Loz

TaBiE 25.—Relative risk of cancer of the esophagus for men, comparing cigar, pipe, and cigarette smokers with nonsmokers.
A summary of retrospective studies

Relative risk ratio and percentage of cases and controls by type of smoking

 

 

Author, reference Number
Nonsmoker Cigaronly Pipeonly Total pipe Cigarette Mixed
and cigar only
Sadowsky, et al. (77): Relative risk......._._-- 1.0 4.8 3.8 5. 1 3.8 3.3
Cases._....----------------- 104 Percent cases____-__-_-- 4 5 8 6 60 18
Controls__.....__-.-..-.----- 615 Percent controls________- 13 3 7 4 53 19
Wynder, et al. (113): Relative risk._.._._.___- 1.0 3.1 2.1 -.---..-- 2.6 4
Cases___._.----------------.- 39 Percent cases___.....-_. 13 15 WW Ltt. 51 3
Controls___..._._--..-------.- 115 Percent controls__.__.--_- 24 9 160 LL eee 36 13
Pernu (73): Relative risk_....__..._- 10 _--.-- -- 3.0 .-.------ 2.7 5.9
Cases____._._------.-------- 202 Percent cases___..-.---- VW LL tee e-- 7 --------- , 59 18
Controls_.._...2.22-22 2 Lae 713 Percent controls._____--- 39) LLL § _Loeteeee 50 7
Schwartz, et al. (84): Relative risk_.....__.._. 10 _..-.-L_. 2.6 _.....--- 1.7 8.6
Cases___._._.--------------- 249 Percent cases. _.......-- 2 Jollee 2 Loewe eee &8 7
Controls_____._._---------.-- 249 Percent controls_____.__- | 7 Lee ee eee 67 7
Wynder and Bross (107): _ Relative risk.....------- 1.0 3. 6 9. 0 6. 0 28 3.7
Cases_.....-.-.-----.-------- 150 Percent cases.__..-.-..- 5 19 9 4 51 11
Controls___-_.__.-.---------- 150 Percent controls______~_-- : 15 16 3 2 55 9
c0z

TABLE 25-—Kelative risk of cancer of the esophagus for men, comparing cigar, pipe, and cigarette smokers with nonsmokers.
A summary of retrospective studies.—Continued

 

Relative risk ratio and percentage of cases and controls by type of smoking

 

 

Author reference Number
Nonsmoker Cigaronly Pipeonly Total pipe Cigarette Mixed
and cigar only
Bradshaw and Schonland (12): Relative risk... ___ | i | 4.8 _____L__ 2.3 1 LLL
Cases____--- we ene eee eee 117 Percent cases_..____.___ 1 Leelee 4.00 Lee 638 Le
Controls__......- 222-2 366 Percent controls_._.____. 8200 LL 1% LLL 58 Lee
Martinez (62): Relative risk__._..-._..- 1.0 2.0 --.----- 0 22 lle 1.5 2. 2
Cases_.._ 2-2-2 eee 120 Percent cases____.______ 8 9 Lele eee Lee 31 43
Controls.____._....-- 22 2 -_- 360 Percent controls________- 14 8 Llu eee ee LL _e 34 34
Martinez ! (63): Relative risk_..________- 1.0 2.0 28 1. 1.7 2.5
Cases_....-...-------------- 346 Percent cases__._.___._- 21 10 WH Lee 34 34
Controls_____..---.--------- 346 Percent controls_.______- 22 9 Lo Lele eee 36 25

 

! This study combines data for oral cancer and cancer of the esophagus.
Lung Cancer

Abundant evidence has accumulated from epidemiological, experi-
mental, and autopsy studies establishing that cigarette smoking is the
major cause of lung cancer. Several prospective epidemiological
studies have demonstrated higher lung cancer mortality ratios for pipe
and cigar smokers than for nonsmokers, but the risk of developing lung
cancer for pipe and cigar smokers is less than for cigarette smokers.
Table 26 presents a summary of these prospective studies. Dose-
response relationships such as those that helped demonstrate the nature
of the association between cigarette use and lung cancer could not be
as thoroughly studied for pipe and cigar smokers because of the rela-
tively few smokers in these categories. Although the number of deaths
were few, Doll and Hill (26) reported increased death rates from lung
cancer for pipe and cigar smokers with increasing tobacco consump-
tion (table 27). Kahn (80) also demonstrated a dose-response relation-
ship for lung cancer by the amount smoked (table 28).

A few of the retrospective studies contained enough smokers to allow
an examination of dose-response relationships for pipe and cigar smok-
ing and lung cancer (/, 61, 74, 77). An increased risk of developing
lung cancer was demonstrated with the increased use of pipes and
cigars as measured by amount smoked and inhalation. The retrospec-
tive investigation of Abelin and Gsell (7) is of particular interest. The
smoking habits of 118 male patients with cancer of the lung from a
tural area of Switzerland were compared with those reported in a sur-
vey of all male inhabitants of a town in the same region. About 20
percent of the population of this area were regular cigar smokers, the
most popular cigar being the Stiimpen, a small Swiss-made machine-
manufactured cigar cut at both ends with an average weight of 4.5 g.
In this investigation, cigar smokers experienced a risk of developing
lung cancer that was similar to the risk of cigarette smokers. A dose-
response relationship was demonstrated for inhalation and amount
smoked. These data suggest that the heavy smoking of certain cigars
may result in a risk of lung cancer that is similar to that experienced
by cigarette smokers.

Several pathologists have reported histologic changes in the
bronchial epithelium in relation to smoking in various forms. Knudt-
son (57) examined the bronchial mucosa of 150 lungs removed at au-
‘opsy and correlated the histologic changes noted with the history
of smoking, age, occupation, and residence. Specimens obtained from
the six cigar and pipe smokers demonstrated basal cell hyperplasia;
however, there was no squamous or atypical proliferative metaplasia
as 1s frequently seen in the heavy cigarette smokers.

