TABLE L?Z).-Relative risk of lung cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A am- manj of relrospective stwlies Number --- Levin, et al. (60): Caqca- -_______--_-___-_-____ 236 Control8 ______ ___ _______ -___ _ 481 Schrck, et al. (81): CRsCS_-..--._...-._------.-- 82 Controls- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 522 Wynder and Graham (111): CaScS--..--.-__...------__-- 605 Controls- - - _ - _ _. _ _ _ _ + _ _ _ _ _ _ _ 780 Doll and Hill (%6): Csses_.-_._.___-..---~~~---- 1,357 Controls _.___________________ I, 357 Koulumies (66) : Cases----.------------------ 812 Controls--- _ - _ - - - - - - - - - - - _ - _ 300 Sadowsky, et al. (77): Cases- --__-_.__-____________ 477 Controls _____________ jr ______ 615 Relative risk ____________ Pcrccnt cfi.qes..- _________ Percent controlv _________ Relative risk ____________ Percent cfws ___________ Percent controls _________ Relative risk ____________ Percent cases- _ _________ Percent controls _________ Relative risk ____________ Percent cases ___________ Percent controls _________ Relative risk _____.______ Percent cases ___________ Percent controls-.. _ _ _ _ _ _ _ Relative risk _______.____ Percent casc3 ___________ Percent controls _________ 1. 0 0. 7 15 11 22 23 1.0 .6 15 4 22 23 1. 0 5. 1 1 4 15 8 1.0 --- .._-__ 5 --m-w_-__ 5' .- -.---__ 1.0 -- -______ .G ---_-_-__ 18 e--v be__ _ 1. 0 2. 4 4 2 13 3 0. 8 - _ - _ - - -. . 14 -_--_-___ 25 _ _ _ _ _ _ _ _ _ 5' 7 --.-____. - _ - - _ -. _ _ 11 -_.._____ 3.6 ____.____ 4 --a----_- 12 --- --.__- 2. 1 _ I - _ - _ _ _ _ GG - - - - - _ - _ _ 44 _ - _ _ _ _ _ _ _ 1. 7 - - _ _ - -, -. - 61 _ _- --- __- 50 - _ - _. _ _ _. 15.7 --.---__- 91 ________. 65 --- -*-__- 9. 6 _. _ - _ _ - _ _ 74 - - - - _ - _. - 69 . _ _ _ _ _ _ _ _ 3. 7 5. 6 57 31 53 13 Wyndcr and Cornfield (I IO) : CIL~CS. -_ - - -- - -_ --- __________ 63 CAmtrolu ____. . ____ _ ________ _ _ 133 Rnndig (74) : CLWS _ _ - - _ - - - - - - - - - _. _ - _ _ _ - _ 415 Controls _____________________ 381 hlills and Porter (66): CNCS_.---.._--..----------- 444 Controls ___-_-------- _----___ 430 hlills and Porter (66) : Crises--.---..--..----.._-..-_ 484 Controls _____________________ 1, 588 Schwartz and Dcnoix (8%) : Cnses.-...-.----...-~------- 430 Controls... _ _ _ - - _ _ __-_ __ _ ____ 430 Stocks (89) : CNes~_~_-_.---.-.-~-------~ 2,101 Cuntrols ______________-______ 5, QGO Lombard and Sncgircff (61) : CuJCS------.-----..------.-- 500 Contruls.... ---_____-_.___.__ 1, 839 I'ern11 (73) : cn GLW. - __-- __________.______ 1,477 : Guilrols... _ _ __ __ __ _ __ i ______ 713 Relative risk ____________ Pcrccnt CNCY-- _________ Pcrccnt controls ______-__ Relative risk ______ ______ Percent cases- _ _________ Percent controls _________ Relative risk ___________. Percent cases ___________ Percent controls _________ Relative risk ____________ Percent cases ___________ Percent controls _________ Relative risk __._________ Percent case3 ___________ Percent controls _______-_ Relative risk ____________ Percent cfws ___________ Percent controls _________ Relative rivk ____________ Percent cfuea-. _________ Percent controls .________ Rclntivc risk.--* _________ Percent craw --_________ Pcrccnt control8 -_-______ 1. 0 2. 5 4 0 - - - - - - _ _ - 4 13 6 _-__-_-__ 21 27 8 - - - - - _ - - - 1. 0 5. 3 5. 0 - - - - - - - - - 1 21 11 -------_- 6 19 11 -----_.__ 1.0 _---__--_ ---___-_ 0.0 7 ------_-_ ----_-__ 37 3i _________ ________ 26 1.0 __--___-- _---I--_ 2. 8 8 ----e-e-- ------__ 13 28 _________ ________ 1G 1. 0 - - -. _ _ - _ _ 4. 7 - - - - _ _. _ _ 1 ---- --__- 6 .__-._-__ 11 --_---_-_ 14 -________ 1. 0 _ - - - - - _ - - 3. 1 - - _ _ _ _ _ _ - 2 --e.m-_-- 9 _- ____._ _ 9 -*m-----_ 13 _ _ _ - _. - _ - 1.0 --_-___-- _---_--. 1. 7 2 o-_-mm-__ _-_-__-- 4 10 _--.--__- ----_-_. 15 1.0 -_----_ *_ 4.2 _-__.____ 7 -----em_- 4 --___-_-_ 39 - - _ - - _ _ _ - 5 ----____- 8.5 _________ 77 _ _ -_ _ _ _ _ _ 4s -_--- _-__ 5. 0 - _ _ _ _ - _ _ _ 67 - - - - - _ _ _ _ 64 - _ _ _ _ - _ _ _ 5.4 _________ 5s - - - - - - _ _ _ 43 _- --_ _ - - _ 4. 5 _ - -. _ _ -. _ 78 - _ _ - - _ _ _ - 57 _ _ - -. _ _ _ _ 13. 5 _----_.__ 90 _ _ _ - - _ _ _ _ 78 _ _ - - - - - _ - 5. 0 - - - - - - - _ _ 80 _ _ _ _ _ _ _ _ _ 76 _ __ __ _ -__ 8. 1 ---___- __ Qj ______ ___ 75 -- _ __ --_. 9. 2 Il. 1 77 13 SO 7 TABLE 29 .-Relutive risk oj lung cancer for men, conparing cigar, pipe, and cigarette smoker8 with nomokcrs. A e-urn- maq of relrospective hulks--Continued Wickcn (f&j): .Relntive risk ____ __ _ _ ____ Cases---.-..-.--_-.~.-....---. 1.0 --------- -_------ 2. 2 4. 3 4. 2 803 Percent cB9ea Controls ___________ 4 _________ ________ 10 78 7 __-__-_________________ 803 Percent controls _________ 14 _________ ________ 16 G4 G Abelin and Cscll (I): Relative risk ____________ Cascs--.