A few data on smoking and health 1, in China at present tobacco-induced deaths, chronic lung disease accounted for 45%, lung cancer accounted for 15%, esophageal cancer, stomach cancer, liver cancer, stroke, ischemic heart disease and tuberculosis accounted for 5% to 8% each. Li Hui, Department of Thoracic Surgery, Chaoyang Hospital, Beijing, China 2. Tobacco-related deaths currently account for 13% of deaths in men (and may eventually account for about 33%), but only 3% in women (and may eventually account for about 1%), because the proportion of smokers among young women has been reduced to very low levels. 3. 2/3 of men currently smoke before age 25, few quit, and about half of those who continue to smoke will die prematurely in middle and old age. 4, If current smoking patterns continue, 300 million Chinese men who are now 0.29 years old will eventually have 100 million premature deaths due to smoking. 5, in 1990, tobacco caused 600,000 deaths, by 2000 will reach 800,000 (700,000 men), according to the current smoking pattern, by the middle of the 21st century, there will be about 3 million deaths per year from tobacco. Second, China faces the hazards of tobacco A retrospective proportional mortality study of 1 million deaths found that among male smokers aged 35 to 69 years, excess deaths from tumors were 5l%, excess deaths from respiratory disease 31%, and excess deaths from vascular disease 15%. All three of these excess deaths were significant (P<;0.0001). In smoking men aged 70 years and older, excess deaths were 54% for neoplasms, 15% for respiratory disease, and 6% for vascular disease. Although fewer women smoked, the attributable risk of lung cancer and respiratory disease in smoking women was similar to that in men. Although, lung cancer mortality rates for both men and women aged 35-69 years who smoked were approximately three times higher than those for nonsmokers, the absolute number of excess deaths from lung cancer due to smoking varied greatly among regions in China because of the large differences in lung cancer mortality rates among nonsmokers in different regions. In 1990, tobacco caused about 600,000 deaths in China (500,000 men), and by 2000, this number will increase to 800,000 (400,000 people aged 35-69) or more. Thus, it is concluded that, based on the current age-specific mortality rates of smokers and nonsmokers, 1 in 4 smokers will die from tobacco, and this ratio will approximately double as the epidemic progresses. If current smoking rates in China (about 2/3 of men smoke) continue, 100 million of the 300 million men now aged 0-29 years will die prematurely from smoking, half of them in middle age and half in old age. However, although the overall risk of death from tobacco in China is as great as that of smokers in Western countries, the specific situation in China is significantly different. Tobacco causes more deaths from chronic lung disease than from vascular disease in China. The health risks of tobacco are already enormous, and they are not limited to China. By the beginning of the next century, tobacco will cause about 4 million deaths per year globally, 50/50 between rich and poor countries. If current smoking conditions continue, by about 2030, 10 million people will die each year from smoking, with 70% of these deaths occurring in developing countries. Third, smoking and lung cancer in 16,317 cases of men who died of lung cancer in one city, 82%; (13440) smoked before 1980, while the reference group of 30,790 deaths in 60% of men; (18544) smoking, suggesting that the risk of death from lung cancer in urban smokers is about three times greater than in non-smokers, seen in rural men similar to urban. Although the number of lung cancer deaths among men aged 35-69 years varied widely by region, with only 80 cases (Xi'an) and 2961 cases (Shanghai), the relative risk of lung cancer was extremely consistent across regions (including rural areas) and was within the distribution range of 2.0-4.0. The age-adjusted relative risk for lung cancer in women was similar to that in men. Forty-two percent of urban lung cancer deaths; smoked, compared with 15% of the reference group; smoked. The risk of lung cancer death among urban smoking females (as among the same urban males) was at least approximately three times that of non-smokers. Among rural women, the age-adjusted relative risk was 1.98. Lung cancer mortality rates among nonsmokers in different cities varied widely, by as much as 10-fold, with the exception of the cold northeastern regions (Harbin, Jilin, Changchun, and Shenyang), where lung cancer mortality rates were all high due to long-term exposure to indoor soot and cooking fumes pollution, but the geographic distribution of lung cancer was not regular, regardless of the background lung cancer Regardless of the level of background lung cancer mortality in each region, the lung cancer mortality rate among male and female smokers was approximately three times that of nonsmokers. Combining all cities, the lung cancer mortality rate was 0.5/1000 for nonsmokers (0.52 for men and 0.42 for women) and 1.3/1000 for smokers (1.54 for men and 1.35 for women, accounting for 12% of the total number of deaths among urban smokers of that age;). The absolute lung cancer mortality rate in rural areas is only half of that in urban areas, which may be partly related to the larger proportion of missed diagnoses in late middle age. Four types of cancer deaths in China, lung, esophageal, gastric, and liver cancers, accounted for approximately 70% of the total, and the risk of death from all four types of cancer was significantly higher in smokers than in nonsmokers. The relative risk of lung cancer for men aged 35-69 years nationwide was 2.72, suggesting that half (52.3%) of lung cancer deaths in the population were directly related to smoking. The relative risk for esophageal cancer was 1.61, stomach cancer was 1.35, liver cancer was 1.40, and the other five "minor" site cancers (oral cavity, pharynx, pancreas, and