Sanderud (78) examined histologic sections from the bronchial tree
of 100 male autopsy cases for the presence of squamous epithelial

203
metaplasia. In this study, 39 percent of the population were non-
smokers, 20 percent were pipe smokers, and 38 percent smoked cig.
arettes. A total of 80 percent of the pipe smokers and cigarette smokers
demonstrated squamous metaplasia of the bronchial tree, whereas only
54 percent of the nonsmokers had this abnormality.

Auerbach, et al. (6) examined 36,340 histologic sections obtained
from 1,522 white adults for various epithelial lesions including:
presence or absence of ciliated cells, thickness or number of cell rows,
atypical nuclei, and the proportion of cells of various types. The
pathologic findings in the bronchial epithelium of pipe and cigar
smokers are compared to those found in nonsmokers and cigarette
smokers (table 25). Pipe and cigar smokers had abnormalities that
were intermediate between those of nonsmokers and cigarette smokers,
although cigar smokers had pathologic changes that in some categories
approached the changes seen in cigarette smokers.

TapLE 26.—Mortality ratios for lung cancer deaths in male cigar and
pipe smokers. A summary of prospective studies

 

 

 

Type of smoking
Author, reference Non- Ci Pipe ‘Total pipe Cigarette Mixed —
smoker only, only and cfgar enly *
Hammond and Horn (40)- _—:1. 00 3. 35 8.50 _------- 23. 12 19. 71
Doll and Hill (26, 27)---- 1.00 --------  ------ 6.14 13.29 7. 43
Best (9)_.-_.----------- 1. 00 2.9 4.35 ._------ 14,91 _____...
Hammond (98)_--------- 1. 00 1. 85 2. 24 1.97 9. 20 7. 39
Kahn (60)_.------------ 1. 00 1. 59 1. 84 1.67 12.14 -_--___-

 

TaBLE 27.—Lung cancer death rates for cigar and pipe smokers by amount
smoked—Doll and Hull

 

 

Smoking type Death rate per 100 Number of deaths
Nonsmoker_-__.---------------------------- 0. 07 3
Cigar and pipe:

1 to 14 g. per day__-_------------------- . 42 12
15 to 24 g. per day._...----------------- . 45 6
>24 g. per day__--.-------------------- . 96 3
Cigarette only_.---------------------------- . 96 143

 

Source: Doll, R., Hill, A. B. (£6).

204
TABLE 28.—Lung cancer mortality ratios for cigar and pipe smokers by
amount smoked—Kahn

 

 

Smoking type Mortality ratio Number of deaths
Nonsmoker_____.-.-.-.._--__-_-_-_-_-_------ 1. 00 78
Cigar smokers:

<5 cigars per day_______._._-__--------- 114 12

5 to 8 cigars per day_______-_.-------.--- 2. 64 11

>8 cigars per day._.___-...-___._-_-___- 2. 07 2
Pipe smokers:

<5 pipefuls per day____.-._._-.-_._-___- 77 2

5 to 19 pipefuls per day_.__.-.._..-_-_.-- 2. 20 12

>19 pipefuls per day. ..--.----------.-.- 2. 47 3
Cigar and pipe:

8 or less cigars, 19 or less pipefuls__ _ ___-_-- 1. 62 18

>8 cigars, >19 pipefuls.........-______-_. 2. 19 2

 

Source: Kahn, H. A. (50).

205
90%

TABLE 29.-—Relative risk of lung cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A sum-
mary of retrospective studies

 

Relative risk ratio and percentage of cases and controls by type of smoking

 

 

Author, reference , Number
Nonsmoker Cigaronly Pipeonly Total pipe Cigarette Mixed
and cigar only

Levin, et al. (60): Relative risk... - 1.0 0.7 0.8 -2--2 8. 21 2 1-ooe
Cases___. 2-2 236 =©Percent cases___________ 15 11 140 Lele 66 _Lw Le
Controls____..-. 2.222222. 481 Percent controls_________ 22 23 25 Loe 44 Le
Schrek, et al. (81): Relative risk_..._.______ 1.0 .6 27 Lele 17 2 ie.
Cases_____-- 222-8 82 Percent cases._..__.____ 15 4 5 LLL 6h LLL ieee
Controls. __ 2.222222 ee 522 Percent controls_________ 22 23 Wo LL eeee 59 Lie
Wynder and Graham (111) Relative risk__....-_.___ 10 5.1 3.6 Llu. 15.7 .22 Lee
Cases.__. 2-2-2 605 Percent cases_____._____ 1 4 4 Lillie 91 Le
Controls... 222-22. 780 Percent controls______.__ 15 8 W200 Leelee 65 LLL
Doll and Hill (26): Relative risk_.-._...____ 10 222 lle 61 22 Le 9.6 _.- 2. LLL
Cases__----.2. 2222-2 _ ee 1,357 Percent cases_._____.___ 5 Lee nel 4 Lille 740 Le
Controls____.-..-.2- 2-2 eee 1,357 Percent controls._____.__ 5 Leanne nee 7 wont a lene 69 Lele
Koulumies (56): Relative risk____________ L0 _- 2 LLL. 9.6 22-2 Le 29.3 --. 2 LL
Cases__._ 22 812 Percent cases___________ 6 _---- Le 2 Leet i
Controls__. 2-2 2-8. 300 ~=Percent controls_________ 18 LLL. 6 Lule lle 7 eee
Sadowsky, et al. (77): Relative risk_..______._- 1.0 2.4 14 -12. lle 3.7 5.6

Cases. ..-__-_- 22-22 477 =‘ Percent cases___________ 4 2 3 Lele 57 31

Controls_.-..- 2. ee 615 Percent controls_________ 13 3 (re 53 19
£07

Wynder and Cornfield (110):

