Archives of Environmental Health: An International Journal
ISSN: 0003-9896 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/vzeh20
The Role of Carbon Monoxide in Cigarette Smoking Jack C. Robinson PhD & William F. Forbes PhD, DSc To cite this article: Jack C. Robinson PhD & William F. Forbes PhD, DSc (1975) The Role of Carbon Monoxide in Cigarette Smoking, Archives of Environmental Health: An International Journal, 30:9, 425-434, DOI: 10.1080/00039896.1975.10666743 To link to this article: http://dx.doi.org/10.1080/00039896.1975.10666743
Published online: 02 May 2013.
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Date: 09 June 2016, At: 10:31
Scientific Communications
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The Role of Carbon Monoxide • In Cigarette Smoking 1. Carbon Monoxide Yield From Cigarettes Jack C. Robinson, PhD, William F. Forbes, PhD, DSc
• The carbon monoxide deliveries of 20 major Canadian brands of cigarettes, determined by gas chromatography and using standard smoking conditions, were estimated and found to vary by a factor of about two. The CO yields were found to increase with puff volume and tobacco mOisture, decrease with increased paper porosity, but remain essentially constant with puff duration. The data suggest that reduced CO deliveries can be achieved by increasing the cigarette paper porosity. Combustion temperature presumably also influences CO deliveries, but the relative role ascribed to dilution and combustion is not clear. It may be concluded that smokers can lower their CO exposure by reducing their puff volume, smoking cigarettes manufactured from high porosity paper, by taking fewer puffs, and decreasing their tendency to inhale. Since CO and tar deliveries are correlated, these measures would also tend to decrease a smoker's exposure to tar. (Arch Environ Health 30:425-434, 1975)
Submitted for publication Nov 27, 1974; accepted Dec 6. From the Department of Statistics, Faculty of Mathematics, the University of Waterloo, Waterloo, Ontario, Canada (Drs. Robinson and Forbes). Reprint requests to the Faculty of Mathematics, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 (Dr. Forbes).
Arch Environ Health-Vol 30, Sept 1975
N
umerous epidemiological studies have implicated cigarette smoking as a major risk factor in coronary heart disease'-- in conjunction with other risk factors such as high serum cholesterol, low physical activity, and high blood pressure. 9 - 17 Cigarette smoking has been reported as the most important source of CO exposure that affects almost one half of the adult American population,'8 and many studies have noted the relatively high CORb level in the blood of smokers, usually greater than 2%,'9-27 although CORb levels in smokers may be only a measure of depth of inhalation!8 Moreover, animal studies implicate CO as a cause of arteriosclerosis. 29 -32 Attempts to relate CORb levels to CO concentrations in tobacco smoke have not been quantitative;3.33 partly because of lack of data on the CO delivery of manufactured cigarettes (but see references 34 to 37). The present paper reports the CO delivery of typical Canadian cigarettes smoked under varying conditions, and a comparison with the corresponding deliveries of tar and nicotine, which have been reported previously.38 The comparison of tar, nicotine, and CO deliveries for different cigarettes is of interest in designing a less Carbon Monoxide-Robinson & Forbes
425
_Fij}~~C?tt' Ascarite ' " Cambridge Filter
Downloaded by [University of Arizona] at 10:31 09 June 2016
a
Gas Sampling Valve Air Collection Bag (Drager) Molecular
Correction for Dead Space
Sieve
The system, illustrated in Fig l,a, contains "dead space" in which mixing of successive puffs occurs. This "dead space" consists of the volume between the cigarette tip and the inlet to the gas chromatograph column, which interferes with the direct determination of the CO concentration in individual puffs. However, it is possible to correct the observed CO concentrations, allowing for dead space, and such a correction has been applied to the data plotted in Fig 2 and 3. The relevant equation is
Column
Fig i.-Collection and analysis of carbon monoxide: a, puff by puff method and b, average puff method.