--..---.~---~.......-. 1. 0 30. 7 21. 8 39. 9 31. 0 24. 7 118 Percent ca3e9. Controls ____-_____ 2 28 7 68 25 24 __-_---________________ 524 Percent control8 -________ 35 19 G 31 17 10 Wynder, et al. (116) : cases---..----__.........-.... Relative risk -___________ 1.0 ___---__- ---_-.-- 2.0 12. 4 _ --.--___ 210 Percent cases. Controls _-__._____ 3 ___._____ __._____ 5 92 _. - - - - _ - _ __._____._ ______FC_____ 420 Percent controls.Sm, __.__ 21 ___..____ ________ 15 47 - -. . . - - - _ TABLE 30.- Changes in bronchial epithelium of male cigar, pipe, and cigarette smokers as compared to nonsmokers 1st set (none vs. pipe vs. cigarette-matched on 1 :I basis) : Nonsmoker- _ _ _ _ _ ___. _ __ _ ____ __ _ ___ ____ Pipe only___--.--_......--------------- Cigarette only _________________________ 2d set (none vs. pipe VB. cigarette-matched on frequency basis) : Nonsmoker.-- _______ _____ __ _ ___ __ _ __ _. Pipe only ______________________________ Cignrcttc only-. _ ______________________ 3d set (none vs. cigar va. cigarette) : Nonsmoker-- _ _ __ __ ___ _ __ _ _ _______ ___ _ _ Cigar only _____________________________ Cignrcttc only __.______________________ 20 20 20 25 25 25 35 35 35 985 924 914 1, 24G l,lG4 1, 12G 22. 9 13. 4 .7 1, 277 G8. 7 38. 7 38. 2 1, 247 96. 3 88. 7 89. 5 1, 237 1,70G 27. 4 1,733 90. 8 1,520 91. 0 21. 7 G5. 5 96. 8 11. 2 2. G 1,031 10. 3 38. 1 37. 0 079 35. 0 88. 6 95. 2 082 72. 1 12. 7 .8 1, 748 40. 0 73. G 1, 8'28 92. 7 97. 8 1, G33 11. 5 37. 9 75. 5 15. 3 52. 5 80. 2 8ourm: Auerbach et al. (8). Tumorigcnic Activity The tumorigenic activity of tobncco smoke can be modified in both a quantitative and qualitative sense. Physical or chemical changes in tobacco that. result in n reduction of total particulate matter upon combusion of a given quantity of tobacco may result in a reduction of carcinogenic potcntinl. Such factors as tobacco selection, treatment, blending, cut, and additives may quantitatively alter tar production. Wrapper porosity and filtration may also affect tar production. Quantitative changes in the tumorigenic-activity of tobacco tar on a gram-for-gram basis can be produced by the selection and treatment of tobacco, the use of additives or tobacco sheets, or adjustments in the cut and packing density. Combustion temperature can also produce quantitative changes in the particulate matter of tobacco smoke. Although high-temperature burning produces less particulate matter in the smoke, it appears that tumorigenic components occur in higher concentration xhen tobacco is pyrolized at temperatures higher than 700" centigrade (34). Cigars, pipes, and cigarettes 5re similar in that they are smoked orally and have a common site of introduction to the body. The tissues of the mouth, larynx, pharynx, nnd esophagus appear to receive np- proximately equal exposure to the smoke of these products. Inhalation causes smoke to be drawn deeply into the lungs and also allows for systemic absorption of certain constituents of tobacco smoke which then can be carried further to other organs. Pipe tobacco and cigars vary from cigarettes in a number of charac- teristics that can produce both quantitative and qualitative changes in the total particulate matter produced by their combustion. Experi- mental evidence suggests that although there is some difference in the amount and quality of tar produced by cigars, this cannot account for the reduced mortality observed in cigar smokers compared to cigarette smokers. Experimental Studies Several experimental investigations have been conducted to examine the relative tumorigenic activity of tobacco smoks condenslttes obtained from cigarettes, cigars, and pipes. Most of these studies mere standard- ized in an attempt to make the results of the cigar and pipe experiments more directly comparable with the cigarette dat.a and most used the sl~aved skin of mice for the application of tar. Tars from cigars, pipes, and cigarettes were usually applied OJI an equal n-eight. basis SO that qunlitntire differences in the tars could be determined. In several ex- periments. the nicotine was extracted from the pipe and cigar conden- sates in an attempt to reduce the acute toxic effects that resulted in nnimals from the high concentrations of nicotine frequently found in these products. 