(71) (72) (78) (74) (75) (76) Vos-Brat, C., RuMKE, P. Immunoglobulin concentrations, PHA reac- tions of lymphocytes zm vitro, and certain antibody titers of healthy smokers. Jaarboek Karkeronderzoek Kankerbestruding 19: 49-53, 1969. Weary, P. E., Woop, B. T. Allergic contact dermatitis from tobacco smoke residues. Journal of the American Medical Association 208(10): 1905-1906, June 9, 1969. Westcort, F. H., Wricut, I. S. Tebacco allergy and thromboangiitis obliterans. Journal of Allergy 9: 555-564, 1938. YEAGER, H., JR. Alveolar cells: Depressant effect of cigarette smoke on protein synthesis. IN: Proceedings of the Society for Experimental Biology and Medicine 131: 247-250, December 26, 1968. _ ZUSSMAN, B. M. Atopic symptoms caused by tobacco hypersensitivity. Southern Medical Journal 61(11): 1175-1179, November 1968. ZuSSMAN, B. M. Tobacco sensitivity in the allergic patient, Annals of Allergy 28(8) : 371-377, August 1970. Chapter 9 Tobacco Amblyopia Source: 1971 Report, Chaprer 7, pages 431 - 438. 527 Summary and conclusions References ............. Contents 529 TOBACCO AMBLYOPIA Tobacco amblyopia (tobacco-aleohol amblyopia) is that syn- drome of visual failure occurring in association with the use of tobacco, with or without the concurrent use of alcohol, and with or without concurrent nutritional deficits. The disease has a subacute onset, leading to a loss of visual acuity and color perception (12). It is characterized by centrocecal scotomas which are bilateral but not necessarily symmetrical and which have sloping diffuse edges and by the presence of nuclei of denser visual loss within the large scotomas (22, 23). Such visual impairment is not unique to tobacco amblyopia, as it is also seen in neurodegenerative disorders, such as Leber’s hereditary optic atrophy (7, 25). Clinical information on tobacco amblyopia has appeared in nu- merous articles throughout the past century. This information has been reviewed by Silvette, et al. (17) and, more recently, by Dunphy (5). Pure tobacco amblyopia (TA), that is amblyopia unassociated with excessive alcohol intake or the exposure to other toxins, is rarely seen in the United States today (12). Walsh, et al. (23) have observed that when TA is found it is usually present in association with nutritional or idiopathic vitamin deficiencies. Victor (22) recently observed that the type of visual defect seen in tobacco amblyopia may be found in clinical circumstances in which tobacco Is clearly not a causative factor. He questions whether TA is distinguishable from other forms of amblyopia. The prevalence of this disorder has been variously estimated in the past at from 0.5 to 1.5 percent of all eye clinic patients (20, 23). However, currently in the United States, it appears to be a rare condition. Silvette, et al. (17) have observed that the incidence of tobacco amblyopia appears to have decreased substantially during the past decades. Other authors (3, 15) have also commented on this trend. Although reference has been made to the increased fre- quency of certain types of tobacco usage in patients with this dis- order, adequate population studies with proper controls have yet to be performed. The association of this disorder with the use of tobacco is strengthened by the frequent clinical observations of improvement following the cessation of smoking although improve- ment has been noted by some to occur without cessation. Research into the pathogenesis of tobacco amblyopia has cen- 531 tered upon the interrelationships of cyanide metabolism, vitamin B,2, and other vitamin deficiencies. Three reviews of this material have recently appeared (7, 12, 22). Numerous studies reviewed in these articles suggest that tobacco amblyopia may result from the incomplete detoxification of the cyanide present in tobacco smoke. This failure of detoxification may stem from or be intensified by inadequate dietary intake of necessary nutritional factors. This may be the reason for the association of this disorder with exces- sive alcohol intake and with its related nutritional deficits (2, 4, 6, 8,9, 10, 11, 13,14, 16, 18, 19, 21, 24, 26, 27,28). SUMMARY AND CONCLUSIONS Tobacco amblvopia is presently a rare disorder in the United States. The evidence suggests that this disorder is related to nutri- tional or idiopathic deficiencies in certain detoxification mechan- isms, particularly in handling the cyanide component of tobacco smoke. REFERENCES (1) CANADIAN MEDICAL ASSOCIATION JOURNAL. Tobacco amblyopia. (Edi- torial) Canadian Medical Association Journal 102(4): 420, February 28, 1970. (2) CursHoi, IL. A., BRONTE-StEwart, J., FOULDS, W.S. Hydroxocobalamin versus cyanocobalamin in the treatment of tobacco amblyopia. Lancet 2(7513): 450-451, August 26, 1967. (3) Daxrsy, P. W., Wicson, J. Cyanide, smoking, and