hazardous cigarette for the following reason. If these three constituents are all positively and closely correlated, the reduction of tar should normally also lead to reduced nicotine and CO deliveries. At present there is a tendency for manufactured cigarettes to deliver less tar and nicotine than previously (see Schmahl'9 and unpublished information from this laboratory); if the above relation holds, this tendency would have the additional advantage of reduced CO deliveries. However, if there is little correlation between tar and nicotine deliveries on the one hand, and CO deliveries on the other hand, this would then suggest that it may be possible to manufacture a cigarette that will deliver almost any amount of CO, tar, and nicotine within certain limits. This observation is of potential interest since it may permit the design of a cigarette that would be less hazard426
(Ascarite) (3 gm) and into a syringe as shown in Fig l,a. Ascarite was necessary to remove carbon dioxide that interfered with the rapid determination of CO" (see later discussion). The smoke was then directed through a solenoid valve into a short 3-mm in diameter tube and onto the molecular sieve column of a gas chromatograph (Beckman GC-45). Each puff, including the puff used to light the cigarette, was injected at the rate of one per minute. The cigarettes were smoked to the puff nearest the 30-mm butt length mark; then a final puff was taken with the cigarette removed from the holder (see section "Correction for Dead Space"). These procedures, apart from the frequency of injection, are similar to those reported previously,-" except that the column was maint.ained at 130 C wit.h a helium flow rate of 100 ml!min. The signal detected by a thermal conductivity cell was recorded and integrated. Six cigarettes, including a control cigarette, were smoked before column reconditioning was required when the methane and CO peaks failed to separate.
ous. It is unlikely that the tobacco smoke constituents that lead to habituation, carcinogenic activity, and increased incidence of heart disease represent identical chemical substances. METHODS Cigarettes were purchased on the open market by Canadian Food and Drug Directorate Field Inspectors. All cigarettes were conditioned at 60% relative humidity and 22 C for a minimum of 48 hours prior to smoking. Cigarettes were smoked under standard smoking conditions 40 on a single port smoking machine (Phipps and Bird Model 900c 300). The cigarettes were smoked in randomized order, with frequent gas chromatograph calibration carried out using a known CO primary standard (5.03% CO, Matheson).
Puff by Puff Method The smoke was passed through a Cambridge filter and then drawn over asbestos coated with sodium hydroxide
Arch Environ Health-Vol 30, Sept 1975
0 1+1 = 0'1+1 -
.
[ + o'r] 1
C'f 0'£-1
[
-o~'f ]
X
'
C'f-l
l=O, ... ,f-1... (1), CO concentration in puff i; C'i = observed CO concentration in puff i; Vp = volume of puff; V D = volume of dead space; and (Vp+VD ) volume in which mixing occurs. Details concerning the derivation of equation (1) are available on request.
where Ci
= actual
=
Puff by Puff Method The smoke from all puffs, collected during the smoking of a cigarette, was passed through the solenoid into a 1-Iiter air-collection bag (Fig 1,b). Each puff, including the first but excluding the clearing puff, was collected in the bag.
Carbon Monoxide-Robinson & Forbes
b
a
E
.......
::3
II.
... !l'l
II.
oOJ
0
OJ
Downloaded by [University of Arizona] at 10:31 09 June 2016
1.5
--rf
-~k5f
------ rp
------1I:5f'"
Fig 2.-Delivery of CO per puff as a function of puff number for 20 brands of Canadian cigarettes. CO per puff vs puff number for (a) regular size cigarettes and (b) king size cigarettes. Each line represents the best fit as judged by least squares regression (residual variations suggest that the relationship is essentially linear). The first puff was ignored in each case (see Williams and Belk"). Individual points are not shown. The rf = regular-size filters; rp, regular size plain; ksf, king size filler; and ksfm, king size filter menthol.