580 JT'ynder snd ITtight (117) examined the diflerences in tumorigenic acti\-ity of pipe and cigarette condensates. Tars mere obtained by the SmokiIjg of 3 pop~ll3r br:~rd of king-size cignrettcs and the same +a- rette tc)bncco snloked in 12 standard-grade briar bon-1 pipes. not11 the cigarettes :trld pips were putfed three times a minute Ath a Q-second putf and a 35-m]. I-oltrme. Both the cigarcttcs and pipes attnincd similar masimum combustion zone temperzturcs, . hone\-er, the use of cigarette tobacco in the pipe resrtlted in a combustion chamber temperature that averaged about 150" centigrade higher thnn temperatures achieved when pipe tobacco was used. Chemical fractionation wss accomplished and equal concentrations of the neutral fraction were applied in t.hreo weekly applications to the shaved skin of C-IF', and Swiss mice. The results indicatet,hat. neutral tar obtained from cigarette tobacco smoked in pipes is more active than that obtained in the usual manner from cigarettes. About twice as many cancers acre obtained in both the CXF, and the Swiss mice, and the latent period x-as about 2 months shorter. Extending these data, Croninger, et al. (20) csamined the biologic activity of tars obtained from cigars. pipes, and cigarettes. Each form of tohacco was smoked as it was manufactured in a manner to simulate human smoking or to maintain tobacco combustion. Tlw ~rlrole tar was . nppired m drlutlons of one-to-one and one-to-two mith acetone to the shaved backs of female CAF, and female Swiss mice using three . npplwattonseach creek for the life-span of the animal. The nicotine was estracted from the pipe and cigar condensates to reduce Lhe acute toxicity of the solutions. The Swiss mice. pipe, cigar, and cigwette tars produced both benign and malignant tumors. The incidence rates of malignant tumors given as percents were: 44,41, and 37, respectively. These results suggested a somewhat higher degree of carcinogenic activity for cigar and pipe tars than for cigarette tar. Similar results n-we reported by Kensler (53) who applied conden- sates obtained from cigars and cigarettes to the shaved skin of mice. The incidence of papillomas produced bv cigar smoke concentrate was no diff'emnt from that of the cigarette"smoke condensate. Similarly, there xas no diBerence between cigar and cigarette smoke condensates when carcinoma incidences xrere compared. fJombur,oer, et al. (45) prepared tars from cigar, pipe, and cigarette tobaccos that were smoked in the form of cifarettes. In t.his way, all tobaccos were smoked in an ident.ical manner and uniform combustion temperatures xere achieved. Because of this standardization, differ- ences in tumor yield could be attributed to tobacco blend and not the manner in which the tax-s were prepared. The whole tar-s mere diluted one-to-one with acetone and applied to the shaved skin of C.iF, mice three times a ireek for the lifespan of the test animal. Skin cancers XWTT produced more quickiy Kith pipe and cigar smoke condensates than with cigarette smoke condensates. This suggests that the smoking 495-028 Q-73-15 581 of pipe and cigar tobaccos in the form of cigarettes does not alter the condensates to any significant degree. Davies and Day (32) prepared tars from small cigars especiallY manufactured from a composite blend of cigar tobacco representing small cigar ,bmnds smoked in the United Kingdom, cigarettes espe- cially manufactured from the same tobacco used for the cigars de- scribed above, and plain cigarettes especially manufactured from a composite blend of flue-cured tobacco representing the major plain cigarette brands smoked in the United Kingdom. The whole tar was dilut& to four concentration levels and applied to the shaved backs of female albino mice for their lifespan using four dosing regimens. A statistically significant increase in mouse skin carcinogenicity was shown with the cigar smoke condensate compared Kith the tars obtained from either flue-cured or cigar tobacco cigarettes. These results are consistent with those of the previously reported investigations. The effect of curing on carcinogenicity was examined by Roe, et al. (76). Bright tobacco grown in Mexico WIS either flue-cured or air- cured and bulk fermented. Both flue-cured and air-cured tobaccos were made into cigarettes standardized fordraT resistance and were smoked under similar conditions. Condensates from these cigarettes rrere ap- plied to mouse slain three times each \yeek in an acetone solution. The development of skin tumors was higher in mice treated with the flue- cured condensate than in mice treated with the air-cured condensate (P-lander (2~) exposed the upper trachea of nnesthetized cats to the snloke of cigarettes and cigars, ohsem-inc the etiect on ciliary acti\-ity through an incident-light microscope. -1 chemical analysis of the was and particulntc phases revealed that the cigar smoke was more alkaline and, in general, contained higher concentrations of isoprenr. acetone. acetonitrile, tolurne. and total particulate matter compared to cigarette smoke. The awrage number of puffs required to arrest ciliaq; activity