Smoking and Tobacco Control Monograph No. 7 
their normal smoking rates. All eight smokers compensated to some degree. 
Despite being presented with twice the usual number of cigarettes, the 
smokers titrated their nicotine intake down, largely by changing their number 
of puffs, puff volume, and puff duration per cigarette. Gritz and coworkers 
disputed the view that some smokers may be compensators and others may 
be noncompensators, arguing that these two groups of smokers represent the 
opposite ends of a continuum. 
Henningfield and Griffiths (1980) studied the effect of tobacco product 
concentration on puffing rate and total number of puffs. Tobacco 
concentration levels were set at 100, 50, 25, and 10 percent by means of 
ventilated holders (identified in Figures 5 and 6 as holders 0, 1, 2, and 4). 
As shown, puffs at holder 4 were about double those of holder 0. In addition, 
there were substantial increases in puff rate. 
Compensation via alterations in puffing patterns does not explain all 
observed changes, however. In their investigation of puffing and inhalation 
patterns and yields. Nil and colleagues (1986) found that changes in puff 
volume account for only about one-fifth of the difference in smoke yields; 
no significant changes were found in inhalation patterns. On the other hand, 
with lower yield cigarettes, there was nearly complete compensation based 
on alveolar CO uptake, and the degree of increased heart rate was viewed 
as a nearly complete compensation for nicotine intake. 
McBride and colleagues (1984) measured changes in smoking behavior 
and ventilation when subjects smoked cigarettes of varying nicotine yields. 
Nine smokers were studied, and the test order was randomized. Puff volume 
was noted to increase significantly during the smoking of low-nicotine 
cigarettes. In a study of 170 male smokers and 170 age-matched male 
nonsmokers. Bridges and colleagues (1986) observed that total puff volume 
was significantly greater for smokers of cigarettes lower in nicotine yields. 
As shown in Figures 7 and 8, total puff volume was significantly correlated 
with nicotine yield and plasma cotinine. 
Researchers have observed that smokers can substantially alter tar, 
nicotine, and CO delivery of cigarettes by blocking the ventilation holes in 
the filters. In a two-part study of smokers of low-yield cigarettes, Kozlowski 
et al. (1982a) observed hole-blocking behavior and measured tar, nicotine, 
and CO levels. The investigators reported that 44 percent of 39 smokers of 
low-yield cigarettes blocked the ventilation holes to various degrees with 
their fingers or lips; 5 of 33 females left hole-blocking lipstick on the filters. 
In the second part of their study, Kozlowski and colleagues (1982a) 
evaluated the effect of hole blocking on the tar, nicotine, and CO yields of 
American, British, and Canadian cigarettes of lowest or near-lowest yields. 
After videotaping 48 smokers, the researchers defined actual smoking 
behaviors and reset smoking machine parameters to reflect these real-life 
patterns for puff interval (44 seconds) and puff duration (2.4 seconds). 
Machine [)uff volume was set at 47 ml. (2 to 13 ml, below the smokers' 
estimated average) because this is the maximum obtainable from most 
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