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When low tar cigarettes yield high tar: Cigarette filter ventilation hole blocking and its detection
AddictiveBehaviors, Vol. 8, pp. 67-69, Printed in the USA. All rights reserved.
0306-4603/83/010067-03%03.00/O Copyright e 1983 Pergamon Press Ltd
1983
BRIEF REPORT WHEN LOW TAR CIGARETTES YIELD HIGH TAR: CIGARETTE FILTER VENTILATION HOLE BLOCKING AND ITS DETECTION THOMAS
LOMBARDO, Jackson
CECELIA
V.A. and Univesity
JO DAVIS, DONALD
of Mississippi
Medical
M. PRUE
Centers
The majority of low tar, nicotine, and carbon monoxide cigarettes reduce mainstream smoke constituents by means of filter ventilation holes. Approximately 50% of low tar smokers, however, admit to blocking or partially blocking these holes causing increases, ranging from 60% to 300%, in toxic substances (Kozlowski, Frecker, Khouw, & Pope, 1980). Thus, detecting hole blocking would be important for both research and epidemiological studies evaluating low tar cigarettes. Kozlowski et al. (1980) recently suggested that partial, complete and no blocking of ventilation holes can be readily discriminated by distinctive stain patterns of tar deposits on cigarette butt ends. Unfortunately, their study did not empirically test this assertion. Furthermore, discriminability was predicted on the basis of machine smoked stain patterns rather than those of actual smokers. This leads to questions regarding whether individuals’ idiosyncratic smoking topographies (Moss & Prue, 1982) produce more variable and, therefore, less discriminable stain patterns than machine smoked butts. A second question raised by Kozlowski et al.‘s study involves the method of hole blocking. Kozlowski et al.‘s (1980) partially blocked cigarettes were blocked as if two opposing fingers covered 50% of the holes. However, during the course of smoking a cigarette, smokers may switch the holes they cover as they move the cigarette about. A more appropriate test method for partial blocking would, therefore, be to block holes across the circumference of the cigarette. The present study attempted to provide some initial data on: (1) how accurately raters could discriminate stain patterns of cigarettes with unblocked, partially blocked, and completely blocked ventilation holes; (2) whether discriminability differs between machine and human smoked cigarette butts; and (3) whether ratings based on the figure of stain patterns presented by Kozlowski et al. (1980) would differ in accuracy from ratings based upon actual samples of cigarette butts. METHOD
The study consisted of four phases. First, the average proportion of partial filter hole blockage was empirically determined by having 8 smokers (4 males and 4 females) hold low tar and nicotine cigarettes (Kent III filter cigarettes were used throughout the Portions of this research were funded by the Veterans Administration Medical Research Program (Program #9865-O]). The study was conducted while the first author was an intern at the Jackson Veterans Administration and University of Mississippi Medical Centers Internship Training Consortium. Tom Lombard0 is now at the Department of Psychology, University of Mississippi, University, Mississippi. Requests for reprints should be sent to Donald M. Prue, Alcohol Dependence Treatment Program, 116~1, V.A. Medical Center, Jackson, MS 39216. 61
68
THOMAS
LOMBARDO,
CECELIA
JO DAVIS
and DONALD
M. PRUE
study) between their fingertips coated with fingerprint ink. An average of 68% of ventilation holes were blocked by each sex. The second phase was the preparation of butts for rating. One set of 30 cigarettes consisting of 10 each with unblocked, partially blocked, and completely blocked ventilation holes was smoked ad lib by human subjects who regularly smoked low tar and nicotine cigarettes and denied hole blocking. A second set of 30 similarly prepared cigarettes was machine smoked according to Federal Trade Commission parameters. Sixty-six percent of ventilation holes of partially blocked cigarettes were occluded by taping closed 4 of 6 rows of holes. All ventilation holes were taped closed in completely blocked cigarettes. The third phase of the study involved preparation of a third set of butts for rating. Inspection of the human smoked butts from Phase 2 showed extremely variable stain patterns for unblocked and partially blocked cigarettes. Subsequent unobtrusive observation of smokers who prepared the original butts indicated that they were, in fact, blocking ventilation holes during their last few puffs. Therefore, a replacement set of unblocked, partially blocked and completely blocked cigarettes was smoked by subjects through a cigarette holder to eliminate the possibility of additional, albeit inadvertent, blocking. The 10 unblocked cigarettes from the first set were retained and rated for comparison purposes while the partially and completely blocked cigarettes from the set were discarded because of possible errors in determining the extent of blocking. Rating the cigarette butts was the fourth phase. Ten raters, 5 male and 5 female employees of two large medical centers, judged the stain patterns of the 70 cigarette butts for no, partial, or complete blocking using two reference criteria. First, ratings were made using the figure from the Kozlowski et al. (1980) paper. Second, ratings were repeated using three samples of machine smoked butts corresponding to each blocking condition for reference. Butts were fixed in a frame which exposed only the very tip of the stained filter to the rater. RESULTS