Mills and Porter (66):
Cases_.__.-. 2222 eee
Controls___...----- 2-2-2 ee 1, 588

Schwartz and Denoix (82):

Lombard and Snegireff (61):

484

2,101
Controls___---_--.--------_.-- 5, 960

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 -- 222-2. Leelee
To teeee eee 2 ae eee

3100 Leelee Lene
10 --------- 22 eee
ne

280 Lee ene
1.0 --.------ 4.7
) ene 6

VW Ll 14
10 ----- 2 Le 3. 1
2 2 --.e-e 9

9 _LLL-Leee 13
10 2-2 eee lle.
2 penne eee oon
WO Lee eee L eee
10 --------- 4.2
To Looe en--- 4

39 eile 5
807%

TaBLE 29.—Relative risk of lung cancer for men, comparing cigar, pipe, and cigarette smokers with nonsmokers. A sum-
mary of retrospective studies—Continued

 

Relative risk ratio and percentage of cases and controls by type of smoking

 

 

Author, reference Number
Nonsmoker Cigaronly Pipeonly Total pipe Cigarette Mixed
and cigar only

Wicken (106): Relative risk_......._-_- a 2.2 4.3 4.2

Cases_______- eee 803 Percent cases________-_- 40 lle eee Lele 10 78 7

Controls...._.-.._...--.------- 803 Percent controls__.___-_- 140° _Llee eee Lee 16 64 6
Abelin and Gsell (1): Relative risk_._..__-_--- 1.0 30. 7 21.8 39. 9 31.0 24.7

Cases__.--_._-_-_------------- 118 Percent cases___._.----- 2 28 7 58 25 24

Controls...._..__._....-------- 524 Percent controls. ___----- 35 19 6 31 7 10
Wynder, et al. (116): Relative risk__..__.--_-- 10 _-.------ ---.---- 2.0 12.4 ___ LL.
Cases_.._-.._----------------- 210 Percent cases. _-_------- 8 _Leee---- o-e eee 5 92 _____ue.

Controls____..__..----_.------- 420 Percent controls.__------ 210 lve eee Lone 15 47

 
60%

TaBLE 30.—Changes in bronchial epithelium of male cigar, pipe, and cigarette smokers as compared to nonsmokers

 

Percent sections Percent 3 plus

Percent

Percent

 

Group Number of Sections with with epithelial cell rows With atypical cells Total hyperplasia and
subjects epithelium lesions e present sections goblet cells in
glands
Ist set (none vs. pipe vs. cigarette—matched
on 1:1 basis):
Nonsmoker.._....-.._-_.__-.---_---___- 20 985 21.7 11.2 2. 6 1, 031 10. 3
Pipe only__-._--.---. 2 e eee 20 924 65. 5 38. 1 37.0 979 35. 9
Cigarette only... 2.22 eee 20 914 96. 8 88. 6 95. 2 982 72.1
2d set (none vs. pipe vs. cigarette—matched
on frequency basis) :
Nonsmoker___.-.___.-__--____-___--- oe. 25 1, 246 22.9 13.4 7 1,277 11.5
Pipe only___-_. 2.222 eee 25 1, 164 68. 7 38. 7 38. 2 1, 247 37.9
Cigarette only... 22-2222. 25 1, 126 96. 3 88. 7 89. 5 1, 237 75.5
3d set (none vs. cigar vs. cigarette) :
Nonsmoker..______.-_.--_.----_.-_____ 35 1, 706 27. 4 12.7 8 1, 748 15. 3
Cigar only._._.-_--2 22-2 ee 35 1, 733 90. 8 40. 0 73. 6 1, 828 52. 5
Cigarette only__ 22-22 35 1, 526 99. 0 92. 7 97.8 1, 693 80. 2

 

Source: Auerbach et al. (6).
Tumorigenic Activity

The tumorigenic activity of tobacco smoke can be modified in both a
quantitative and qualitative sense. Physical or chemical changes in
tobacco that result in a reduction of total particulate matter upon
combusion of a given quantity of tobacco may result in a reduction
of carcinogenic potential. 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 when tobacco is
pyrolized at temperatures higher than 700° centigrade (34).

Cigars, pipes, and cigarettes are similar in that they are smoked ~
orally and have a common site of introduction to the body. The tissues
of the mouth, larynx, pharynx, and esophagus appear to receive ap-
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 smoke condensates obtained
from cigarettes, cigars, and pipes. Most. of these studies were standard.
ized in an attempt to make the results of the cigar and pipe experiments
more directly comparable with the cigarette data and most used the
shaved skin of mice for the application of tar. Tars from cigars, pipes.
and cigarettes were usually applied on an equal weight basis so that
qualitative 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
animals from the high concentrations of nicotine frequently found in
these products.

210
Wynder and Wright (117) examined the differences in tumorigenic
activity of pipe and cigarette condensates. Tars were obtained by the
smoking of a popular brand of king-size cigarettes and the same ciga-
rette tobacco smoked in 12 standard-grade briar bow] pipes. Both the
cigarettes and pipes were puffed three times a minute with a 2-second
puff and a 35-ml. volume. Both the cigarettes and pipes attained similar
maximum combustion zone temperatures; however, the use of cigarette
tobacco in the pipe resulted in a combustion chamber temperature that
averaged about 150° centigrade higher than temperatures achieved
when pipe tobacco was used. Chemical fractionation was accomplished
and equal concentrations of the neutral fraction were applied in three
weekly applications to the shaved skin of CAF, and Swiss mice. The
results indicate that 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 were obtained in both the CAF,
and the Swiss mice, and the latent period was about 2 months shorter.