tobacco amblyopia. Observations on the cyanide content of tobacco smoke. British Journal of Ophthalmology 51(5) : 336-338, May 1967. (4) Drexrus, P. M. Blood transketolase levels in tobacco-alcohol amblyopia Archives of Ophthalmology 74(5): 617-620, November 4965. (5) Duxpny, E. B. Alcohot and tobacco amblyopia: A historical survey. American Journal of Ophthalmology 68(4): 569-578, October 1969. (6) Fou.ps, W. S., BRonTe-STewaRT, J. M., CuisHo_M, I. A. Serum thio- cyanate concentrations in tobacco amblyopia. Nature 218(5141) : 586, May 11, 1968. Foutps, W. S., Cant, J. S., CH1sHoim, YT. A., BRONTE-STEWART, d., Witson, J. Hydroxocobalamin in the treatment of Leber’s hereditary optic atrophy. Lancet 1(7548) : 896-897, April 27, 1968. Fouups, W. S., CuisHoi, I. A., BRonTe-Stewakrr, J., Witson, T. M. Vitamin B,., absorption in tobacco amblyopia. British Journal of Ophthalmology 53(6) : 393-397, June 1969. Founps, W. S., CHISHOLM, I. A., BRONTE-STEWART, J., Wrison, T. M. The optic neuropathy of pernicious anemia. Archives of Ophthalmol- ogy &2(4) : 427-432, October 1969. FREEMAN, A. G., HEATON, J. M. The aetiology of retrobulbar neuritis in 908-911, April 29, (7) (8) (9) (10) Addisonian pernicious anaemia. Lancet 1(7183) : 1961. 532 (11) Heaton, J. M., McCormicn, A. J. A., FREEMAN, A. G. Tobacco amblyo- pia: A clinical manifestation of vitamin-B,, deficiency. Lancet 2(7041) : 286-290, August 9, 1958. (12) Knox, D. L. Neuro-ophthalmology. Archives of Ophthalmology 83(1): 103-127, January 1970. (13) LinpstRanp, K., WiLson, J., MattHews, D. M. Chromatography and microbiological assay of vitamin B,, in smokers. British Medical Journal 2 (5520) : 988-990, October 22, 1966. (14) Linnett, J. C., Smitu, A. D. M., Smitu, C. L., WILson, J., MATTHEWS, D. M. Effects of smoking on metabolism and excretion of vitamin B,,. British Medical Journal 2(5599) : 215-216, April 27, 1968. (15) Scuepens, C. L. Is tobacco amblyopia a deficiency disease— Transactions of the Ophthalmological Society of the United Kingdom 66: 309-331, 1946. (16) ScHieverseIn, H., WERLE, E., Scnurz, E. K., BAUMEISTER, R. The influ- ence of tobacco smoke and nicotine on thiocyanate metabolism. Naunyn-Schmiedebergs Archiv fiir Pharmakologie und Experimentelle Pathologie 262(3) : 358-365, February 5, 1969. (17) Siverre, H., Haac, H. B., Larson, P. S. Tobacco amblyopia. The evolu- tion and natural history of a “tobaccogenic” disease. American Journal of Ophthalmology 50(1): 71-100, January 1960. (18) Snuts, A. D. M. Retrobulbar neuritis in Addisonian pernicious anae- mia. (Letter) Lancet 1(7184): 1001-1002, May 6, 1961. (19) SMirH, A. D. M., Duckett, S. Cyanide, vitamine B,,, experimental demyelination and tobacco amblyopia. British Journal of Experimen- tal Pathology 46(6) : 615-622, December 1965. (20) Traquair, H. M. Toxic amblyopia, including retrobulbar neuritis. Trans- actions of the Ophthalmological Society of the United Kingdom 50: 351-385, 1930. (21) Victor, M. Tobacco-alcohol amblyopia. A critique of current concepts of this disorder, with special reference to the role of nutritional deficiency in its causation. Archives of Ophthalmology 70(3): 313-318, Septem- ber 1963. (22) Vicror, M. Tobacco amblyopia, cyanide poisoning and vitamin B,, de- ficiency. A critique of current concepts. Chapter 3. IN: Smith, J. L. (Editor) Neuro-Ophthlamology. Symposium of the University of Miami and the Bascom Palmer Eye Institute. Hallandale, Florida, Huffman Publishing Co., 1970. pp. 33-48. - (23) Watsu, F. B., Hoyt, W. F. (Editors) Neurotoxic substances affecting the visual and ocular motor systems. Chapter 15: IN: Clinical Neuro- Ophthalmology, Volume 3, 3rd Edition. Baltimore, The Williams & Wilkins Company, 1969. pp. 2613-2616. (24) WAaTSON-WILLIAMS, E. J., BoTtoMtey, A. C., AInLEY, R. G., PHILLIPS, C. I. Absorption of vitamin B,. in tobacco amblyopia. British Journal of Ophthalmology 53(8) : 549-552, August 1969. (25) Witson, J. Leber’s hereditary optic atrophy: A possible defect of cya- nide metabolism. Clinical Science 29(3): 505-515, December 1965. (26) Witson, J., MartrHews, D. M. Metabolic inter-relationships between cyanide, thiocyanate and vitamin B,, in smokers and nonsmokers. Clinical Science 31(1): 1-7, January 1966. 533 (27) Wokes, F., Picarp, C. W. The role of vitamin B,. in human nutrition. Clinical Nutrition 3(5) : 383-390, September-October 1955. (28) Wynoer, E. L., HOFFMANN, ID. Certain constituents of tobacco products. Chapter 8. K. Vapor phase af tobacco smoke. IN: Wrynder, E. L., Hoffmann, P. (Editors). Tobacco and Tobaceo Smoke. Studies in Ex- perimental Carcinogenesis, New York, Academic Press, 1967. pp. 451-453. 534 Chapter 10 Pipes and Cigars Source: 1973 Report, Chapter 6, pages 165 - 236. 