary for each disease, their roles in individual diseases will be considered separately.

疾病。人们认识到，吸食卷烟与特定疾病之间不可能是简单的因果关系，而且疾病的发生通常需要几种因素的共存。因为这些因素因疾病而各不相同，它们在个体疾病中的作用将被分别考虑。

Lung Cancer.  Lung cancer deaths among men have risen at a steady rate since 1930. The lung cancer trend for women, though moving at a slower rate, has been consistently upward. The extraordinary increase in lung cancer has not been observed for cancer of any other part of the body. Preceding and during the period of this rise, there has been a parallel increase in per capita cigarette consumption. It is noteworthy that the disparity between the rate of increase of lung cancer in men and women corresponds in general to differences between smoking habits of men and women, by the amount smoked, and by the duration of smoking. Lung cancer is relatively uncommon among those who do not smoke cigarettes and in those who smoke only cigars or pipes.

肺癌。自1930年以来，肺癌在男性中以一种稳定的速率上升。女性患肺癌的趋势，虽然发展的速度较慢，但一直在上升。在肺癌的惊人增长中并未观察到身体其它部位的癌症。在这种上升之前和期间，人均卷烟消费量已出现了并行的增长。值得注意的是，在男性和女性肺癌增长率之间的明显差异大致相当于男性和女性吸烟习惯之间的差异，由吸烟的数量，以及由吸烟的持续时间而定。在那些不吸卷烟和只吸雪茄或烟斗的人群中相对少见。

Animal experiments show that tars extracted from cigarette smoke regularly induce cancer at the test site when painted on the skin of mice. Lung cancer has been found in dogs exposed to the inhalation of cigarette smoke for two or more years. Under special conditions, lung cancers similar to those in man have also been produced in the lungs of mice, rats, and hamsters by administering polycyclic aromatic hydrocarbons—substances present in cigarette smoke.

动物实验表明，当将卷烟烟雾中提取的焦油涂在老鼠的皮肤上时，在测试的部位会有规律地诱发癌症。在处于吸入卷烟烟雾两年或两年以上环境的狗就会发现已得了肺癌。在特殊条件下，小鼠、大鼠和仓鼠也会因吸入了多环的芬香烃---卷烟烟雾中存在的物质，也会产生与人类相似的肺癌。

The amount of known cancer-producing substances in cigarette smoke is too small to meet the dosage requirements established for the production of skin cancer in animals, and it is likely that other substances, no carcinogenic in themselves, promote cancer production. A number of these substances, called co-carcinogens, have been found in cigarette smoke.

在卷烟烟雾中的已知致癌物质含量太少，无法满足生成动物皮肤癌所需要的剂量，而且很可能是其它物质，本身并不致癌，却促进了癌症的产生。

Several types of abnormal changes in the linings cells (epithelium) of the main airways—the trachea and bronchi—are more common in cigarette smokers than in nonsmokers. The severity of the changes increases with the number of cigarettes smoked and decreases after the discontinuation of cigarette smoking. The importance of the changes rests mainly on the belief that advanced hyperplasia, with many atypical cells, immediately precedes the development of cancer.

在主呼吸道衬里细胞（上皮细胞）中几种类型的异变---气管和支气管---在卷烟吸烟者中比不吸烟者更常见。变化的严重性随着吸食卷烟的数量而增加，并在中止吸食卷烟后而减少。变化的重要性主要取决于这样的信念，即具有许多非典型性细胞的晚期增生，总会在癌症演变之前。

The 29 retrospective studies of groups of persons with lung cancer and of control subjects without lung cancer uniformly show an association between cigarette smoking and lung cancer. More heavy smokers are found among lung cancer patients. The relative risk of lung cancer ranges from 2.4 times greater for light smokers to 34.1 times greater for heavy smokers. The average male smoker incurs tenfold greater risk of developing lung cancer than the nonsmoker. All seven prospective studies show remarkable consistency in the higher death rates of cigarette smokers form lung cancer. The risk of developing lung cancer increases with the duration of smoking and the degree of inhalation and is decreased by discontinuing smoking.

肺癌群组与非肺癌对照组的29项回顾性研究一致显示，在吸食卷烟与肺癌之间存在着关联。发现在肺癌患者中更多的是烟瘾很大的人。轻度吸烟者的肺癌相对风险大于2.4倍，而重度吸烟者的相对风险大于34.1倍。平均起来男性吸烟者比不吸烟者患肺癌的风险高出十倍。所有七项前瞻性研究表明，吸食卷烟者形成更高的肺癌死亡率具有显著的一致性。患肺癌的风险随着吸烟的持续时间和吸入程度而增加，也会因中止吸烟而减少。

A causal relationship between cigarette smoking and lung cancer does not exclude the operation of other factors. Not all types of lung cancer are associated with cigarette smoking. Some lung cancer cases—less than 10%--occur among those who do not smoke cigarettes. The adenocarcinomas of the lung, which start in glandular linings, apparently have little relationship to smoking. Viruses may be involved in the causation of lung cancer and could be a determinant—a reason why some heavy smokers develop lung cancer while many do not.