bladder) combined were 1.51. Combining all other tumors also showed some correlation with smoking (relative risk of 1.24). Thus, when all tumors are combined, the total relative risk is 1.51 (0.02) and the proportion of smoking-attributable deaths is 24.4% (18.7% in the older age group). It is suggested that about 1/4 of cancer deaths in middle-aged men could be avoided if they did not smoke The absolute mortality rate among nonsmokers can differ by a factor of 2 in terms of tumor mortality, but in most regions smokers have an approximately 50% higher all-tumor mortality rate than nonsmokers. Lung cancer deaths account for about half of all-tumor excess deaths among smokers. Fourth, deaths attributable to tobacco According to estimates, the number of deaths attributable to tobacco in China in 1990 was 600,000 (500,000 for men and 100,000 for women, 300,000 for those aged 35-69 and 300,000 for those aged 70 and older). Of these deaths, 300,000 were due to respiratory diseases, 200,000 to neoplasms, and 100,000 to vascular diseases. The number of annual adult deaths in China is expected to rise from 7 million in 1990 to 9 million in 2000, mainly due to population increase. Thus, even if the percentage of deaths attributable to tobacco does not increase further, the absolute number of smoking deaths will still increase to 800,000 by the year 2000. However, the expected increase in the percentage of deaths attributable to tobacco will further increase the number of deaths, so that by the first decade of the next century, smoking-related deaths in China will likely reach about 1 million per year. The majority of tobacco-related deaths are from tumors and respiratory diseases. Mortality from these diseases is positively correlated with the amount and duration of daily smoking, and based on the results of this and other previous studies, it can be concluded that tobacco is an important cause of most or all of the excess deaths from neoplasms and respiratory diseases among smokers. Increased causality and probability: The so-called smoking causes a disease implies an increased probability of premature death due to smoking. Many smokers do not develop lung cancer (thus, smoking is not a "sufficient cause" of lung cancer), some nonsmokers do develop lung cancer (thus, smoking is not a "necessary cause" of lung cancer), but many smokers who develop lung cancer would not have developed lung cancer if they had not smoked (Thus, smoking is a major cause of lung cancer)'. Of course not smoking does not prevent death (because eventually everyone dies), but smoking causes early death, and those who die from smoking between the ages of 35 and 69 lose about 20 to 25 years of life. The main way that smoking kills people in China is by increasing the prevalence of diseases that are already fairly common. Lung cancer or chronic obstructive pulmonary disease (COPD) accounts for about 60% of deaths attributable to tobacco. Almost all of the remaining deaths are due to six other diseases, each accounting for 5 to 8 percent (esophageal cancer, stomach cancer, liver cancer, tuberculosis, stroke, and ischemic heart disease). In China, the relative risk of these 8 diseases is lower than in the United Kingdom or the United States, but the background mortality rate (excluding ischemic heart disease) is much higher among Chinese nonsmokers, so the absolute excess risk due to tobacco is still very large among both male and female smokers. V. Tobacco's contribution to current mortality The all-cause mortality risk for urban males who start smoking around age 20 is 1.35 times higher than for nonsmokers, and if this relative risk remains constant across all ages, this means that 1 in 4 smokers who start smoking around age 20 will eventually die prematurely due to smoking (0.35/1.35). The corresponding rate in rural areas is 1 in 5 men. In addition, the relative risk for men must have increased slightly since 1987. Thus, based on current (1990s) mortality rates for nonsmokers and for those who started smoking in their 20s, 1 in 4 smokers nationwide will die prematurely from smoking. This is confirmed by national prospective studies. Recent studies in countries such as the United States and the United Kingdom have shown that about half of all persistent cigarette smokers will eventually die from tobacco (1/4 at age 35-69 and 1/4 at age 70 and older). In contrast, studies in these countries early in the tobacco hazard epidemic suggested that only about 1 in 4 smokers died from tobacco. Similarly, studies of mortality in China in 1987 must have greatly underestimated the harm of tobacco to future middle-aged and older adults because few of the study subjects were heavy cigarette smokers from an early age. The full effects of the massive increase in cigarette consumption in China between the 1950s and 1970s, and the even larger increase from 500 billion cigarettes in 1980 to 1,800 billion in 1990, will not be evident for several years. This increase is primarily due to both the increase in cigarette consumption per smoker and the increase in the proportion of smokers in the population, both of which will significantly increase the risk per smoker. The dramatic changes in cigarette consumption over the past few decades will double the risk of death from tobacco for at least 1 in 4 current smokers. Thus, about half of the Chinese young adults who are currently persistent smokers will eventually die prematurely as a result of their smoking habit. From a public health perspective, if current smoking patterns continue, it is not the number of deaths caused by smoking in this decade or the next that will be greatly affected, but rather the number of deaths in subsequent decades. Although it is difficult to make precise predictions about deaths from a specific disease, more reliable predictions can be made about overall patterns, and there will be large differences in the extent of future smoking harms between men and women based on current smoking rates.