Extending these data, Croninger. et al. (20) examined the biologic
activity of tars obtained from cigars. pipes, and cigarettes. Each form
of tobacco was smoked as it was manufactured in a manner to simulate
human smoking or to maintain tobacco combustion. The whole tar was
applied in dilutions of one-to-one and one-to-two with acetone to the
shaved backs of female CAF, and female Swiss mice using three
applications each week for the life-span of the animal. The nicotine was
extracted from the pipe and cigar condensates to reduce the acute
toxicity of the solutions. The Swiss mice. pipe. cigar. and cigarette 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 were reported by Kensler (52) who applied conden-
sates obtained from cigars and cigarettes to the shaved skin of mice.
The incidence of papillomas produced by cigar smoke concentrate was
no different from that of the cigarette smoke condensate. Similarly,
there was no difference between ci gar and cigarette smoke condensates
when carcinoma incidences were compared,

Homburger, ct al. (45) prepared tars from cigar, pipe, and cigarette
tobaccos that were smoked in the form of cigarettes. In this way, all
tobaccos were smoked in an identical manner and uniform combustion
temperatures were achieved. Because of this standardization, differ-
*nees in tumor yield could be attributed to tobacco blend and not the
Manner in which the tars were prepared. The whole tars were diluted
one-to-one with acetone and applied to the shaved skin of CAF, mice
three times a week for the lifespan of the test animal. Skin cancers
Were produced more quickly with pipe and cigar smoke condensates
than with cigarette smoke condensates, This suggests that the smoking

15

 

495-028 O—73
213
of pipe and cigar tobaccos in the form of cigarettes does not alter the
condensates to any significant degree.

Davies and Day (22) prepared tars from small cigars especially
manufactured from a composite blend of cigar tobacco representing
small cigar brands 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
diluted 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 with 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 was either flue-cured or air-
cured and bulk fermented. Both fiue-cured and air-cured tobaccos were
made into cigarettes standardized for draw resistance and were smoked
under similar conditions. Condensates from these cigarettes were ap-
plied to mouse skin three times each week 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<0.01). The difference may have been due to the use of equal
weights of condensate rather than the use of extracts from an equal
number of cigarettes. The air-cured cigarettes produced a greater
weight of condensate than did the flue-cured cigarettes. A chemical
analysis of the two tobaccos and two condensates revealed only small
differences in composition. Evidently air curing of Bright tobacco
in the method used is not associated with a loss of reducing sugars.

A more detailed analysis of these experimental studies is presented
in table 31.

These experimental data suggest that cigar and pipe tobacco con-
densates have a carcinogenic potential that is comparable to cigarette
condensates. This is supported by human epidemiological data for
those sites exposed equally to the smoke of cigars, pipes. and cigarettes.
The partially alkaline smoke derived from pipes and cigars is gen-
erally not inhaled, and as a result there appears to be a lower level
of exposure of the lungs and other systems to the harmful properties of
pipe and cigar smoke than occurs with cigarette smoking. It is antic-
ipated that modifications in pipe tobacco or cigars which would result
in a product that was more readily inhalable would eventually result
in elevated mortality from cancer of the lung, bronchitis and emphy-
sema, arteriosclerotie cardiovascular diseases, and the other condi-
tions which have been clearly associated with cigarette smoking.

212
£12

TABLE 31.—Tumorigenic activity of cigar, pipe, and cigarette smoke condensates in skin painting experiments on animals
[Key: A=Method. B=Frequency. C=Duration. D=Material.]

Percent
Author, reference Animal Activity Treatment Number

a
Papillomas Carcinomas

Wynder and CAF, and A. Painting shaved skin. CAF;:
Wright Swiss mice. B. 3 times a week. Pipe (cigarette tobacco)_____. 30 60 20
(117). C. Lifespan (24 months). Cigarette... 222 30 30 3
D. Neutral fraction tar from Swiss:
cigarettes and cigarette Pipe (cigarette tobacco) ______ 30 63 50
tobacco smoked in pipes. Cigarette... 30 63 33
Croninger, et Female Swiss A. Painting shaved skin. Cigar, nicotine free (1:1)_._____ 46 65 41
al. (20). mice. B. 3 times a week. Pipe, nicotine free (1:1).__.____ 45 71 44
C. Lifespan. Cigar (1:2)-._- 22228 78 33 18
D, Whole tar diluted in Pipe, nicotine free (1:2)___.____ 89 30 16
acetone. Cigarette (1:1)_._-____.. Ll. 86 47 37
Acetone controls. _.__________. 23 0 0
Kensler (6%)__. Swiss mice_____. A. Painting shaved skin. Cigar tar (J) 100 mg. per week_. 100 42 41
B. 3 times a week. Cigarette tar (G) 100 mg. per 100 40 28
C. Lifespan. week.
D. Whole tar diluted in Cigarette tar (E) 100 mg. per 100 34 34
acetone. week,
Fle

TaBLE 31.—Tumorigenic activity of cigar, pipe, and cigarette smoke condensates in skin painting

experiments on animals—Continued

[Key: A=Method. B= Frequency. C=Duration. D=Material.]

 

Percent
Author, reference Animal Activity Treatment Number ———-—-——--—----—--
Papillomas Carcinomas
Homburger, et CAF, mice------ A. Painting shaved skin. Cigar tobacco cigarettes ! 65 mg. 100 37.5 19
al. (48). B. 2 to 3 times a week. per week.
C. Lifespan (2 years). Pipe tobacco cigarettes | 64 mg. 100 23 20
D. Whole tar diluted 50 per- per week.
cent in acetone. Cigarettes | 62 mg. per week- --- 100 15 23
Acetone controls___~---------- 100 0 0
Davies and Female albino A. Painting shaved skin. Cigars, small 83 mm. long 150 144 44 27
Day (22). mice. B. Varied. per week.
C. 116 weeks. Cigar tobacco cigarettes 150 72 32 14
D. Whole tar in 150 mg. per week.
acetone. Cigarettes 150 per week_------- 144 28 13
Roe, et al. Female Swiss A. Painting shaved skin. Flue-cured Bright tobacco 180 400 52 30
(76). mice. B. 3 times a week. mg. per week.
C. Lifespan. Air-cured Bright tobacco 180 400 68 23
D. Whole tar diluted in mg. per week.
acetone. Acetone controls 0.75 cc. per 400 L.3 0.5

weck.