was found to be X3 for the cigarette smoke and 11-1 for the cigar smoke. The difference is statisti- cally significant (P .prs of smoke. The frc- quency and duration of exposure rrcre not specific(l. x:d the cxtrnt of actual inhalation of smoke by the different qoups of rnts was either not determined or not reported. It is also diflicult to determine the effect of smoke exposure on the frequency and severity of respiratory infections when animals are exposed to smoke in groups where common exposure occurs. The rat strain used was not identified. but it. XIS noted that anim:& appeared to suffer from an endemic rat bron- chiectasis. It is not knon-n to what extent epidemics of respiratory infections occurred among these animals. Because of these difliculties, no firm conclusion cnn be drawn concerning the effect of smoking flue- cured or air-cured tobaccos on the incidence of respiratory infections in rats. TABLE 33.-hfortality ratios jor chronic obstructive pulmonary deaths in male cigar and pipe smokers. A summary of prospective epidtmio- logical studies Hammond aud Horn (40). DoU and Hill (es, 27). Best (9).----- Hammond (58) Kahn (60)--.- corn tot&l-_-_--_- ---- --.-_ .---- --..- .----------- Emphysema_- ______ I. 00 3. 33 .7.i - _.__ 5.85 _---.- Bronchitis--___--_-- 1.00 3.57 2. 11 _-___ Il.42 ______ COPDtotEL~~----- ---- ----- ----- --_-- _-__-__--___ Emphysema__--__-- 1.00 - ____ __--_ 1.37 `6.55 ______- Bronchitis._--.-_--_ .___ _____ ___-_ __-_- __--_-____-: COPD total_ _______ 1.00 79 Emphysema _____ -__ 1.00 1: 24 2.36 99 10.08 ___.__ 2. 13 1: 31 14. 17 ______ Bronchitis_--_---_-_ 1.00 1.17 1.28 1.17 4.49 ._____ 49SO28 S-73-16 589 Booeke (10).-e Pnrents of 59 femilies. Edwards, et 1,737 male al. (3s). outpstienta. Ashford, et 4,014 male d. (4). workers in 3 Scottish collieries. Bower (If)_-_ 95 male bank employees. Wynder, et al. 315 male pa- (114). tienta in New York and 315 male patient3 in California. Densen, et al. 5,287 tie Persistent cough- _ (24). p&d and Persistent 7,213 male aputum tramlit production. workers in Dyspne.... ______ . New York Wheeze ________ --_ City. Chest illness-_--~- 7 11 11 16 16 19 14 21 13 16 Cederlof, et 4,379 twin pairs, Cough- _ _ _ ___ __ __ 4 al. (18). au U.S. Prolonged cough-_- 2 veterans. Bronchitis- _ _ _ __ __ 2 Rimington 41,729 male (76). VOlUnteerS. Cagh ____________ Sputum production. Chest illness~-~~~~ Chronic bronchitis- 17 `19 Bronchitis--_----- 10 ' 35 21 37 Pneumoconiosi3_~_- 11 ' 34 14 2 Cough _____ - ______ sputum production. Wheeze--------__- Chest ilines_-__-- Cough (New York). Cough (California). Influenza (New York). Influenza (California). Cheat illness (New York). Chest illness (California). Chronic bronchitis_ 5 32 24 5 0 0 8 15 8 1.5 14 22 11 28 24 9 7 32 I .5 4 31 54 33 30 21 10 6 7 4 3 `9 48 ______ 20 ----__ 5 -____- 31 14 29 -___-- 33 _--_-_ 33 -_-___ 40 __-___ 56 51 67 66 24 -_.___ 31 ______ 12 ___.__ 11 ___--- 25 ______ 26 ___--- 26 ______ 32 --____ 18 _-____ 17 -_____ 11 ______ 10 ___--- 17 ___--- 590 TABLE 34.-Credence of req-iratoq symptoms and iUness by type of smokieontinued Camstock, et 670 male tele- Persistent cough.- 10 16 41 -____- al. (19). phone Per$stent 13 20 42 _-__-_ employees. sputum. Dyspnes ____ - ____ 33 39 44 -___-_ Chest illness in 14 18 20 ----__ pnst 3 years. Lcfcoc and 310 male phy- Chronic respira- 9 18 44 ---___ rTonnncott sicisns in tory disease. (69). London, Chronic bronchitis- 1 12 34 -__-__ Ontario. Obstructive lung 1 3 4 ______ disesse. Asthma-- ________ 7 3 6 __-_-- Rhonchi ._________ 0 3 9 ._____ TABLE S5.--Pulmonary junction L&U&S for cigar and pipe smokers as compared to nonsmokers FUIlCllOIl Ty-pe of moklng Non- Total pipe Clgarettt Mixed smoker and cigar OdY A&ford, et al. (4). Goldsmith, et al. (37). 3,311 active or retired longshore- men. Cornstock, et al. (19). Lefcoe and Wonnecott (69). 4,014 male workers in 3 Scottish collieria3. 670 male telephone employees. 310 male physicians in London, Ontsrio. FEV,.o--__-_m 3. 39 ' 2.59 3. 14 2. 62 Puffmeter ____ 313. 63 299. 26 303.44 - _____ FEV,.o .______ 2. 99 2. 80 2.91 __--_- TVC-_-__---- 3. 87 3. 68 3.88 ---___ -_ FEV,.e----e-e 3. 12 3. 26 2.82 ___-_- FEV,.o .______ 3. 39 3. 17 3. 11 ______ MSIFR liters 4. 09 4. 17 3.64 ______ per second. 