535 Contents Introduction _.....222-2 2.22 The Prevalence of Pipe, Cigar, and Cigarette Usage._________ The Definition and Processing of Cigars, Cigarettes, and Pipe Tobaccos...-._-- 222-22 eee Mortality Overall Mortality........22..2222.- 2-2 Mortality and Dose-Response Relationships Amount Smoked___-_- 2 2-222 Inhalation.-.__-_ 2-222 List of Figures Figure 1.—Inhalation among pipe smokers by age... Figure 2.—Inhalation among cigar smokers by age—Ham- mond___ 2222 Page S41 543 545 547 549 550 553 559 559 560 561 563 567 373 5890 580 585 592 592 599 600 554 555 555 Figure 5.—Percent distribution of 130 brands of cigarettes and 25 brands of little cigars by nicotine content._...._.-____- List of Tables Table 1.—Percent distribution of U.S. males aged 21 and older by type of tobacco used for the years 1964, 1966, and 1970__ Table 2.—Percent distribution of U.S. males by type of tobacco used and age for 1970__.____.__.____-. 2222 ee. Table 3.—Percent distribution of British males aged 25 and older by type of tobacco used for the years 1965, 1968, and Table 4.—Amounts of several components of 1 gram of par- ticulate material from mainstream smoke of tobacco prod- Table 5.—A comparison of several chemical compounds found in the mainstream smoke of cigars, pipes, and cigarettes____ Table 6.—Mortality ratios for total deaths by type of smoking (males only). ....2222 22-2 ee Table 7.—Mortality ratios for total deaths of cigar and pipe smokers by amount smoked—Hammond and Horn_______- Table 8.—Mortality ratios for total deaths of cigar and pipe smokers. by amount smoked—Best_..._-.__.____-_.___.__. Table 9.—Mortality ratios for total deaths of cigar and pipe smokers by age and amount smoked—-Kahn_.____________ Table 10.—Mortality ratios for total deaths of cigar and pipe smokers by amount smoked—Hammond__._____________. Table 11.—The extent of inhaling pipes, cigars, and cigarettes by British males aged 16 and over in 1968 and 1971_______ Table 12.—Inhalation among cigar, pipe, and cigerette smokers by age—Doll and Hill__-..-- 28 Table 13.—Mortality ratios for total deaths of cigar and pipe smokers by age and inhalation—Hammond._____________. Table 14.—Percentage of British male cigar smokers who re- ported inhaling a lot or a fair amount by type of product smoked... Table 15.—Percentage of individuals reporting inhalation of “almost every puff” of tobacco smoke by current and pre- vious tobacco usage and type of tobacco used____.________ Table !6.—Percentage of British males who reported inhaling a lot or fair amount of cigar smoke by current and previous tobacco usage and type of tobacco previously smoked (1968) _- 22. 538 Page 596 543 544 544 547 548 550 551 551 552 552 556 556 557. 557 558 558 Table 17.—Extent of reported inhalation of cigar smoke by British male cigar smokers who were ex-cigarette smokers in 1968, analyzed by extent of reported inhalation of cigarette smoke when previously smoking cigarettes__~.------------- Table 18.—Mortality ratios for total cancer deaths in cigar and pipe smokers. A summary of prospective epidemiological studieS.._..._------------- eee ee eee Table 19.—Relative risk of Jip cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A summary of retrospective studies... -_-----------------------7-77-7577 Table 20.—Mortality ratios for oral cancer in cigar and pipe smokers. A summary of prospective epidemiological studies- - Table 21.—Relative risk of oral cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A sum- mary of retrospective studies- - ~~ ----------------r--7 777 Table 22.—-Mortality ratios for cancer of the larynx in cigar and pipe smokers. A summary of prospective epidemiological studieS._..___-----e ne eee ener Table 23.—Relative risk of cancer of the larynx for men, com- paring cigar, pipe, and cigarette smokers with nonsmokers. A summary of retrospective studies__.___---------------- Table 24.—Mortality ratios for cancer of the esophagus in cigar and pipe smokers. A summary of prospective epidemio- logical studies....------------------------070 rrr Table 25.—Relative risk of cancer of the esophagus for mep, comparing cigar, pipe, and cigarette smokers with non- smokers. A summary of retrospective studies_.._~---------- Table 26.—-Mortality ratios for lung cancer deaths in male cigar and pipe smokers. A summary of prospective studies. .-- Table 27.—Lung cancer death rates for cigar and pipe smokers by amount smoked—Doll and Hill_._-__.--------------- Table 28.—Lung cancer mortality ratios for cigar and pipe smokers by amount smoked—Kahn-_-_-.--------------7-- Table 29.—Relative risk of lung cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A summary of retrospective studies._------------------7777 Table 30.—Changes in bronchial epithelium of male cigar, pipe, and cigarette smokers as compared to nonsmokers- - - - Table 31.