 

1 Cigar, pipe, and cigarette tobacco smoked as cigarettes at similar combustion temperatures.
CARDIOVASCULAR DISEASES

The majority of deaths in the United States each year are due to
cardiovascular diseases. Cigarette smoking has been identified as a
major risk factor for the development of coronary heart disease
(CHD). However, pipe and cigar smokers experience only a small
increase in mortality from coronary heart disease above the rates of
nonsmokers. Cigarette smokers have higher death rates from cerebro-
vascular disease than nonsmokers, whereas pipe and cigar smokers have
cerebrovascular death rates that are only slightly above the rates of
nonsmokers. Table 32 summarizes the major prospective epidemiologi-
cal investigations that examined the association of smoking in various
forms and total cardiovascular diseases, coronary heart. disease. and
cerebrovascular disease. Doll and Hill. (28), Best (9), and Kahn (50)
examined dose-response relationships for pipe and cigar smokers and-
reported a slight increase in mortality from coronary heart disease
with an increase in the number of cigars or pipefuls smoked.

Other prospective epidemiological studies have also examined the
relationship of smoking in various forms to coronary heart disease and
related risk factors. Jenkins, et al. (49) in the Western Collaborative
Group Study of coronary heart disease, reported an incidence of coro-
nary heart disease in men aged 50 to 59 who were pipe and cigar smok-
ers that was intermediate between the rates seen in cigarette smokers
and nonsmokers. No increase in incidence of coronary heart disease was
seen among the pipe and cigar smokers in the younger age groups.
Shapiro, et al. (85), in a study of the health insurance plan (HIP)
population, reported incidence rates for myocardial infarction, angina
pectoris, and possible MI, in pipe and cigar smokers that. were similar
to the incidence rates seen in cigarette smokers. These rates were con-
siderably higher than those of nonsmokers. Data from the pooling
project (47) suggested that the incidence of CHD deaths, sudden
death, and the first major coronary event in pipe and cigar smokers
was intermediate between the incidence experienced by cigarette smok-
ers and nonsmokers. In contrast to these. studies, Doyle, et al. (30)
reported no increase in CHD deaths, myocardial infarction, or angina
pectoris in pipe and cigar smokers over the rates of nonsmokers in the
Framingham study.

The retrospective studies of Mills and Porter (64), Villiger and
Heyden-Stucky (104), Schimmler, et al. (80), and Hood, et al. (46)
contained data suggesting that pipe and cigar smokers experience
mortality rates from coronary heart disease that are essentially similar
to those experienced by cigarette smokers. The retrospective study of
Spain and Nathan (86) reported lower rates of coronary heart, dis-
ease in all smoking categories than were found in nonsmokers.

Van Buchem (103) and Dawber, et al. (23) examined serum choles-
terol levels in groups of individuals classified according to smoking

215
habits. In these two studies, pipe and cigar smokers had serum choles.
terol levels that were nearly identical with the levels found in
nonsmokers.

Tibblin (97) and Dawber, et al. (23) investigated the effect of smok-
ing on blood pressure. The proportion of smokers decreased in groups
with higher blood pressures, although this was not as dramatic for
pipe and cigar smokers as it was for cigarette smokers.

In an experimental study using anesthetized dogs, Kershbaum and
Bellet (54, 55) examined the effects of inhaled and noninhaled ciga-
rette, cigar. and pipe smoke on serum free fatty acid levels and urinary
catecholamine and nicotine excretion. In this study, inhalation of to-
bacco smoke from all these sources resulted in similar increases in
serum free fatty acids and in catecholamine and nicotine excretion.

TABLE 32.—Mortality ratios for cardiovascular deaths in male cigar and
pipe smokers. A summary of prospective epidemiological studies

 

 

 

Type of smoking
Author, reference Category
Non- Cigar Pi Total Ciga-
smoker only only pipe and rette only Mixed
cigar

Hammond and Cardiovascular 1.00 1.26 1.07 _____- 1.57 __LL_.
Horn (40). total.

Coronary._-_------- 1.00 1.28 1.03 ___.-- 1.70 _____.

Cerebrovascular. - . _- 1.00 1.31 1.23 _____. 1.30 __L__.

Doll and Hill Cardiovascular 1.00 _.--. _-_--- 0.99 1.26 1.13
(26, 27). total.

Coronary___..------ 1.09 _---. ------ .94 1.23 118

Cerebrovascular -___- 1,00 __--. -___-- -95 1.18 97

Best (9)_..-_-_- Cardiovascular 1.00 1.14 .95 _____. 1.52 __ LL.
total.

Coronary__.-------- 1.00 .99 1.00 _-___- 1.60 _____-

Cerebrovascular. ____ 1.00 1.28 .85 _____- .88 _____-

Hammond ! Cardiovascular 1.00 __... _--__- 1.06 1.90 _____.
(38). total.

Coronary.._-------- 1.00 1.385 1.19 _____- 1.84 1.58

Cerebrovascular-___- 1.00 ____-_ ___-_- 1.09 1,41 1. 40

Kahn (50)______ Cardiovascular 1.00 1.05 106 1.05 1.75 _____.
total.

Coronary. ._-------- 1.00 1.04 1.08 1.05 1.74 _____-

Cerebrovascular... - 1.00 1.08 1.09 1.06 1.52 _____-

 

1 Mortality ratios for ages 55 to 64 only are presented .

Curoxtc OsstrectTive PutMonary Disease (COPD)

Chronic bronchitis and pulmonary emphysema account for most of
the morbidity and mortality from chronic respiratory disease in the
United States. Cigarette smokers have higher death rates from these

216
diseases and have more pulmonary symptoms and impaired pul-
monary function than nonsmokers. Cigarette smokers also have more
frequent and more severe respiratory infections than nonsmokers.
The relationship between smoking pipes and cigars and these diseases
is summarized in this chapter. The major prospective epidemiological
studies are summarized in table 33.