(Including the clearing puff would reduce the average CO concentration since the clearing puff consists of both dead space CO and air. No correction has been made for this dead space CO, but it is estimated that this omission would not affect the results by more than 3%.) After the final puff, the bag was closed, removed from the smoking machine, and a sample of its contents was injected onto the column through the gas sampling valve. The determination of CO in this sample, when calibrated against the primary standard, provided an estimate of the average CO per puff, and total CO was estimated by multiplication with the number of puffs taken (Table 1). Ascarite, a CO 2 absorbent, was omitted in the determinations involving samples collected during January 1972. It was reintroduced, however, for the November 1972 samples, when it was noted that the presence of Ascarite, although leading to higher CO values (Table 1), eliminated the partial interference of CO 2 peaks with the CO determination. The higher CO readings in the presence of Ascarite could not be explained although they were not due to the space occupied by Ascarite, since other inert particles did not Arch Environ Health-Vol 30, Sept 1975
Fig 3.-Slope of the regression line (CO per puff vs puff number; see Fig 2) vs cigarette paper porosity.
.210 I-
.......
.15
it
-
d-u
e
E w
.10
~
-
@
~
A.
9 !II
;e:
0
• • • •
.05 i-
, I
,
.,
2
3
•
reg •
..,king
,
,
,
,
,
\
7
POROSITY (ml/sec)
Carbon Monoxide-Robinson & Forbes
427
E
t .....
a
> :::;
20
Q
10
..... 0 u
0
en
t .....
ii
10
> :;
20
Q
30
.....
c
d
r-,-
~ CO')
c?
E
b
-- -0-
.0
'lit
.0
.0 CO')
r--
..q
I..-
-
GO
N
iii
N
l..-
iii
-
r,..-
-
- - "-
00
0:
1ft
r--
r--
-- - 0:
1ft
N
N
ar::
-
,.....
~
~
o:r
~
00
N
N
......
....
'--
2
3
0:
GO
«'!
.0 N
1ft N
CO')
N
GO
1ft
......
......
10 20
30
'--
c( ....
20
... c( ~
35 50
PUFF VOLUME
Z
..... ....
1
PUFF DURATION
ml
dry std. moist
•
PAPER POROSITY
sec
TOBACCO MOl STURE CONTENT
sec
0
Downloaded by [University of Arizona] at 10:31 09 June 2016
1:1.
Fig 4.-Mean Responses for total potential tar and paper porosity; and d, means for tobacco moisture. example, the means for puff volume are summed for inside the bars in this and the subsequent figures subsequent two figures, see Table 2.
CO deliveries. a, means for puff volume; b, means for puff duration; c, means for Each set of meansis summed for all different levels of the other measures; for all different levels of puff duration, paper porosity, and tobacco moisture. Figure represents the mean of 54 observations. For definitions used in this and the
produce this effect. This phenomenon is being investigated further.
Other Determinations Tar and nicotine contents of mainstream smoke were determined using standard methods," with tar reported on a wet weight basis. Filter efficiencies, "e," for nicotine were determined using the Coresta Standard method." The "potential tar delivery (A + B)" was obtained by adding the amount of tar (A) retained on the Cambridge filter, through which the smoke is passed (ie, tar delivery), to the amount of tar (B) estimated to be trapped in the cigarette filter. It was shown elsewhere" that:
B.;:OA[_e]
l-e (2) where A = tar delivery (mg) ; B tar estimated to be trapped in cigarette filter, using equation (2); and e = filter efficiency for nicotine. (The use of the filter efficiency for nicotine, in equation (2), assumes that the selectivity of the filter material for nicotine is the same as that for tar, since the filter efficiency for tar was not determined. Also it may be noted that filter efficiencies are affected by puff measures, such as puff volume and puff duration, and no allowance has been made for this.)