A series of t tests computed between male and female raters’ accuracy scores (i.e., percentage correct) for each of the 12 smoking (machine and subject), rating instruction (figure and cigarette butts), and blocking (unblocked, partially and completely blocked) condition combinations failed to reach statistical significance. Therefore, data were collapsed across sex for all subsequent analyses. The mean accuracy of correct labeling of the 10 unblocked cigarette butts which subjects smoked without a cigarette holder was only 37%, or little better than chance. In contrast, 82% of unblocked cigarettes smoked by subjects through holders were correctly labelled, and the difference in accuracy was statistically significant (t [38] = 5.20, p < .OOl). This finding underscores the need for rigid control in the preparation and standardization of cigarette butts in evaluating ventilation hole blocking detection accuracy. To evaluate the effect of smoking, rating, and blocking conditions on rating accuracy, a three factor repeated measures analysis of variance was conducted. Main effects were significant only for blocking (F [2,108] = 25.6, p < .Ol), and there were no significant interactions. Post hoc comparisons (Tukey) indicated ratings of unblocked and completely blocked cigarettes were equally accurate, and that both were more accurate than ratings of partially blocked butts (p < .Ol). The percentage of correct ratings was 79%, 52070, and 90% for unblocked, partially and completely blocked cigarettes, respectively.
Detection of hole blocking
69
To evaluate how accurately subjects could discriminate no blocking from any degree of blocking, partially and completely blocked cigarettes were combined in a second three factor repeated measures analysis of variance. As before, only blocking was significant (F [ 1,721 = 4.13, p < .05), indicating raters were more accurate in detecting blocked (9OVo)than unblocked (79%) butts. Examination of the data showed 90% of the partially blocked butts were categorized as blocked (versus unblocked). DISCUSSION
Untrained raters were able to detect completely blocked and unblocked cigarette ventilation holes with reasonable accuracy. Partially blocked cigarettes were more difficult to discriminate. Neither rating reference criteria, the Kozlowski et al. manuscript and actual butts, nor method of smoking, machine versus human subjects through filters, affected accuracy. Comparison of the accuracy of correctly categorizing any degree of blocking versus no blocking indicates the rate of false positives (incorrectly labelled unblocked cigarettes) is twice as great as the rate of false negatives (incorrectly labelling completely/partially blocked cigarettes), i.e., 21% versus 10%. The accuracy of trained raters might be much greater. The results suggest idiosyncratic smoking topography does not affect ventilation hole blocking detection accuracy. However, this conclusion is only tentative, since it was necessary to use cigarette holders to prevent smokers from blocking holes. Holders may have affected smoking patterns, perhaps reducing intersubject variability in topography parameters. An adequate test of the effect of idiosyncratic smoking topographies on detection accuracy requires the rating of cigarettes smoked without holders, preferably in the natural environment. The fact that smokers who denied covering ventilation holes were observed blocking poses a methodological obstacle to answering the topography question. It is possible that, even with trained raters, the detection of ventilation hole blocking in smokers may prove too unreliable to be useful. Finally, the proportion of smokers who block ventilation holes might be much greater than the 32% to 69% Kozlowski et al. (1980) reported from interviews. Our smokers denied blocking but were observed to block during the last few puffs when the cigarette was difficult to grasp without covering ventilation holes. Systematic observational research would reveal the prevalence of this behavior. Since toxic smoke constituents are more concentrated in the last few puffs (Gritz, 1976) cigarette ventilation holes may prove less effective than originally thought for reducing smoking health risk in smokers of low tar and nicotine cigarettes. REFERENCES Gritr, E.R. Patterns of puffing in cigarette smokers.In N.A. Krasnegor (Ed.), Self-administration ofahused substances: Methodsfor study. NIDA Research Monograph 20, DHEW, ADAMHA, 1978. Kozlowski, L.T., Frecker, R.C., Khouw, V., &Pope, M.A. The misuse of “less hazardous” cigarettes and its detection: Hole-blocking of ventilated filters. American Journal of Public Health, 1980, 70, 1202-1203. Moss, R.A., & Prue, D.M. Research on nicotine regulation. Behavior Therapy, 1982, 13, 31-46.