In a retrospective study of 1,189 males and matched controls in
Northern Ireland, Wicken (706) investigated smoking in various
forms and mortality from bronchitis. The relative risk ratios com-
pared to nonsmokers for mortality from chronic bronchitis were 1.98
for all smokers, 1.55 for pipe and cigar smokers, 2.25 for cigarette
smokers, and 1.49 for mixed smokers.

From a review of these prospective and retrospective studies, it
appears that pipe and cigar smokers experience mortality rates from
bronchitis and emphysema that are higher than the rates of non-
smokers. Although these morality rates approach those of cigarette
smokers, in most instances they are intermediate between the rates
of cigarette smokers and nonsmokers.

Pipe and cigar smokers have significantly more respiratory symp-
toms and illnesses than nonsmokers. Those studies which contain data
on pipe and cigar smoking as related to respiratory symptoms are
summarized in table 34.

Only a few studies have examined pulmonary function in pipe and
cigar smokers. There appears to be little difference in pulmonary funce-
tion values for pipe and cigar smokers as compared to nonsmokers
(table 35).

Naeye (67) conducted an autopsy study on 322 Appalachian coal
workers who were classified according to the type of coal mined and
tobacco usage. Emphysema was slightly greater in cigarette smokers,
as were anatomic evidences of chronic bronchitis and bronchiolitis.
Those changes found in pipe and cigar smokers were intermediate
between those of cigarette smoking miners and nonsmoking miners.

Changes in pulmonary histology in relation to smoking habits and
age were examined by Auerbach, et al. (8). Fibrosis, alveolar rupture,
thickening of the walls of small arteries, and thickening of the walls
of the pulmonary arterioles were found to be highly related to the
smoking habits of the 1,340 male subjects examined. The 91 pipe and
cigar smokers over the age of 60 were found to have somewhat more
alveolar rupture than the men of the same age distribution who never
smoked regularly. However, pipe and cigar smokers as a group had
far less rupture than cigarette smokers, The same relations as described
above were found for fibrosis, thickening of the walls of the arterioles
and small arteries, and padlike attachments to the alveolar septums.

Tobacco smoke has been shown experimentally to have a ciliostatic
‘flect on the respiratory epithelium. The interval between puffs, the

217
amount of volatile and particulate compounds in the smoke, and the
exposure volume have been shown to influence the toxic effect of
tobacco smoke. Dalhamn and Rylander (2/7) exposed the upper trachea
of anesthetized cats to the smoke of cigarettes and cigars, observing
the effect on ciliary activity through an incident-light microscope.
A chemical analysis of the gas and particulate phases revealed that
the cigar smoke was more alkaline and, in general, contained higher
concentrations of isoprene, acetone, acetonitrile, toluene, and total
particulate matter compared to cigarette smoke. The average number
of puffs required to arrest ciliary activity was found to be 73 for the
cigarette smoke and 114 for the cigar smoke. The difference is statisti-
cally significant (P <0.01). Of the two smokes, the smoke with the
highest concentration of volatile compounds was found to be the least
ciliostatic. This suggests that the degree of ciliotoxicity of a smoke is
not necessarily correlated to the level of one or several of the substances
found in the smoke.

Passey, et al. (70. 71, 72) studied the effect of smoke from flue-cured
cigarette tobacco cigarettes and air-cured cigar tobacco cigarettes on
the respiratory system of rats. In two separate but similar experi-
ments, a total of 48 animals were exposed to English cigarette tobacco
smoke, 48 were exposed to air-cured cigar tobacco smoke, and 12 were
exposed to an air-cured Burley tobacco smoke. The rats in groups were
exposed to the specific smoke in a smoke-filled cabinet. Animals ex-
posed to the smoke from air-cured tobaccos remained healthy through-
out. the experiments, even at high levels of smoke exposure. The three
deaths that occurred within this group were from nonrespiratory
causes. In both experiments, the rats exposed to cigarette tobacco smoke
began to die within 1 or 2 months, and in each experiment most of the
animals died within a week or two of the first deaths. At autopsy the
rats exposed to flue-cured tobacco smoke on gross examination were
found to have greatly enlarged lungs, the trachea was often full of
mucus, and there was evidence of pneumonia. On microscopic examina-
tion it was found that the trachea and bronchi contained purulent
cellular exudates. evidence of metaplastic changes, an absence of cilia,
and goblet cell hpyerplasia. Typically. the cause of death was a lobar
or bronchopneumonia. The author concluded that, “the smokes of flue-
cured tobaccos are more dangerous to man and to animals than those
of air-cured tobaccos.”

218
Unfortunately, few details were published concerning the method
used to expose the animals to the different types of smoke. The fre-
quency and duration of exposure were not specified, and the extent of
actual inhalation of smoke by the different groups of rats was either
not determined or not reported. It is also difficult 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 was
noted that animals appeared to suffer from an endemic rat bron-
chiectasis. It is not known to what extent epidemics of respiratory
infections occurred among these animals. Because of these difficulties,
no firm conclusion can be drawn concerning the effect of smoking flue-
cured or air-cured tobaccos on the incidence of respiratory infections
in rats.