—Tumorigenic activity of cigar, pipe, and cigarette smoke condensates in skin painting experiments on animals _- Table 32.—Mortality ratios for cardiovascular deaths in male cigar and pipe smokers. A summary of prospective epi- demiological studies_.--.-----------------77 77007077707 Page 559 559 562 563 564 566 568 570 571 574 574 575 576 579 583 586 539 Page Table 33.— Mortality ratios for chronic obstructive pulmonary deaths in male cigar and pipe smokers. A summary of pros- pective epidemiological studies..-...-.----. 589 Table 34.—Prevalence of respiratory symptoms and illness by type of smoking.____. 222 ee 590 Table 35.—Pulmonary function values for cigar and pipe smokers as compared to nonsmokers.....-.-...-.. 591 Table 36.—Mortality ratios for peptic ulcer disease in male cigar and pipe smokers. Summary of prospective studies. __ 592 Table 37.—Shipment of small and large cigars destined for domestic consumption (1970, 1971, 1972)_...- 597 Table 38.-—Selected compounds in mainstream smoke... _. 598 Table 39.—The pH of the mainstream smoke of selected tobacco products. _-___.___..- ee 538 540 Introduction This chapter is a review of the epidemiological, pathological, and experimental data on the health consequences of smoking cigars and pipes, alone, together, and in varicus combinations with cigarettes. Previous reviews on the health consequences of smoking have dealt primarily with cigarette smoking. Although some of the material on pipes and cigars presented in this chapter has been presented in previ- ous reports of the Surgeon General, this is the first attempt to summa- rize what is known about the health effects of pipe and cigar smoking. Since the use of pipes and cigars is limited almost exclusively to men in the United States, only data on men are included in this review. The influence of pipe and cigar smoking on health is determined by examining the overall and specific mortality and morbidity ex- perienced by users of these forms of tobacco compared to nonsmokers. Epidemilogical evidence suggests that individuals who limit their smoking to only pipes or cigars have overall mortality rates that are slightly higher than nonsmokers. For certain specific causes of death, however, pipe and cigar smokers experience mortality rates that are as great as or exceed those experienced by cigarette smokers. This analysis becomes more complex when combinations of smoking forms are examined. The overall mortality rates of those who smoke pipes, cigars, or both in combination with cigarettes appear to be inter- mediate between the high mortality rates of cigarette smokers and the lower rates of those who smoke only pipes or cigars. This might seem to suggest that smoking pipes or cigars in combination with ciga- rettes diminishes the harmful effects of cigarette smoking. However, an analysis of mortality associated with smoking combinations of ciga- rettes, pipes, and cigars should be standardized for the level of con- sumption of each of the products smoked in terms of the amount smoked, duration of smoking, and the depth and degree of inhalation. For example, cigar smokers who also smoke a pack of cigarettes a day might be expected to have mortality rates somewhat higher than those who smoke only cigarettes at the level of a pack a day, assuming that both groups smoke their cigarettes in the same way. Mixed smokers who inhale pipe or cigar smoke in a manner similar to the way they smoke cigarettes might be expected to have higher mortality rates than mixed smokers who do not inhale their cigars and pipes and also 541 resist inhaling their cigarettes. Unfortunately, little of the published material on mixed cigarette, pipe, and cigar smoking contains these types of analvses or controls. -\ paradox seems to exist. bet ween the mortality rates of ex-smokers of pipes and cigars and ex-smokers of cigarettes. Ex-cigarette smokers experience a relative decline in overall and certain specific causes of mortality following cessation. This decline is important but indirect evidence that cigarette smoking is a major cause of the elevated mor- tality rates experienced by current cigarette smokers. In contrast to this finding, several prospective epidemiological investigations, Hammond and Horn (40), Best (9), Kahn (50), and Hammond (38), have reported higher death rates for ex-pipe and ex-cigar smokers than for current pipe and cigar smokers. This phenomenon was ana- lyzed by Hammond and Garfinkel (39). The development of il health often results in a cigarette smoker giving up the habit, reducing his daily tobacco consumption, switching to pipes or cigars, or choosing a cigarette low in tar and nicotine. In many instances, a smoking- related disease is the cause of ill health. Thus, the group of ex-smokers includes some people who.are ill from smoking-related diseases, and