吸食卷烟与肺癌的因果关系并不排斥其它因素的运行。不是所有类型的肺癌都与吸食卷烟有关。一些肺癌病例---少于10%---出现在那些并不吸烟的人群中。发生在腺衬里的肺腺癌明显与吸烟没什么关系。病毒可能是涉及肺癌的原因，而且可能是一个决定性因素---这就是为什么一些烟瘾大的人得了肺癌，而许多人却没有得的原因。

Occupational studies have demonstrated an increased death rate from lung cancer associated with several types of mining exposure, but unfortunately the contribution of cigarette smoking was not evaluated. In view of the relatively small size of the population exposed to industrial carcinogens, it is unlikely that such agents alone could account for the increasing lung cancer risk in the general population.

一些与职业有关的研究证明，肺癌死亡率的增加与几种类型的采矿暴露有关，但遗憾的是，吸食卷烟的促成作用却未得到评估。鉴于处于工业致癌环境的人口数量相对较少，因此，指望这类介质就能单独解释普通人群中肺癌风险增加的原因是不大可能的。

Air pollution also may contribute causally to lung cancer. In Britain, where the death rate from lung cancer is the highest in the world, the higher levels of air pollution may be a factor in addition to cigarette smoking. Yet in countries such as Iceland, where air pollution is almost nonexistent, the correlation of cigarette smoking and lung cancer is well established.

空气污染也可能导致肺癌。在英国，那里的肺癌死亡率是世界最高的，除了吸食卷烟外，更严重的空气污染可能是一个因素。然而，在诸如冰岛这样的国家，那里几乎没有什么空气污染，吸食卷烟与肺癌的关联性已得到充分证实。

In summary, experimental, clinical-pathological, and epidemiological evidence indicates that cigarette smoking is the main cause of lung cancer in men. Cigarette smoking is also a cause of lung cancer in women, but accounts for fewer cases than in men. The risk of developing lung cancer increases with the number of cigarettes smoked per day and the duration of smoking, and it diminishes with cessation of smoking. Cigarette smoking appears to be much more important than other factors, such as air pollution, in the causation of lung cancer in the general population. The lung cancer risk for pipe and cigar smokers appears to be only slightly greater than for the nonsmoker, and it is clearly much less than for cigarette smokers.

总之，实验、临床病理学和流行病学的证据表明，吸食卷烟是男性肺癌的主要原因。吸食卷烟也是女性肺癌的一种原因，但比重要比男性的更少。患肺癌的风险随着每天吸食卷烟的数量和吸烟的持续时间而增加，并随着停止吸烟而减少。吸食卷烟似乎比其它因素重要的多，例如在普通人肺癌原因中的空气污染。烟斗和雪茄吸烟者的肺癌风险似乎比不吸烟者只多了一点，而比卷烟吸食者显然要少得多。

Other cancer Sites.  On the basis of evidence similar to that presented for lung cancer, cigarette smoking is considered a major factor in causing cancer of the larynx. An association also appears to exist between tobacco use and cancer of the esophagus, although the evidence is more limited. An interesting association between cigarette smoking and cancer in a distant site, the urinary bladder, is under investigation. Smoking is a significant factor in the development of oral cancer, and pipe smoking, alone or with other tobacco use, is causally related to lip cancer.

其它部位的癌症。根据癌症所呈现的类似证据，吸食卷烟被认为是引发喉癌的主要因素。在吸烟与食道癌之间似乎也存在着关联，尽管证据很有限。在吸食卷烟与远处部位膀胱癌之间有趣的关联正在被研究。在口腔癌的发展中，吸烟是一种重要因素，而吸烟斗，单独或吸食其它烟草与唇癌存在着因果关系。

(待续)

CHARLES LE MAISTRE

                  Chancellor, The University of Texas System Member,

              Surgeon General’s Advisory Committee on Smoking and Health

                              查尔斯·李·梅斯特

                           校长，德克萨斯大学系统成员，

医疗总监《吸烟与健康》咨询委员会

 

                                         2023年7月3日译

（译者注：该词条部分位列《大美百科全书》1985年版，第25卷，第70页至73页）