=
Paper Porosity In order to investigate the influence of 428
Arch Environ Health-Vol 30, Sept 1975
Table 1.-Total Carbon Monoxide Deliveries (in ml) of Some Major Canadian Cigarette Brands·
,
Puff by Puff Methodt (With Ascarite) A
Average Puff Methodt
,
,
,
Without Ascarite
,
f
No. of Brand
Regular size Belvedere Craven A Du Maurier Export, plain Export A Mark 10 Matinee Peter Jackson Players, plain Players, filter King size Belvedere #7 Cameo Craven A Craven M Du Maurier Export A Matinee Peter Jackson Rothmans
, ,
,
With Ascarite
,
No. of
,
No. of
CO
Puffs
CO
Puffs
CO
Puffs
13.3 ± 1.1t 12.8± 1.0 17.4 ± 0.9 15.3 ±0.8 14.2± 1.2 16.7± 1.1 13.7± 1.7 17.4±1.1 18.1 ± 1.6 17.4±1.1
7 7 8 8 8 8 7 8 8 8
11.7±0.n 11.5±0.8 16.3 ± 1.2 13.3 ± 1.3 12.5 ± 0.3 16.5 ± 0.6 12.2±0.7 16.7 ± 0.8 16.5:± 0.8 16.2 ± 0.7
7 7 8 8 8 8 6 8 8 8
15.1 ± 0.9t 13.6:± 1.2 16.5 ± 1.0 14.3± 1.4 15.5±1.6 18.0± 1.2 13.9± 1.5' 18.2± 1.8 18.0± 1.1 18.0± 1.2
7 7 8 8 8 8 7 8 8 8
17.7 ± 1.6 21.1 ± 1.9 22.7± 1.4 15.9·± 1.1 15.8±1.1 22.6± 1.3 17.8± 1.0 15.4± 1.7 21.3 ± 1.4 19.4+2.4
10 11 10 10 10 10 10 9 10 11
16.0 ± 1.2 19.8± 1.0 20.8 ± 1.0 14.4 ± 1.1 15.1 ±0.7 19.9±0.6 16.8 ± 0.8 16.6 ± 2.0 19.8 ±0.8 17.9± 1.0
10 10 10 9 9 10 10 9 10 10
17.4± 1.4 19.9± 1.0 23.0 ± 1.4 16.9± 1.0 15.9± 1.1 21.7± 0.8 19.4 ±·2.8 15.8±1.6 21.9± 1.1 20.3 ± 1.5
9 10 9 9 10 10 10 8 10 10
• Volumes at constant temperature and pressure (18 C, 1 atmosphere).
t For experimental procedures used, see text.
t 95% confidence limits of the. mean.
Carbon Monoxide-Robinson & Forbes
Downloaded by [University of Arizona] at 10:31 09 June 2016
porosity on CO and potential tar delivery, cigarettes were obtained that were manufactured from citrate paper of 10, 20, and 30 seconds porosities. All cigarettes were identical with respect to tobacco blend and filter. To provide a range of conditions over which the effect of paper porosity could be investigated, puff volume, puff duration, and tobacco moisture content were varied (Table 2 and Fig 4 to 6), and each of these four factors was assigned three levels (see footnotes to Table 2). (The puff profile of a smoker is probably as important as puff volume and duration, and exposure might also be investigated using various puff profiles in addition to that of the smoking machine as described in this report.) The experiment was conducted as a 34 design, and the entire experiment was duplicated. A second experiment extended the range of puff duration from 0.5 to 4.5 seconds, for all porosities at fixed puff volume (35 ml), and standard tobacco moisture content." This experiment was also duplicated. RESULTS AND COMMENT Total Carbon Monoxide Deliveries
The CO deliveries obtained for 20 different brands of Canadian cigarettes are shown in Table 1. Regular size cigarettes range in CO delivery from 11.5 to 18.2 ml, while king size cigarettes range from 14.4 to 23.0 ml. Figure 7,a illustrates the relationship between tar and CO deliveries. The results show that CO deliveries vary by a factor of about two for different brands, and that the correlation between tar deliveries and CO deliveries is significant (ex
ISSN: 0003-9896 (Print) (Online) Journal homepage: http://www.tandfonline.com/loi/vzeh20
The Role of Carbon Monoxide in Cigarette Smoking Jack C. Robinson PhD & William F. Forbes PhD, DSc To cite this article: Jack C. Robinson PhD & William F. Forbes PhD, DSc (1975) The Role of Carbon Monoxide in Cigarette Smoking, Archives of Environmental Health: An International Journal, 30:9, 425-434, DOI: 10.1080/00039896.1975.10666743 To link to this article: http://dx.doi.org/10.1080/00039896.1975.10666743
Published online: 02 May 2013.