TABLE 33.—Mortality ratios for chronic obstructive pulmonary deaths
in male cigar and pipe smokers. A summary of prospective epidemio-
logical studies

 

 

 

Type of smoking
Author, reference Category
Non- Cigar Tipe Tota) Ciga-
smoker only only pipe and rette only Mixed
cigar

Hammond and COPD total_.______ 1.00 129 1.77 _____ 2.85 ._____
Horn (40). Emphysema_____--. _.-. ----- ----- @- ee ee.
Bronchitis_---..-..-. 222 2222. Lee. Lee ee.
Doll and Hili COPD total___-...2 2-22 ©, lee ee ee.
(26, 27). Emphysema___-.--. _... _-.-. 222-2 ___-. __ ee
Bronchitis__________ 1.00 _---. _L_Le 4.00 7.00 6.67
Best (9)________ COPD total__...2-. _22. eee Lee Le.
Emphysema__-_.____ 1.00 3.33 .75 _____ 5.85 _.-2_
Bronchitis__________ 1.00 3.57 2.11 _.___ 11.42 ___Lo.
Hammond (38)... COPD total..___.-. ___. __._. ©... 22. 2
Emphysema. .______ 1.00 __-... LL. 1.37 16.55 ._____
Bronchitis-...-...-. ~22. 2-2. ole. Lee
Kahn (60) ______ COPD total________ 100 .79 2.36 .99 10.08 ______
Emphysema_._-______ 100 1.24 2.13 1.31 14.17 _____.
Bronchitis__________ 1.00 1.17 1.28 1.17 4.49 ______

 

! Only mortality ratios for ages 55 to 64 are presented.

495-028 O—73—_16

219
TasLe 34.—Prevalence of respiratory symptoms and illness by type of

 

 

 

smoking
Percent prevalence
Author, reference Number and type of Tiness
population Non- Total Ciga-
smoker pipe and rette Mixed
cigar only
Boake (10)... Parents of 59 Cough_____.------ 32 32 48 ______
families. Sputum 24 15 20 _____.
production.
Chest illness_._._- 5 4 5 Lule.
Edwards, et 1,737 male Chronie bronchitis_ 17 119 31 14
al. (38). outpatients.
Ashford, et 4,014 male Bronchitis_______- 10 «135 21 37
al. (4). workers in 3. Pneumoconiosis....60 11 134 14 2
Scottish
collieries.
Bower (11)... 95 male bank Cough..._._-_---- 0 0 29 _____.
employees. Sputum 8 15 33 __o
production.
Wheeze___._-_-_.-- 8 31 33 _____.
Chest illness____-_- 15 54 40 __L__.
Wynder, etal. 315 male pa- Cough (New 14 33 56 51
(114). tients in York).
New York Cough 22 30 67 66
and 315 male (California).
patients in Influenza (New il 21 24 _____.
California. York).
Influenza 28 24 31 _.__L.
(California).
Chest illness 9 10 12 _.LLL.
(New York).
Chest illness 7 6 V1 LLL.
(California).
Densen, et al. 5,287 male Persistent cough- - 7 ll 25 __.---
(24). postal and Persistent 11 16 26 _____-
7,213 male sputum
transit production.
workers in Dyspnea__._.----- 16 19 26 ____--
New York Wheeze....-.----- 14 21 32 ____--
City. Chest illness__- ~~ - 13 16 18 ___.--
Cederlof, et 4,379 twin pairs, Cough_.--------- 4 7 17 ___---
al. (18). all U.S. Prolonged cough. -- 2 4 11 ___.--
veterans. Bronchitis -—.------ 2 3 10 __.---
Rimington 41,729 male Chronic bronchitis - 5 19 17 __----
(76). volunteers.

220
TaBLE 34.—Prevalence of respiratory symptoms and illness by type of

 

 

 

smoking—Continued
Percent prevalence
Author, reference Number and type of Illness
population Non- Total Ciga-
smoker pipe and rette Mixed
cigar only
Comstock, et 670 male tele- Persistent cough._ 10 16 41.2 LL.
al. (19). phone Persistent 13 20 42 _____.
employees. sputum.
Dyspnea________. 33 39 44 _____.
Chest illness in 14 18 20 _____.
past 3 years.
Lefeoe and 310 male phy- Chronic respira- 9 18 44
Wonnacott sicians in tory disease.
(69). London, Chronic bronchitis. 1 12 34 _____.
Ontario. Obstructive lung 1 3 4 LLL
disease.
Asthma__________ 7 3 6 _-___.
Rhonchi_________. 0 3 9 LLL

 

1 Figures for pipe only.

TaBLE 35.—Pulmonary function values for cigar and pipe smokers as
compared to nonsmokers

 

 

 

 

Type of smoking
Author, reference Number and type Function
of population Non- Total pipe Cigarette Mixed
smoker and cigar only

Ashford, et 4,014 male FEV, ,9_--.__- 3.39 12.59 3.14 2.62
al. (4). workers in

3 Scottish
collieries.

Goldsmith, 3,311 active Puffmeter____ 313.63 299.26 303.44 __.___
et al. (37). or retired FEV} .9---.__- 2. 99 2. 80 2.91 ______

longshore- TVC_._______ 3. 87 3. 68 3.88 ______
men.

Comstock, 670 male FEV; .9-.---_- 3, 12 3. 26 2.82 _ 2.
et al. (19). telephone

employees.

Lefeoe and 310 male FEV, 9_.-____ 3. 39 3.17 3.11 22.
Wonnacott physicians MMFR liters 4.09 4.17 3. 64 ___2__
(69). in London, per second.

Ontario.
' Figures for pipe only.

221
GASTROINTESTINAL DISORDERS

Cigarette smokers have an increased prevalence of peptic ulcer
disease and a greater peptic ulcer mortality ratio than is found in
nonsmokers. These relationships are stronger for gastric ulcer than
for duodenal ulcer. Cigarette smoking appears to reduce the effective-
ness of standard peptic ulcer treatment regimens and slows 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 Trowell (95), Allibone
and Flint (2), Doll, et al. (29), and Edwards, et al. (33) contain
data on ulcer disease in pipe smokers as well as cigarette smokers. No
association was found between pipe smoking and ulcer disease in these
investigations.