0306-4603/83/010067-03%03.00/O Copyright e 1983 Pergamon Press Ltd
1983
BRIEF REPORT WHEN LOW TAR CIGARETTES YIELD HIGH TAR: CIGARETTE FILTER VENTILATION HOLE BLOCKING AND ITS DETECTION THOMAS
LOMBARDO, Jackson
CECELIA
V.A. and Univesity
JO DAVIS, DONALD
of Mississippi
Medical
M. PRUE
Centers
The majority of low tar, nicotine, and carbon monoxide cigarettes reduce mainstream smoke constituents by means of filter ventilation holes. Approximately 50% of low tar smokers, however, admit to blocking or partially blocking these holes causing increases, ranging from 60% to 300%, in toxic substances (Kozlowski, Frecker, Khouw, & Pope, 1980). Thus, detecting hole blocking would be important for both research and epidemiological studies evaluating low tar cigarettes. Kozlowski et al. (1980) recently suggested that partial, complete and no blocking of ventilation holes can be readily discriminated by distinctive stain patterns of tar deposits on cigarette butt ends. Unfortunately, their study did not empirically test this assertion. Furthermore, discriminability was predicted on the basis of machine smoked stain patterns rather than those of actual smokers. This leads to questions regarding whether individuals’ idiosyncratic smoking topographies (Moss & Prue, 1982) produce more variable and, therefore, less discriminable stain patterns than machine smoked butts. A second question raised by Kozlowski et al.‘s study involves the method of hole blocking. Kozlowski et al.‘s (1980) partially blocked cigarettes were blocked as if two opposing fingers covered 50% of the holes. However, during the course of smoking a cigarette, smokers may switch the holes they cover as they move the cigarette about. A more appropriate test method for partial blocking would, therefore, be to block holes across the circumference of the cigarette. The present study attempted to provide some initial data on: (1) how accurately raters could discriminate stain patterns of cigarettes with unblocked, partially blocked, and completely blocked ventilation holes; (2) whether discriminability differs between machine and human smoked cigarette butts; and (3) whether ratings based on the figure of stain patterns presented by Kozlowski et al. (1980) would differ in accuracy from ratings based upon actual samples of cigarette butts. METHOD
The study consisted of four phases. First, the average proportion of partial filter hole blockage was empirically determined by having 8 smokers (4 males and 4 females) hold low tar and nicotine cigarettes (Kent III filter cigarettes were used throughout the Portions of this research were funded by the Veterans Administration Medical Research Program (Program #9865-O]). The study was conducted while the first author was an intern at the Jackson Veterans Administration and University of Mississippi Medical Centers Internship Training Consortium. Tom Lombard0 is now at the Department of Psychology, University of Mississippi, University, Mississippi. Requests for reprints should be sent to Donald M. Prue, Alcohol Dependence Treatment Program, 116~1, V.A. Medical Center, Jackson, MS 39216. 61
68
THOMAS
LOMBARDO,
CECELIA
JO DAVIS
and DONALD
M. PRUE
study) between their fingertips coated with fingerprint ink. An average of 68% of ventilation holes were blocked by each sex. The second phase was the preparation of butts for rating. One set of 30 cigarettes consisting of 10 each with unblocked, partially blocked, and completely blocked ventilation holes was smoked ad lib by human subjects who regularly smoked low tar and nicotine cigarettes and denied hole blocking. A second set of 30 similarly prepared cigarettes was machine smoked according to Federal Trade Commission parameters. Sixty-six percent of ventilation holes of partially blocked cigarettes were occluded by taping closed 4 of 6 rows of holes. All ventilation holes were taped closed in completely blocked cigarettes. The third phase of the study involved preparation of a third set of butts for rating. Inspection of the human smoked butts from Phase 2 showed extremely variable stain patterns for unblocked and partially blocked cigarettes. Subsequent unobtrusive observation of smokers who prepared the original butts indicated that they were, in fact, blocking ventilation holes during their last few puffs. Therefore, a replacement set of unblocked, partially blocked and completely blocked cigarettes was smoked by subjects through a cigarette holder to eliminate the possibility of additional, albeit inadvertent, blocking. The 10 unblocked cigarettes from the first set were retained and rated for comparison purposes while the partially and completely blocked cigarettes from the set were discarded because of possible errors in determining the extent of blocking. Rating the cigarette butts was the fourth phase. Ten raters, 5 male and 5 female employees of two large medical centers, judged the stain patterns of the 70 cigarette butts for no, partial, or complete blocking using two reference criteria. First, ratings were made using the figure from the Kozlowski et al. (1980) paper. Second, ratings were repeated using three samples of machine smoked butts corresponding to each blocking condition for reference. Butts were fixed in a frame which exposed only the very tip of the stained filter to the rater. RESULTS