Submit your article to this journal
Article views: 5
View related articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=vzeh20 Download by: [University of Arizona]
Date: 09 June 2016, At: 10:31
Scientific Communications
Downloaded by [University of Arizona] at 10:31 09 June 2016
The Role of Carbon Monoxide • In Cigarette Smoking 1. Carbon Monoxide Yield From Cigarettes Jack C. Robinson, PhD, William F. Forbes, PhD, DSc
• The carbon monoxide deliveries of 20 major Canadian brands of cigarettes, determined by gas chromatography and using standard smoking conditions, were estimated and found to vary by a factor of about two. The CO yields were found to increase with puff volume and tobacco mOisture, decrease with increased paper porosity, but remain essentially constant with puff duration. The data suggest that reduced CO deliveries can be achieved by increasing the cigarette paper porosity. Combustion temperature presumably also influences CO deliveries, but the relative role ascribed to dilution and combustion is not clear. It may be concluded that smokers can lower their CO exposure by reducing their puff volume, smoking cigarettes manufactured from high porosity paper, by taking fewer puffs, and decreasing their tendency to inhale. Since CO and tar deliveries are correlated, these measures would also tend to decrease a smoker's exposure to tar. (Arch Environ Health 30:425-434, 1975)
Submitted for publication Nov 27, 1974; accepted Dec 6. From the Department of Statistics, Faculty of Mathematics, the University of Waterloo, Waterloo, Ontario, Canada (Drs. Robinson and Forbes). Reprint requests to the Faculty of Mathematics, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1 (Dr. Forbes).
Arch Environ Health-Vol 30, Sept 1975
N
umerous epidemiological studies have implicated cigarette smoking as a major risk factor in coronary heart disease'-- in conjunction with other risk factors such as high serum cholesterol, low physical activity, and high blood pressure. 9 - 17 Cigarette smoking has been reported as the most important source of CO exposure that affects almost one half of the adult American population,'8 and many studies have noted the relatively high CORb level in the blood of smokers, usually greater than 2%,'9-27 although CORb levels in smokers may be only a measure of depth of inhalation!8 Moreover, animal studies implicate CO as a cause of arteriosclerosis. 29 -32 Attempts to relate CORb levels to CO concentrations in tobacco smoke have not been quantitative;3.33 partly because of lack of data on the CO delivery of manufactured cigarettes (but see references 34 to 37). The present paper reports the CO delivery of typical Canadian cigarettes smoked under varying conditions, and a comparison with the corresponding deliveries of tar and nicotine, which have been reported previously.38 The comparison of tar, nicotine, and CO deliveries for different cigarettes is of interest in designing a less Carbon Monoxide-Robinson & Forbes
425
_Fij}~~C?tt' Ascarite ' " Cambridge Filter
Downloaded by [University of Arizona] at 10:31 09 June 2016
a
Gas Sampling Valve Air Collection Bag (Drager) Molecular
Correction for Dead Space
Sieve
The system, illustrated in Fig l,a, contains "dead space" in which mixing of successive puffs occurs. This "dead space" consists of the volume between the cigarette tip and the inlet to the gas chromatograph column, which interferes with the direct determination of the CO concentration in individual puffs. However, it is possible to correct the observed CO concentrations, allowing for dead space, and such a correction has been applied to the data plotted in Fig 2 and 3. The relevant equation is
Column
Fig i.-Collection and analysis of carbon monoxide: a, puff by puff method and b, average puff method.