death rates are high among persons in ill health. As a result, ex-cigarette smokers initially have higher overall and specific mortality rates than continuing cigarette smokers, but be- cause of the relative decrease in mortality that occurs in those who quit smoking for reasons other than ill health, and because of the dwindling number of ill ex-smokers, a relative decrease in mortality is observed (within a few years) following cessation of cigarette smoking. The beneficial effects of cessation would be obvious sooner were it not for the high mortality rates of those who quit smoking for reasons of illness. A similar principle operates for ex-pipe and ex- cigar smokers, but because of the lower initial risk of smoking these forms and therefore the smaller margin of benefit following cessation, the effect produced by the ill ex-smokers creates a larger and more Persistent impact on the mortality rates than is seen in cigarette smoking. _ For the above reasons a bias is introduced into the mortality rates of current smokers and ex-smokers of pipes and cigars, so that a more accurate picture of mortality might be obtained by combining the ex-smokers with the current smokers and looking at the resultant mortality experience, Because of a lack of data that would allow a precise analysis of mortality among ex-pipe and ex-cigar smokers, a detailed analysis of these groups could not be undertaken in this review. . For each specific cause of death, tables have been prepared which summarize the mortality and relative risk ratios reported in the major 542 prospective and retrospective studies which contained information about pipe and cigar smokers. The smoking categories used include: cigar only, pipe only, total pipe and cigar, cigarette only, and mixed. The total pipe and cigar category includes: those who smoke pipes only, cigars only, and pipes and cigars. The mixed category includes: those who smoke cigarettes and cigars; cigarettes and pipes; and cigarettes, pipes, and cigars. Mortality and relative risk ratios were _ calculated relative to nonsmokers. The Prevalence of Pipe, Cigar, and Cigarette Usage The prevalence of pipe, cigar, and cigarette smoking in the United States was estimated by the National Clearinghouse for Smoking and Health from population surveys conducted in 1964, 1966, and 1970 (98, 99, 100). In each survey, about 2,500 interviews were conducted on a national probability sample stratified by type of population and geographic area. The use of these products among adults aged 21 and older is summarized in tables 1 and 2. The prevalence of pipe, cigar, and cigarette smoking in Great Britain for the years 1965, 1968, and 1971 is presented in tables. Tape 1.—Percent distribution of U.S. male smokers aged 21 and older by type of tobacco used for the years 1964, 1966, and 1970 Forms used 1064 1964 1970 (percent) (percent) (percent) 1. Cigar only. __--------------------00 0077 6.38 5.5 5.6 2. Pipe only____--------------+-----777777 1.7 3.0 3.6 3. Pipe and cigar--.-.---------------77-777 3.9 49 44 4. Cigarette only_.-------------------7777> 28. 6 31.2 25.9 5. Cigarette and cigar._------------------7- 11.3 9.9 6.6 6. Cigarette and pipe. --------------------- 5.3 4.9 5.3 7. Cigarette, pipe, and cigar. -.------------- 7.7 6.3 46 8. Nonsmoker_...----------------7-7 777777 34.7 34.3 44.0 oo Total. ._---------------- 7-7-0007 100. 0 100. 0 100. 0 a Number of persons in sample-~------------- 2, 389 2, 679 2, 861 Total pipe users (2+3+ 647)_-------------- 18. 7 9. 2 17.9 Total cigar users (1+34+547)-------------- 29.9 26.7 21.2 Total cigarette users (4454+647)_---------- 529 52. 4 42.3 Source. U8. Department of Health, Education, and Welfare (98, 09, 100). 543 TABLE 2.—Percent distribution of U.S. male smokers by type of tobac- co used and age for 1970 Age groups Forms used 21 to 34 Btow 4to5t SStoGd 65to7S + 1. Cigar only_..-------------- 3.7 6.5 4.7 6.7 9.3 2. Pipe only_.---------------- 4.3 3.5 3.0 3.2 3.6 3. Pipe and cigar__.-.--------- 3.8 3.3 5. 2 4.4 6.9 4. Cigarette only._.._--------- 28. 8 29. 0 27.1 24.3 13. 6 5. Cigarette and cigar__..------ 6.8 10. 4 5.5 5. 2 4.2 6. Cigarette and pipe_--------- 6.6 4.4 5. 6 4.0 3.8 7. Cigarette, pipe, and cigar---- 5.8 48 5.0 4.0 14 §. Nonsmoker._-.------------- 40. 2 38. 1 43.9 48. 2 57. 2 Total___..------------- 100.0 100.0 100.0 100.0 100. 0 Number of persons in sample--- 1, 009 528 523 405 388 Total pipe users_.------------- 20. 5 16.0 18. 8 15. 6 15. 7 Total cigar users_.------------ 20. 1 25. 0 20. 4 20. 3 21.8 Total cigarette users_--------- 48.1 48. 6 43.3 37.5 23. 0 Bource: U.S. Department of Health, Education, and Welfare (/00). TABLE 3.—Percent distribution of British male smokers aged 25 and older by type of tobacco used for the years 1965, 1968, and 1971 Forms used 1963 1968 1971 1. Cigars only_..