591 GASTROISTEXTISAL DICOFCDERS Cigamtta smokers have an increased prevalence of peptic ulcer disease and a greater peptic ulcer mortaIity ratio thnn is found in nonsmokers. These relationships are stronkyr for gastric ulcer than for duodenal ulcer. Cigarette smoking a ppfars to reduce the elIectire- ne.ss of standard peptic ulcer treatment regimens and slob-s the rate of ulcer healing. Cigar and pipe smokers experience higher death rates from peptic ulcer disease than nonsmokers. These rates are higher for gastric ulcers than for duodenal ulcers but are somewhat less than those rates experienced by cigarette smokers. Table 31 presents the mortality ratios for ulcer disease in cigar and pipe smokers as reported in the prospective epidemiological studies. Retrospective or cross-sectional studies by Trovvell (.95), Allibone and Flint (2), Doll, et al. (2.9), and Edwards, et al. (39) contain data on ulcer disease in pipe smokers as well as cigarette smokers. So nssocintion was found betrreen pipe smoking and ulcer disease in these inrestigations. TABLE 36.-Aforta&Ly ratios for peptic ulcer disease in male cigar and p.pe smokers. Summary of prospective studies Type 01 smoking Hammond and Duodenal ulcer-_- _ _ _ 1. 00 0. 25 1. 67 _ _ . . . . 2. 16 ~. -. . - Horn (40). Doll and Hill Gastriculcer~.~.---- 1.00 _____ -_-.. 4.00 7.00 5. 30 (26, 27). Hammond (.?8)_- Gastric ulcer- __.____ 1. 00 ---- - -___- 2.04 2.93 . ..- -- Duodenel ulcer .____ - 1. 00 __-__ --..- .92 2.86 .----- Kahn (60) ______ Gastric ulcer--- _____ 1.00 2.90 2.84 2. 48 4. 13 ------ Duodenalulcer ._____ 1.00 1.58 1.59 1.39 2. 98 ------ Little Cigars In the past year, several new brands of little cigars (vveighing 3 pounds or less per 1,000) have appeared on the national market. These cigarette-sized products are manufactured, packaged, advertised, and sold in R manner similar to cigarettes. Little cigars enjoy several legal advantages over cigarettes: They have access to television ndvertising; they are taxed by the Federal Government and by most States, at much lower rates than cigarettes, resulting in a significant price advantage; 592 and they do not carry the rrnrning label required on cigarette pack- ages nnd in cigarette advertising. A market appears to be developing for the.se products, as there has recently been a sharp increase in the shipment of little cigars destined for domestic consumption (table 37). It is important to estimate the potentiai public health impact of these little cigars. An adequate epidemiological evaluntion of the ef- fect of little cigar smoking on health could take 10 or 15 years and is probably an impractical consideration; ho\rever, a review of the epide- mioIogicaI, autopsy, and experimental data concerning the health con- sequences of cigarette, pipe, and cigar smoking summarized in this and previous reports is helpful in considering the potential impact on health of smoking little cigars. An analysis of the chemical constit- uents suggests that both cigarettes and cignrs contnin similar corn- pounds in similar concentrations. TKO exceptions are reducing sugars, which nre not found in quantity in the fermented tobnccos commonly used in cigars, and the pH of the inhaled smoke. The pH of the smoke from U.S. commercial cigarettes is below 6.2 from the first to the Ia&. puff, mherens the smoke from the last half of a cigar may reach as high as pH 8 to 9. With increasing pH, nicotine is increasingly present in the smoke as the free base. Skin painting experiments in mice indicate that tumor yields with cigar or pipe "tars" are nearly identicnl with those obtained with cigarettes "tars". Tn addition, the epidemiological data suggest that depth of inhalat.ion probably accounts for the fact that cigarettes are so much more harmful than cigars and pipes in con- tributing to the development of lun g cancer, coronary heart disease, and nonneoplastic respiratory disease. For such diseases ns cancer of the oral cavity, larynx, and esophagus, where smoke from cigars, pipes, and cigarettes is available to the target organ at comparable levels, the mortality ratios are very similar `for all three forms of tobacco use. Several factors, including "tar," nicotine, and the pH of the smoke, probably operate to influence inhalation patterns of smokers. The relative contribution of individual factors to the inhalability of a tobacco product has not been determined. Smoking those brands of little cigars which can be inhaled by a significant portion of the population in a manner similar to the preg ent use of cigarettes would probably result in an increased risk of de- veloping those pulmonary and cardiovascular diseases which have been associated with cigarette smoking. On the other hand, smoking those little cigars which are used like most large cigars &ereby the smoke is rarely inhaled would probably result in lower rates of those Pulmonary and cardiovascular diseases than would bo found among cigarette smokers. OnIy a limited analysis is available comparing the chemical com- lmunds found in little cigars, cigarettes, and large cigars. The FTC analyzed t-he tar and nicotine content of all the little cigars (34) and cigarettes (97) currently available on the market. Little cigars have 593 generally a higher "tar" and nicotine level than cigarettes, although considerable o\-erlap results in some little cigar brands having "tar." and nicotine lerels comparable to those of some brands of cigarettes (fibs. 4 nnd j)- Hoffmann and IVynder (M) recently compared three brands of little cigaars \vith an unfiltfrcd cigarette, a filtered c@Ssrette, and a large cigar. They measured a number of smoke constituents, in- cluding: "tar," nicotine, carbon monoxide, carbon dioxide, reducing sugars, hydrogen cyanide, scetaldehyde, ncrolein, pyridines, phenols, bcnz(a)anthracene, and benzo(a)pyrene (table 32). Cigarette -1 XX the Kentucky reference cigarette, cignrette B was a popular brand of filter cigarette. Cigar A eras an 8.5 mm. little cigar, cigar I3 was an 8.5 mm. little cigar, cig.w C was a 95 mm. small cigar, and cigar D was a 112 mm. popular brand of medium sized cigar. The smoke pH ~a2 analyzed puff by puff (table 39). Cigarette smoke was found to be acidic (pH less than 7) for the entire cigar&a The smoke from little cigars became alkaline only in the last. puff or two, rrhereas about the last 40 percent of the puffs from the larger cigar were alkaline. Although the pH of the total condensate obtained from cigarettes is usually acidic and the total condensate obtained from cigars is usually alkaline, the above data indicate that smoke pH of tobacco products changes during the combustion process. Smoke from large cigars may be acidic during the first portion of the smoke and not become alkaline until the last half of the cigar is smoked. Brunnemann and Hoffmann (25), using the same techniques de- scribed above: examined the effect of 60 leaf constituents on smoke pH. For several wrieties of cigarette tobacco, they found a high correlation betlreen t.he total aklaloid and nitrogen content and smoke pH. Stalk position also affected smoke pH. Tobacco leaves near the top of the plant, n-hich contain high levels of tar and nicotine, yielded a smoke with a much higher pH than leaves lower on the plant. At present it is not known to ahat extent these factors influence the p1-I of the smoke of tobacws commonly used in cigars or how these kinds of pH changes inff uence the inhalability of tobacco smoke. The inhalation of smoke, however, appears to be the most important factor determining the impact a cigar will hare on overall health. Those physical and chemical characteristics of a tobacco product which most influence inhalation of tobacco smoke have not been accuratel_v determined. Severtheless, it appears likely that the smoke of some brands of cigars may be compatible rcith inhalation by a sig- nificant. portion of the smoking population. since: (a) Little cigars have tar and nicotine levels which, in some brands, are similar to the le\-ek found in cigarettes, and (6) the pH of Ihe smoke of some little cigar brands is acidic for the major portion of the little cigar and becomes alkaline only in the last puff or two. "tar" content. It is rea-sonable to conclude that smoking little cigars may result in health etfects similar to those associated \rith smoking cigarettes if little cigars are smoked in nmounts and with patterns of inhalation similar to those used by cigarette smokers, for the reasons cited abo\-e, and these additional reasons: (CZ) In those littlc cigars for which pre- liminary data are available, the concentrations of carbon monoxide, hydrogen cyanide, acetaldehyde, acrolein, pgridine, phenol, and poly- cyclic hydrocarbon levels are comparable to those found in cigarettes; (b) cigarette smoker; xho switch to cigars appear to be more likely to inhale cigar smoke than cigar smokers who have always smoked cigars (Id) ; and (c) cigarette smokers who switch to little cigars may he inclined to use them as they did cigarettes because of the physical similarities between the little cigars and cigarettes, including their size and shape, the number in a package, the burning rate, and the time it takes to smoke them. Figure 4.-Percent dlstrlbutmn of 130 brands of cigarettes and 25 brands of little cigars by I E - I Mg. "tar" 0 0 0 16.0 8.0 32.0 32.0 0 8.0 4.0 Cigarettts o-4 5-9 lo-14 15-19 m-24 25-29 30-s 35-39 40-44 45-49 Little Clgan 3.1 3.1 10.0 46.2 23.1 10.0 3.9 0.8 0 0 SOURCE; " s Deparfment 0, ".Df,h. Ed"cal,on, and w.t,are (97, and FKlarsl T,M. Commllrlan ,30. 595 Figure 5.-Percent distribution of 130 brands of cigarettes and 25 brands of little cigars by nicotine content. CigarFnesB Little cigars 5 cl SOURCE: U S. Department of Health. Education. and Welfare (977) and Federal Trada Corn. rr,,ss~on (34). 596 TABLE 37.