hazardous cigarette for the following reason. If these three constituents are all positively and closely correlated, the reduction of tar should normally also lead to reduced nicotine and CO deliveries. At present there is a tendency for manufactured cigarettes to deliver less tar and nicotine than previously (see Schmahl'9 and unpublished information from this laboratory); if the above relation holds, this tendency would have the additional advantage of reduced CO deliveries. However, if there is little correlation between tar and nicotine deliveries on the one hand, and CO deliveries on the other hand, this would then suggest that it may be possible to manufacture a cigarette that will deliver almost any amount of CO, tar, and nicotine within certain limits. This observation is of potential interest since it may permit the design of a cigarette that would be less hazard426
(Ascarite) (3 gm) and into a syringe as shown in Fig l,a. Ascarite was necessary to remove carbon dioxide that interfered with the rapid determination of CO" (see later discussion). The smoke was then directed through a solenoid valve into a short 3-mm in diameter tube and onto the molecular sieve column of a gas chromatograph (Beckman GC-45). Each puff, including the puff used to light the cigarette, was injected at the rate of one per minute. The cigarettes were smoked to the puff nearest the 30-mm butt length mark; then a final puff was taken with the cigarette removed from the holder (see section "Correction for Dead Space"). These procedures, apart from the frequency of injection, are similar to those reported previously,-" except that the column was maint.ained at 130 C wit.h a helium flow rate of 100 ml!min. The signal detected by a thermal conductivity cell was recorded and integrated. Six cigarettes, including a control cigarette, were smoked before column reconditioning was required when the methane and CO peaks failed to separate.
ous. It is unlikely that the tobacco smoke constituents that lead to habituation, carcinogenic activity, and increased incidence of heart disease represent identical chemical substances. METHODS Cigarettes were purchased on the open market by Canadian Food and Drug Directorate Field Inspectors. All cigarettes were conditioned at 60% relative humidity and 22 C for a minimum of 48 hours prior to smoking. Cigarettes were smoked under standard smoking conditions 40 on a single port smoking machine (Phipps and Bird Model 900c 300). The cigarettes were smoked in randomized order, with frequent gas chromatograph calibration carried out using a known CO primary standard (5.03% CO, Matheson).
Puff by Puff Method The smoke was passed through a Cambridge filter and then drawn over asbestos coated with sodium hydroxide
Arch Environ Health-Vol 30, Sept 1975
0 1+1 = 0'1+1 -
.
[ + o'r] 1
C'f 0'£-1
[
-o~'f ]
X
'
C'f-l
l=O, ... ,f-1... (1), CO concentration in puff i; C'i = observed CO concentration in puff i; Vp = volume of puff; V D = volume of dead space; and (Vp+VD ) volume in which mixing occurs. Details concerning the derivation of equation (1) are available on request.
where Ci
= actual
=
Puff by Puff Method The smoke from all puffs, collected during the smoking of a cigarette, was passed through the solenoid into a 1-Iiter air-collection bag (Fig 1,b). Each puff, including the first but excluding the clearing puff, was collected in the bag.
Carbon Monoxide-Robinson & Forbes
b
a
E
.......
::3
II.
... !l'l
II.
oOJ
0
OJ
Downloaded by [University of Arizona] at 10:31 09 June 2016
1.5
--rf
-~k5f
------ rp
------1I:5f'"
Fig 2.-Delivery of CO per puff as a function of puff number for 20 brands of Canadian cigarettes. CO per puff vs puff number for (a) regular size cigarettes and (b) king size cigarettes. Each line represents the best fit as judged by least squares regression (residual variations suggest that the relationship is essentially linear). The first puff was ignored in each case (see Williams and Belk"). Individual points are not shown. The rf = regular-size filters; rp, regular size plain; ksf, king size filler; and ksfm, king size filter menthol.