-.---------------------+-- 1.9 2.8 3.3 2. Pipe only----------------------------7- 3.1 5.6 5.9 3. Cigarettes only. __.__------------------- 46. 8 A5. 7 40.8 4, Cigarettes and pipe. -------------------- 8.0 7.0 6.1 5. Mixed smokers. __._-------------------- 7.5 9.1 8.4 6. Nonsmokers_..._----------------------- 30. 7 29. 9 35. 4 Total.__._.---------------------- 77> 100. 0 100. 0 106. 0 ee Number of persons in sample-- - ------------ 3, 576 3, 566 3, 594 i Total pipe users-_.------------------------- 13.9 14.3 13. 3 Total cigar. __---------------------------- 9.0 11.7 11.3 67.6 67. 6 61.6 Total cigarette Source: Todd 544 .G. F. (95). The Definition and Processing of Cigars, Cigarettes, and Pipe Tobaccos Cigarettes The U.S. Government has defined tobacco products for tax pur- poses. Cigarettes are defined as “(1) Any roll of tobacco wrapped in paper or in any substance not containing tobacco, and (2) any roll of tobacco wrapped in any substance containing tobacco which, because of its appearance, the type of tobacco used in the filler, or its packaging and labeling, is likely to be offered to, or purchased by, consumers 88 a cigarette described in subparagraph (1).” Cigarettes are further classified by size, but virtually all cigarettes sold in the United States are “small cigarettes” which by definition weigh “not more than 3 pounds per thousand” which is not more than 1.361 grams per cigarette (96). ‘American brands of cigarettes contain blends of different grades of Virginia, Burley, Maryland, and oriental tobaccos. Several varieties of cigarette tobaccos are flue-cured. In this process, tobacco leaves are cured in closed barns where the temperature is progressively raised over a period of several days. This results in “color setting,” fixing, and drying of the leaf. The most conspicuous change is the conversion of starch into simpler sugars and suppression of oxidative reactions. Flue-cured tobaccos produce an acidic smoke of light aroma (35, 112). Cigars Cigars have been defined for tax purposes as: “Any roll of tobacco wrapped in leaf tobacco or in any substance containing tobacco (other than any roll of tobacco which is a cigarette within the meaning of subparagraph (2) of the definition for cigarette)” (172). In order to clarify the meaning of “substance containing tobacco” the Treasury department has stated that, “The wrapper must (1) contain a signifi- cant proportion of natural tobacco; (2) be within the range of colors normally found in natural leaf tobacco; (3) have some of the other characteristics of the tobaccos from which produced; e.g., nicotine content, pH, taste, and aroma; and (4) not be so changed in the reconstitution process that it loses all the tobacco characteristics” (102). Further, “To be a cigar, the filler must be substantially of tobaccos unlike those in ordinary cigarettes and must not have any added flavoring which would cause the product to have the taste or aroma generally attributed to cigarettes. The fact that a product does 545 not resemble a cigarette (such as manv large cigars do not) and has a distinctive cigar taste and aroma is of considerable significance in making this determination” (762). Cigars are also classified by size. “Small cigars” weigh not more than 3 pounds per thousand and “large cigars” weigh more than 3 pounds per thousand. “Large cigars” are further divided into seven classes for tax purposes based on the retail price intended by the manufacturer for such cigars (96). Cigars are made of filler, binder, and wrapper tobaccos. Most cigar tobaccos are air-cured and then fermented. More recently, reconsti- tuted cigar tobaccos have been used as wrapper, binder, or both. Cigars are either hand-rolled or machine made. Some brands of small cigars are manufactured on regular cigarette making machines. The aging and fermentation processes used in cigar tobacco production produce chemical catalytic, enzymatic. or bacterial transformations as evi- denced by increased temperature, oxygen utilization, and carbon dioxide generation within fermenting cigar tobaccos. In this complex process, up to 20 percent of the dry weight of the leaf is lost through decreases in the concentration of the most readily fermentable ma- terials such as carbohydrates, proteins. and alkaloids. The flavor and aroma of cigar tobaccos are in large measure the results of precisely controlled treatment during the fermentation process (35, 96, 112). Pipe Tobaccos The definition of pipe tobacco used by the U.S. Government was repealed in 1966 and there is no Federal tax on pipe tobaccos. The most popular pipe tobaccos are made of Burley; however, many pipe tobaccos are blends of different types of tobacco. A few contain a significant proportion of midrib parts that are crushed between