A series of t tests computed between male and female raters’ accuracy scores (i.e., percentage correct) for each of the 12 smoking (machine and subject), rating instruction (figure and cigarette butts), and blocking (unblocked, partially and completely blocked) condition combinations failed to reach statistical significance. Therefore, data were collapsed across sex for all subsequent analyses. The mean accuracy of correct labeling of the 10 unblocked cigarette butts which subjects smoked without a cigarette holder was only 37%, or little better than chance. In contrast, 82% of unblocked cigarettes smoked by subjects through holders were correctly labelled, and the difference in accuracy was statistically significant (t [38] = 5.20, p < .OOl). This finding underscores the need for rigid control in the preparation and standardization of cigarette butts in evaluating ventilation hole blocking detection accuracy. To evaluate the effect of smoking, rating, and blocking conditions on rating accuracy, a three factor repeated measures analysis of variance was conducted. Main effects were significant only for blocking (F [2,108] = 25.6, p < .Ol), and there were no significant interactions. Post hoc comparisons (Tukey) indicated ratings of unblocked and completely blocked cigarettes were equally accurate, and that both were more accurate than ratings of partially blocked butts (p < .Ol). The percentage of correct ratings was 79%, 52070, and 90% for unblocked, partially and completely blocked cigarettes, respectively.
Detection of hole blocking
69
To evaluate how accurately subjects could discriminate no blocking from any degree of blocking, partially and completely blocked cigarettes were combined in a second three factor repeated measures analysis of variance. As before, only blocking was significant (F [ 1,721 = 4.13, p < .05), indicating raters were more accurate in detecting blocked (9OVo)than unblocked (79%) butts. Examination of the data showed 90% of the partially blocked butts were categorized as blocked (versus unblocked). DISCUSSION
Untrained raters were able to detect completely blocked and unblocked cigarette ventilation holes with reasonable accuracy. Partially blocked cigarettes were more difficult to discriminate. Neither rating reference criteria, the Kozlowski et al. manuscript and actual butts, nor method of smoking, machine versus human subjects through filters, affected accuracy. Comparison of the accuracy of correctly categorizing any degree of blocking versus no blocking indicates the rate of false positives (incorrectly labelled unblocked cigarettes) is twice as great as the rate of false negatives (incorrectly labelling completely/partially blocked cigarettes), i.e., 21% versus 10%. The accuracy of trained raters might be much greater. The results suggest idiosyncratic smoking topography does not affect ventilation hole blocking detection accuracy. However, this conclusion is only tentative, since it was necessary to use cigarette holders to prevent smokers from blocking holes. Holders may have affected smoking patterns, perhaps reducing intersubject variability in topography parameters. An adequate test of the effect of idiosyncratic smoking topographies on detection accuracy requires the rating of cigarettes smoked without holders, preferably in the natural environment. The fact that smokers who denied covering ventilation holes were observed blocking poses a methodological obstacle to answering the topography question. It is possible that, even with trained raters, the detection of ventilation hole blocking in smokers may prove too unreliable to be useful. Finally, the proportion of smokers who block ventilation holes might be much greater than the 32% to 69% Kozlowski et al. (1980) reported from interviews. Our smokers denied blocking but were observed to block during the last few puffs when the cigarette was difficult to grasp without covering ventilation holes. Systematic observational research would reveal the prevalence of this behavior. Since toxic smoke constituents are more concentrated in the last few puffs (Gritz, 1976) cigarette ventilation holes may prove less effective than originally thought for reducing smoking health risk in smokers of low tar and nicotine cigarettes. REFERENCES Gritr, E.R. Patterns of puffing in cigarette smokers.In N.A. Krasnegor (Ed.), Self-administration ofahused substances: Methodsfor study. NIDA Research Monograph 20, DHEW, ADAMHA, 1978. Kozlowski, L.T., Frecker, R.C., Khouw, V., &Pope, M.A. The misuse of “less hazardous” cigarettes and its detection: Hole-blocking of ventilated filters. American Journal of Public Health, 1980, 70, 1202-1203. Moss, R.A., & Prue, D.M. Research on nicotine regulation. Behavior Therapy, 1982, 13, 31-46.