(Including the clearing puff would reduce the average CO concentration since the clearing puff consists of both dead space CO and air. No correction has been made for this dead space CO, but it is estimated that this omission would not affect the results by more than 3%.) After the final puff, the bag was closed, removed from the smoking machine, and a sample of its contents was injected onto the column through the gas sampling valve. The determination of CO in this sample, when calibrated against the primary standard, provided an estimate of the average CO per puff, and total CO was estimated by multiplication with the number of puffs taken (Table 1). Ascarite, a CO 2 absorbent, was omitted in the determinations involving samples collected during January 1972. It was reintroduced, however, for the November 1972 samples, when it was noted that the presence of Ascarite, although leading to higher CO values (Table 1), eliminated the partial interference of CO 2 peaks with the CO determination. The higher CO readings in the presence of Ascarite could not be explained although they were not due to the space occupied by Ascarite, since other inert particles did not Arch Environ Health-Vol 30, Sept 1975
Fig 3.-Slope of the regression line (CO per puff vs puff number; see Fig 2) vs cigarette paper porosity.
.210 I-
.......
.15
it
-
d-u
e
E w
.10
~
-
@
~
A.
9 !II
;e:
0
• • • •
.05 i-
, I
,
.,
2
3
•
reg •
..,king
,
,
,
,
,
\
7
POROSITY (ml/sec)
Carbon Monoxide-Robinson & Forbes
427
E
t .....
a
> :::;
20
Q
10
..... 0 u
0
en
t .....
ii
10
> :;
20
Q
30
.....
c
d
r-,-
~ CO')
c?
E
b
-- -0-
.0
'lit
.0
.0 CO')
r--
..q
I..-
-
GO
N
iii
N
l..-
iii
-
r,..-
-
- - "-
00
0:
1ft
r--
r--
-- - 0:
1ft
N
N
ar::
-
,.....
~
~
o:r
~
00
N
N
......
....
'--
2
3
0:
GO
«'!
.0 N
1ft N
CO')
N
GO
1ft
......
......
10 20
30
'--
c( ....
20
... c( ~
35 50
PUFF VOLUME
Z
..... ....
1
PUFF DURATION
ml
dry std. moist
•
PAPER POROSITY
sec
TOBACCO MOl STURE CONTENT
sec
0
Downloaded by [University of Arizona] at 10:31 09 June 2016
1:1.
Fig 4.-Mean Responses for total potential tar and paper porosity; and d, means for tobacco moisture. example, the means for puff volume are summed for inside the bars in this and the subsequent figures subsequent two figures, see Table 2.
CO deliveries. a, means for puff volume; b, means for puff duration; c, means for Each set of meansis summed for all different levels of the other measures; for all different levels of puff duration, paper porosity, and tobacco moisture. Figure represents the mean of 54 observations. For definitions used in this and the
produce this effect. This phenomenon is being investigated further.
Other Determinations Tar and nicotine contents of mainstream smoke were determined using standard methods," with tar reported on a wet weight basis. Filter efficiencies, "e," for nicotine were determined using the Coresta Standard method." The "potential tar delivery (A + B)" was obtained by adding the amount of tar (A) retained on the Cambridge filter, through which the smoke is passed (ie, tar delivery), to the amount of tar (B) estimated to be trapped in the cigarette filter. It was shown elsewhere" that:
B.;:OA[_e]
l-e (2) where A = tar delivery (mg) ; B tar estimated to be trapped in cigarette filter, using equation (2); and e = filter efficiency for nicotine. (The use of the filter efficiency for nicotine, in equation (2), assumes that the selectivity of the filter material for nicotine is the same as that for tar, since the filter efficiency for tar was not determined. Also it may be noted that filter efficiencies are affected by puff measures, such as puff volume and puff duration, and no allowance has been made for this.)