~Shipment of small and [urge n'gars destined for domestic cons-umption (1970, 1971, 1970) Year lml 1971 1972 January _.____-_____ ~__- 58, 328, 520 85,733,750 123, 477, 550 February-_- .______ - ____ 63, 431,580 72,092,205 179,817,939 hiarch- _ _ _ __ __ _ __ __ ___ _ 85,881,860 46,542, 800 193, 165, 593 April _____ -_-_- _______._ 101,613,500 59,059,920 125, 335, 740 hlay ______ -_- __________ 81,093, 180 93,237,473 159, 334,565 June_________--_____-~- 82,471, 120 94,560,140 lSO,582,243 Subtotal _______ _ _ _ 472, 919, 760 451,246,313 966, 713, 530 - Jdg-_- --------_-_- -_-- 62, 143, 140 70, 332, 500 127, 713, 320 August ___.___________ ~_ 68,220,365 127, 709, 310 670,936,869 September.-__--_------- 79, 101,045 95,027, 340 422,534, 705 October ____________ ---_ 90,752,880 109,567,900 708, 116, 830 November- ___________ __ 64, 290, 600 106, 666, 107 551,326,888 December---.- _____ -___ 63,806, 010 123,809, 553 485,587,014 Subtotal _____ _ _ _ _ _ 428, 314,040 633, 112, 710 2,966,215,626 Yearly total._---__ 901,133, so0 1,054,359,028 3,932,929,156 Large cigars Janusry_~___-_~_-_-___- 581, 74'2,001 573,039, 120 534,565,488 February____-__.__-____ 595,249,522 586,810, 844 562, 414,577 March__---_-__-_~-__.~ 629, 977, 375 665, 998, 099 654,827,796 April ________ ____ _ ___ _ _ _ 652,800, 200 655, 213 850, 554,242,048 Mey~_~_~.~~~~_~~_____- 748, 040, 796 670, 933 064, 719,489,529 June__-_-______________ 649,539,031 692,436, 529 578, 501, 068 Subtotal _---______ 3,852,348,925 3, 844, 199,738 3, 604, 040, 506 JulY__--_______--______ 647, 397,547 619, 838, 386 Auwt -_-_________ - ____ 520, 873,339 673,082,971 148 September _________ - ____ 662,970, 682, 331,630 721,561,449 O~tobf2r- _ _ _ _ _ _ __ _ _ ____ _ 680,476,418 594,843, 957 968 November- 797,601,253 67.9, 420, 693,150,668 _ _ _ _ _ _ _ _ _ _ _ _ _ December--- -_ 696, 526,464 742,948,802 650, 746, 540 _______ __ 596,244, 159 516,879,415 437,429,996 Subtotal --_-____ -_ 4, 132, 413, 843 3, 902,534, 137 3,579,356, 130 Yearly total- __ _- _ E, 084,762, 768 7, 746,733,875 7,183,396,636 -: 0.8. Dwnmaant of the Tw (JOJ). 597 TABLE 3S.-Selected compounds in mainstream smoke "Tar", z~tiI~am prr cigarette.. _ Xicotine, milligram per cigarette- Carbon monoxide, volume per- cent_---~_-~_~---.----.-.-. Carbon dioxide, volume percent_- Reducing sugars, percent of tobacco Keight- _ __._____. ___ Hydrogen cJ-snide, microgram per cigarerle- _- - __.. ____. __ _ Aceteldchyde, micrrgram per cigarette-__-- ___._._.__ __-_- Acrolein. microgram per cigar- ette ____ - _______.______.____ Total pyridines, micrograms per clprertc_~---__-- ______-_-.. Phenol, microgram per cigarette-. Benz(a)anthrecene, nvnogrnm per cigererte--- ________.___. Benzo(a)pyrene, nanogram per cigarette _____ _ _ __ .__. _. . ___ _ 36. 1 2. 7 20. 3 1. 4 4. 6 4. 5 9. 4 9. 6 9. 3 7. 9 536.0 361. 0 iio. 0 774. 0 105.0 82. S 124.2 74. 0 47. 0 71. 0 27. 3 33. 0 31. 0 20. 0 17. 4 .G 5. 3 6. 5 1. 5 351.0 630. 0 41. 0 58. 0 35. 1 34. 0 18. 0 31. 3 40. 6 1. 8 3. 1 Il. 1 7. 7 13. 3 12. 7 2. 9 2. 7 G97. 0 1, 029. 0 I, 238. 0 1, 150. 0 54. 0 66. 0 85. 3 80. 3 63. 4 94. 1 25. 0 39. 0 22. 0 30. 0 Bourn: KoL7zann. D.. Wynder. E. L. C&l). TABLE SY?.--Th.e pH of the mainstream smoke of selected tobacco products [Ntmben In pruenthesu lndlcale number OZ last puff.1 .4wuga pE? Cl?xretle A C!garette B LllLl8 LIttIe 9mall Cigar D (nondlter) alwr1 cigar A cigar B ctgar c 3d puff----- 5th pufY_-_- 7th put?---- 9th puf-_-- 13th puff_-- 18th puff--- 23d pufi-T-e 28th puff_-- 33d PUB-_-- 38th puff_-- L-t puff--- G. 19 6. 14 6. 09 6. 02 _--_--_- - - _ - _ _ - - __- ____- ___--___ 5.96(11) 6. 15 6. 44 6. 12 6. 34 6. 01 7. 03 5.83 _.___.__ --______ --_-_--- _-_.-___ _-_-_--- ____--__ ___-_--- __--_--_ -______- 5. 76(10) 7.73 (8) 6. 55 6. 53 6. 46 6. 49 6. 51 6. 56 6. 98 6. 59 6. 47 ____-- .- 6. 27 6. 39 6. 41 6. 81 7. 22 7. 53 7. 78 7. QG(43) 8oarce: HoUmmn. D.. Wynder. E. L. (u). 598 Conclusions Pipe and cigar smokers in the United Stntes as n group experience overall mortality rntes that are slightiy higher than those of nonsmok- ers, but these rates are subs&ntially lower than those of cignrette smoker-s. This appears to be due to the fact thnt the total exposure to smoke that a pipe or cigar smoker receives from these products is relatively low. The typical cigar smoker smokes fexvcr than five cigars n day and the typical pipe smoker smokes less than 20 pipefuls a day. Most pipe and cigar smokers report that they do not inhale the smoke. Those who do inhale, inhale infrequently and only slightly. As a result, the harmful etfects of cigar and pipe smoking appear to be largely limited to incrensed death rates from cancer at thosesites which are exposed to the smoke of these products. Mortality rates from cancer of the oral cavity, intrinsic