TaBLE 36.—Mortality ratios for peptic ulcer disease in male cigar and
pipe smokers. Summary of prospective studies

 

Type of smoking

 

 

Author, reference Tliness Total Ciga-
Non- Cigar Pipe pipe rette Mixed
smoker only only and only
cigar
Hammond and Duodenal ulcer_.-.-- 1.00 0,25 1. 67 _----- 2.16 _._..-
Horn (40).
Doll and Hill Gastric ulcer__------ 1.00 _...-  ----- 4.00 7.00 5.30
(86, 27).
Hammond (38)__ Gastric ulcer_-_----- 1.00 _-.-- ----- 2.04 2.95 .-_-_-
Duodenal ulcer_-_..- 1.00 ----- ----- .92 2.86 __----
- Kahn (50)_----- Gastric ulcer__..--.. 1.00 2.90 2.84 2.48 4.13 -__-_-
Duodenal ulcer--_---- 1.00 1.58 1.59 1.39 2.98 _-_.--

 

Little Cigars

In the past year, several new brands of little cigars (weighing 3
pounds or less per 1,000) have appeared on the national market. These
cigarette-sized products are manufactured, packaged, advertised, and
sold in a manner similar to cigarettes. Little cigars enjoy several legal
advantages over cigarettes: They have access to television advertising;
they are taxed by the Federal Government and by most States, at much
lower rates than cigarettes, resulting in a significant price advantage; -

222
and they do not carry the warning label required on cigarette pack-
ages and in cigarette advertising. A market appears to be developing
for these 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 potential public health impact of
these little cigars. An adequate epidemiological evaluation of the ef-
fect of little cigar smoking on health could take 10 or 15 years and is
probably an impractical consideration ; however, a review of the epide-
miological, 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 cigars contain similar com-
pounds in similar concentrations. Two exceptions are reducing sugars,
which are not found in quantity in the fermented tobaccos 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 last
puff, whereas 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 identical with
those obtained with cigarettes “tars”. In addition, the epidemiological
data suggest that depth of inhalation probably accounts for the fact
that cigarettes are so much more harmful than cigars and pipes in con-
tributing to the development of lung cancer, coronary heart disease,
and nonneoplastic respiratory disease. For such diseases as 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 pres-
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 whereby the
smoke is rarely inhaled would probably result in lower rates of those
pulmonary and cardiovascular diseases than would be found among
cigarette smokers.

Only a limited analysis is available comparing the chemical com-
pounds found in little cigars, cigarettes, and large cigars. The FTC
analyzed the tar and nicotine content of all the little cigars (84) and
cigarettes (97) currently available on the market, Little cigars have

223
generally a higher “tar” and nicotine level than cigarettes, although
considerable overlap results in some little cigar brands having “tar”
and nicotine levels comparable to those of some brands of cigarettes
(figs. 4 and 5). Hoffmann and Wynder (44) recently compared three
brands of little cigars with an unfiltered cigarette, a filtered cigarette,
and a large cigar. They measured a number of smoke constituents, in-
eluding: “tar,” nicotine, carbon monoxide, carbon dioxide, reducing
sugars, hydrogen cyanide, acetaldehyde, acrolein, pyridines, phenols,
benz(a)anthracene, and benzo(a)pyrene (table 32). Cigarette A was
the Kentucky reference cigarette, cigarette B was a popular brand of
filter cigarette. Cigar A was an 85 mm, little cigar, cigar B was an
85 mm. little cigar, cigar C was a 95 mm. small cigar, and cigar D was
a 112 mm. popular brand of medium sized cigar.

The smoke pH was analyzed puff by puff (table 39). Cigarette
smoke was found to be acidic (pH less than 7) for the entire cigarette.
The smoke from little cigars became alkaline only in the last puff or
two, whereas 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 (15), using the same techniques de-
scribed above. examined the effect of 60 leaf constituents on smoke pH.
For several varieties of cigarette tobacco, they found a high correlation
between the total aklaloid and nitrogen content and smoke pH. Stalk
position also affected smoke pH. Tobacco leaves near the top of the
plant, which 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 what extent. these factors influence the pH of the smoke
of tobaccos commonly used in cigars or how these kinds of pH changes
influence the inhalability of tobacco smoke.

The inhalation of smoke, however, appears to be the most important
factor determining the impact a cigar will have on overall health.
Those physical and chemical characteristics of a tobacco product
which most influence inhalation of tobacco smoke have not been
accurately determined. Nevertheless, it appears likely that the smoke
of some brands of cigars may be compatible with 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
levels found in cigarettes, and (>) the pH of the 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.

224
It is reasonable to conclude that smoking little cigars may result in
health effects similar to those associated with smoking cigarettes if
little cigars are smoked in amounts and with patterns of inhalation
similar to those used by cigarette smokers, for the reasons cited above,
and these additional reasons: (a) In those little cigars for which pre-
liminary data are available, the concentrations of carbon monoxide,
hydrogen cyanide, acetaldehyde, acrolein, pyridine, phenol, and poly-
eyclic hydrocarbon levels are comparable to those found in cigarettes:
(8) cigarette smokers who switch to cigars appear to be more likely
to inhale cigar smoke than cigar smokers who have always smoked
cigars (74); and (c) cigarette smokers who switch to little cigars may
be 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 distribution of 130 brands of cigarettes and 25 brands of little cigars by

 

 

 

 

 

 

 

 

 

 

 

 

“tar’’ content.
50}
4s [Cigarettes VY / /]
Little Cigars |
wo} g
35} i)
° 30t iY)
& )
G a
=. 2 )
8 o 9 25 P i)
e * )
20} i)
Z
15} 4
4
10} Z
‘| Y |
of A LIM te. ||
Mg. “‘tar’’ 0 0 0 16.0 8.0 32.0 32.0 0 8.0 4.0
Cigarettes 0-4 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49
Little Cigars 3.1 3.1 10.0 46.2 23.1 10.0 39 08 0 0

 

SOURCE: U.S. Department of Health, Education, and Welfare (97) and Federal Trade Commission (34),

225