rollers. “Saucing” material, or casings containing licorice, sweetening agents, sugars, and other flavoring materials are added to improve the flavor, . aroma, and smoke taste. These additives modify the characteristics — of smoke components (112). Conclusion Because of the unique curing and processing methods used in the production of cigar and pipe tobaccos. significant physical and chemi- cal differences exist between pipe and cigar tobaccos and those used in 546 cigarettes. The extent to which these changes may alter the health consequences of smoking pipes and cigars can best be estimated by an analysis of the potentially harmful chemical constitutents found in the smoke of these tobaccos. the tumorigenic activity of smoke conden- sates in experimental animals, and a review of the epidemiological data which has accumulated on the health etfects of pipe and agar smoking. Chemical Analysis of Cigar Smoke Only a few studies have been conducted that compare the chemical constituents of cigar smoke with those found in cigarette smoke. Hoffmann, et al. (43) compared the yields of several chemical com- ponents in the smoke from a plain 85 mm. cigarette, two types of cigars, and a pipe. The particulate matter, nicotine, benzo(a) pyrene, and phenols were determined quantitatively in the smoke of these tobacco products. One cigar tested was a 135-mm.-long, 7.8-g., U.S.- made cigar. The other was a handmade Havana cigar 147 mm. long weighing 8.6 g. The relative content of nicotine in the particulate matter produced by the cigars was similar to that of the cigarette tars. The benzo(a)pyrene and phenol concentrations in the cigar condensate was two to three times greater than in cigarette “tar” (table 4). Kuhn (58) compared the alkaloid and phenol content in conden- sates from an 80-mm. Bright-blend cigarette sold commercially in Austria with that obtained from 103-mm. cigars. These were tested Amounts of several components of 1 g. of perticulate material TABLE 4. from mainstream smoke of tobacco products Tobacco product ! - Standard 85 mm. 83mm. Compound U.S. Havana pipe Cigarette plain U.S. plain U.S. cigar A cigar B tobacco tabscco cigarette cigarette (b} (b) in pipe in pipe (a) (b) (bd) Nicotine (mg.)---------- 46.2 63. 6 56. 1 61.0 65. 9 774 Benzo(a)pyrene (yg.)- --- 3.9 3.6 6.0 3.6 1.2 1.3 Phenol (mg.)_----------- 8.2 67 15.0 7.3 2.9 4.1 »+Cresol (mg.)_-~------- 1.6 1.7 1.9 La .6 8 n+ p-Cresol (mg.)-_----- 4.8 3.8 5.6 34 L4 1.9 n+p-Ethylphenol (mg.)-- 1. i 1.5 i 1.3 .7 7 4 Smoking conditions: (a) 1 pul per minute, duration 2 sec., puff volume 35 ml. (b) 2 putts per minute, duration 2sec., put volume 335 ml. Source: Hoffmann, et al. (43). 547 with and without the use of a cellulose acetate filter. The concentra- tions of total alkaloids and phenol in the cigar smoke condensate were essentially the same as in the cigarette condensate, but pyridine values were about 214 times higher in the cigar condensate. Campbell and Lindsey (/7) measured the polycyclic hydrocarbon levels in the smoke of a small popular-type cigar 8.8 cm. long, weighing 1.9 g. Significant quantities of anthracene, pyrene, fluoranthene, and benzo(a)pyrene were detected in the unsmoked cigar tobacco, in con- centrations much greater than those found in Virginia cigarettes but of the same order as those found in some pipe tobaccos. The smoking process contributed considerably to the hydrocarbon content of the smoke. Table 5 compares the concentrations in the mainstream smoke of cigarettes, cigars, and pipes of four hydrocarbons frequently found in condensates. The authors reported that the mainstream smoke from a popular brand of small cigar contained the polycyclic aromatic hydrocarbons; acenaphthylene, phenanthrene, anthracene, pyrene, fluoranthene, and benzo(a) pyrene. The concentrations of these hydro- carbons in the mainstream smoke were greater than those found in Virginia cigarette smoke. Osman, et al. (69) analyzed the volatile phenol content of cigar smoke collected from a 7-g. American-made cigar with domestic filler. After quantitative analysis of phenol, cresols, xylenols, and meta and para ethyl phenol, the authors concluded that the levels-of these com- pounds were generally similar to those reported for cigarette smoke. Osman and Barson (68) also analyzed cigar smoke for benzene, toluene. ethyl benzene, m-, p-, and o-xylene, m- and p-ethyltoluene, 1.2,4-trimethylbenzene, and dipentene, and generally found levels within the range of those previously reported for cigarette condensates. In summary. available evidence suggests that cigar smoke contains many of the same chemical constituents, including nicotine and other alkaloids, phenols, and polycyclic aromatic hydrocarbons as are found TasLe 5.