and extrinsic larynx, pharynx, and esophagus are approximately eq~ml in users of cigars, pipes, and ciga- rettes. Inhalation is evidently not necessary to expose these sites to tobacco smoke. Although these are serious forms of cancer. they account for only about 5 percent of the cancer mortality among men. Coronary heart disease, lung cancer, emphysema, chronic bronchitis, cnncer of the pancreas, and cancer of the urinary bladder are diseases Khich are clearly associated rrith cigarette smoking, but for cigar and pipe smokers death rates from these diseases are not greatly elevated above the rates of nonsmokers. These diseases seem to depend on rnod- erato to deep inhalation to bring the srnoke into direct contact with the issue at risk or to allow certain constituents, such as carbon mon- aside, to be systematically absorbed through the lungs or to affect the temporal patterns of absorption of other constituents such as nicotine thnt can be absorbed eit.her through the oral mucoza or through the lungs. Evidence from countries where smokers tend to consume more cigars and inhale them to R greater de.gree than in the United States indicates that rates of lung cancer become elevated to levels appronch- ing those of cigarette smokers. Available data on the chemical constituents of cigar, pipe, and ci@rette smoke su,azest that there are rnarked similarities in the cam:- position of these products Pipe and c&w smoke, however? tends to be more alkaline than cigarette smoke, and fermented tobaccos com- monly used in pipes and cigars contain less reducing sugars than the rapidly dried I-aricties commonly used in cigarettes. Experimental evidence suggests that little difference exists betxwzn the tumorigenic activities of tars obtained from cigar or cigarette 599 tobaccos. Malignant skin tumors n)>penr somewhat more mpidl>- and in larger number-s in animals whose skin has been painted with cigar tars than in those animals painted with cigarette tars. One must conclude that -some risk exists from smoking cigars nnd pipes as they ate currently used in the United States, but for most diseases this is small compwed to the risk of smoking cigarettes ns the.! nre commonly used. Keverthcless, changes in pntterns of usqy that would bring about increased exposure either through increased indi- vidual use of cigars and pipes or increased inhnlation of pipe and cigar smoke have the potential of producing risks not unlike those nom incurred by cigarette srrtokers. Mechanical or chemical modifications of pipe tobacco and cigars that would result in a smoke more compnt- ible with inhalation could have this efiect. Pipe and Cigar References (I) -bELry. T.. G5u 0. T. Relative risk ol pulmonary cancer in cigar and pip smokers. Cancer X)(8) : 1288-12x. August 1%7. (2) AUIBOSE. A.. FLISr. F. 3. Bronchitis, aspirin, smoking. and other factors in the aetiologY of peptic ulcer. Lancet 2: 179-182, July 28. 1958. (9) ARXIITAGE, -4. K.. `PLXXE~. D. M. Absorption of nicotine In cigarette and cigar smoke through the oral mucosa. Stature 22G(%~) : 123-1232. June 27, 1970. (4) A~HZY)RD. J. R., Baows. 5%. Dumtxo. D. P., SMITH. G. S.. PAY, J. 15'. J. The relation between smoking habits and physique, respiratory symy tams, rentilatorr function, and rndiological pneumoconiosis nmongst coal workers at three Scottish collieries. British Journal of Preventive and Social Medicine 15: 1W117, 1961. (5) AUERBACEI, 0.. Ha~ruoso, E. C.. Gannx~n, L. Histologic changes in the larytr in relation to smoking habits. Cancer25(1) : 92-104. Januar.r 1970. (6) AUEEBACH. 0.. Srour. A. P., HAMMOND. E. C., GARFIYKEL, L. Changes in bronchial epithelium in relation to sex, age. residence, smoking nnd pneumonia. Sew England Journal of Medicine ?67(3) : 111-119, July 19, l!XX. (7) AUERBACH. 0.. STOUT, A. P.. HAMMOND. E. C., GAHFISKEL, L. Histologic changes in esophagus in relation to smoking habits. -4rchires of Environ- mental Health ll( 1) : 4-15, July 1965. (8) AUERSACH. 0.. STOCT, A. P.. Ha~r~iox~, E. C., GARFISKEL, L. Smoking habits and age in relation to pulmonary changes. Rupture of alveolar sryt?lms. fibrosis and thickening of walls of small arteries and arterioles. Sew England Journal of Medicine 269(20) : 1045-10.54. Nov. 14. 1963. (9) BEST. E. W. R. -1 Canadian Study of Smoking and Health. Ottawa. Depart- ment of Sational FIenlth and.\Yelfare. 1%X, 137 pp. (IO) Boarcr IV. C. A studF of illness in a group of Cleveland families. S\`III. Tobacco smoking and respiratory infections. Sew England Journal of ltedicine 2.X+(:!) : 124.~~1249. Dec. 23. 1958 (II) BOWER. G. Respiratory symptoms and ventilatorr function In 172 ndults employed in a bank. American Review of ResplrntorF Diseases 83: ts&ao. 1961. 600