=
Paper Porosity In order to investigate the influence of 428
Arch Environ Health-Vol 30, Sept 1975
Table 1.-Total Carbon Monoxide Deliveries (in ml) of Some Major Canadian Cigarette Brands·
,
Puff by Puff Methodt (With Ascarite) A
Average Puff Methodt
,
,
,
Without Ascarite
,
f
No. of Brand
Regular size Belvedere Craven A Du Maurier Export, plain Export A Mark 10 Matinee Peter Jackson Players, plain Players, filter King size Belvedere #7 Cameo Craven A Craven M Du Maurier Export A Matinee Peter Jackson Rothmans
, ,
,
With Ascarite
,
No. of
,
No. of
CO
Puffs
CO
Puffs
CO
Puffs
13.3 ± 1.1t 12.8± 1.0 17.4 ± 0.9 15.3 ±0.8 14.2± 1.2 16.7± 1.1 13.7± 1.7 17.4±1.1 18.1 ± 1.6 17.4±1.1
7 7 8 8 8 8 7 8 8 8
11.7±0.n 11.5±0.8 16.3 ± 1.2 13.3 ± 1.3 12.5 ± 0.3 16.5 ± 0.6 12.2±0.7 16.7 ± 0.8 16.5:± 0.8 16.2 ± 0.7
7 7 8 8 8 8 6 8 8 8
15.1 ± 0.9t 13.6:± 1.2 16.5 ± 1.0 14.3± 1.4 15.5±1.6 18.0± 1.2 13.9± 1.5' 18.2± 1.8 18.0± 1.1 18.0± 1.2
7 7 8 8 8 8 7 8 8 8
17.7 ± 1.6 21.1 ± 1.9 22.7± 1.4 15.9·± 1.1 15.8±1.1 22.6± 1.3 17.8± 1.0 15.4± 1.7 21.3 ± 1.4 19.4+2.4
10 11 10 10 10 10 10 9 10 11
16.0 ± 1.2 19.8± 1.0 20.8 ± 1.0 14.4 ± 1.1 15.1 ±0.7 19.9±0.6 16.8 ± 0.8 16.6 ± 2.0 19.8 ±0.8 17.9± 1.0
10 10 10 9 9 10 10 9 10 10
17.4± 1.4 19.9± 1.0 23.0 ± 1.4 16.9± 1.0 15.9± 1.1 21.7± 0.8 19.4 ±·2.8 15.8±1.6 21.9± 1.1 20.3 ± 1.5
9 10 9 9 10 10 10 8 10 10
• Volumes at constant temperature and pressure (18 C, 1 atmosphere).
t For experimental procedures used, see text.
t 95% confidence limits of the. mean.
Carbon Monoxide-Robinson & Forbes
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porosity on CO and potential tar delivery, cigarettes were obtained that were manufactured from citrate paper of 10, 20, and 30 seconds porosities. All cigarettes were identical with respect to tobacco blend and filter. To provide a range of conditions over which the effect of paper porosity could be investigated, puff volume, puff duration, and tobacco moisture content were varied (Table 2 and Fig 4 to 6), and each of these four factors was assigned three levels (see footnotes to Table 2). (The puff profile of a smoker is probably as important as puff volume and duration, and exposure might also be investigated using various puff profiles in addition to that of the smoking machine as described in this report.) The experiment was conducted as a 34 design, and the entire experiment was duplicated. A second experiment extended the range of puff duration from 0.5 to 4.5 seconds, for all porosities at fixed puff volume (35 ml), and standard tobacco moisture content." This experiment was also duplicated. RESULTS AND COMMENT Total Carbon Monoxide Deliveries
The CO deliveries obtained for 20 different brands of Canadian cigarettes are shown in Table 1. Regular size cigarettes range in CO delivery from 11.5 to 18.2 ml, while king size cigarettes range from 14.4 to 23.0 ml. Figure 7,a illustrates the relationship between tar and CO deliveries. The results show that CO deliveries vary by a factor of about two for different brands, and that the correlation between tar deliveries and CO deliveries is significant (ex