—A comparison of several chemical compounds found in the mainstream smoke of cigars, pipes, and cigarettes Micrograms per 100 g. of tobacco consumed Compound Cigars Pipes ! Cigarettes Acenaphthylene___------------------------ 1.6 29. 1 5.0 Anthracene____--_--------------------- 7" 11.9 110. 0 10.9 Pyrene_____-------------------- 7-00-00 17.6 75. 5 12.5 3.4 8. 5: .9 ‘This Is alight pipe tobacco. Bource: Campbell, J. M., Lindsey, A. J.a7). 548 in cigarette smoke. Most of these compounds are found in concentra- tions which equal or exceed levels found in cigarette “tar.” A more complete picture of the carcinogenic potential of cigar “tars” is ob- tained from experimental data in animals. Mortality Overall Mortality Several large prospective studies have examined the health conse- quences of various forms of smoking. The results of these investiga- tions have been reviewed in previous reports of the Surgeon General in which the major emphasis has been on cigarette smoking and its effect on overall and specific mortality and morbidity. The following pages present a current review of the health consequences of smoking pipes and cigars. Data from the prospective investigations of Dunn, et al. (3/), Buell, et al. (26), Hirayama (42), and Weir and Dunn (705) are not cited, because in these studies a separate category for pipe and cigar smokers was not established. The smoking habits and mortality experience of 187,783 white men between the ages of 50 and 69 who were followed for 44 months were reported by Hammond and Horn (41). The overall mortality rates of men who smoked pipes or cigars were slightly higher than the rates of men who never smoked. The overall mortality rate of cigar smokers was shghtly higher than that of pipe smokers. In a study of 41,000 British physicians, Doll and Hill (26, 27) re- ported the overall mortality of pipe and cigar smokers as being only 1 percent greater than that among nonsmokers. Best: (9), in a study of 78,000 Canadian veterans, reported overall mortality rates of pipe and cigar smokers slightly above those of nonsmokers. Kahn (50) exam- ined the death rates and smoking habits of more than 293,000 U.S. veterans and Hammond (38) examined the smoking habits of and mortality rates experienced by 440,559 men. In these studies, pipe _ smokers experienced mortality rates similar to those of men who never smoked regularly, whereas cigar smokers had death rates somewhat higher than men who never smoked regularly. Table 6 summarizes the results of these five studies. Thus, data from the major prospective epidemiological studies demonstrate that the use of pipes and cigars results in a small but defi- nite increase in overall mortality. Cigar smokers have somewhat higher death rates than pipe smokers, and mixed smokers who use cigarettes in addition to pipes and cigars appear to experience an inter- mediate level of mortality that approaches the mortality experience of cigarette smokers. 495-023 O—73-——_13 549 TasLe 6.—Mortality ratios for total deaths by type of smoking (nales only) Smoking type Author, reference Non- Cigar Pipe Cigsr Cigarette Cizarette Mixed Cigarette smoker only only and and cigar and pipe {cizsrette only pipe and other) Hammond and Horn ! (40)_-- 1.00 1.22 1.12 14.10 1. 36 1. 50 1. 43 1. 68 Doli and Hill (26)_..------ 1.00 .-.. ---. LOL --.---) ------- Lit 1. 238 Best (9)__-.---- 1.00 1.06 21.05 .98 1. 22 1. 26 1.13 1.54 Kahn (60)------ 1.00 1.10 1.07 1.08 -_-.-. ------- 1.51 1. 84 Hammond? (38) __.------ 1.00 21.25 1.19 LOL --_--- ------- 1. 57 1. 86 5 Only mortality ratios for ages 50 to 69 are presented. 1 Only mortality ratios for ages 55 to 64 are presented. ’ Mortality and Dose-Response Relationships A consistent association exists between overall mortality and the total dose of smoke a cigarette smoker receives. The methods most frequently used to measure dosage of tobacco products are: Amount smoked, degree of inhalation, duration of smoking experience, age at initiation, and the amount of tar in a given tobacco product. For cigarette smokers, the higher the dose as measured by any of these parameters, the greater the mortality. The significance of the small increase in overall mortality that occurs for the entire group of pipe and cigar smokers can be analyzed by examining the mortality of subgroups defined by similar measures of dosage as used in the study of cigarette smokers. AMOUNT SMOKED Hammond and Horn (40) reported an increase in the overall mor- tality of pipe and cigar smokers with an increase in the amount smoked. Individuals who smoked more than four cigars a day or more than 10 pipefuls a day had death rates significantly higher than men who never smoked (P<0.05 for cigar smokers and P<0.05 for pipe smokers) (table 7), Cigar and pipe users who smoked less than this amount experienced an overall mortality similar to men who never 550