Chapter 12 
The short-term study by Zacny and Stitzer (1988) (not included in our 
review) examined smokers who had been given three different lower yield 
brands (i.e., 0.1 mg, 0.4 mg, 0.7 mg nicotine). This study produced a pattern 
of compensation similar to that in Figure 1. 
For consumers, the average percentage compensation may be less 
important than the likelihood of substantial compensation. If 1 in 2, 1 in 5, 
1 in 10, 1 in 50, or even 1 in 100 smokers shows compensation of 25, 33, 55, 
or 75 percent, then a problem exists. If automobile brakes failed at a rate of 
even 1 in 1,000, this rate would be of great concern to manufacturers, 
consumers, and regulatory agencies. 
ONE REPEATED- Lynch and Benowitz (1987) conducted a self-selected brand- 
MEASURES STUDY switching study of participants who spontaneously switched 
OF SELF-SELECTED cigarette brands. The study included 62 people who had 
BRAND SWITCHING lowered their standard yield. When they had been studied 
earlier, they had had plasma measures taken, and they were recontacted 3 to 
6 years later. In this group, the low-yield cigarette was 62 percent of the 
former usual cigarette yield of nicotine (.68 mg versus 1.09 mg). Plasma 
cotinine per cigarette was unchanged: 10.3 ng per mL for the low-yield 
cigarette versus 10.2 ng per mL for the former usual cigarette. This represents 
a compensation of 103 percent! 
SMOKERS CAN GET 
HIGH YIELDS FROM 
THE LOWEST OF 
THE LOW-YIELD 
CIGARETTES: 
MORE ON THE 
ISSUE OF VENT 
BLOCKING 
Some points should be made about vent blocking and the 
possibility of getting high yields from ultralow-yield brands. 
In one study, 14 people were smoking ultralow-yield cigarettes 
(Kozlowski et al., 1989), and half the smokers were vent 
blockers. Two of the seven vent blockers smoked about 
25 cigarettes per day and each blocker showed carbon 
monoxide scores of 37 parts per million, which are very high. 
Salivary cotinine levels of 303 and 385 ng per mL, from a 
nominally .01-mg nicotine cigarette, are also very high. Therefore, there 
were high exposures from a very-low-yield cigarette, clear evidence that some 
smokers — if only two — were able to get substantial levels from the lowest of 
the low-yield cigarettes. 
Some submissions from the cigarette industry have indicated that vent 
blocking is not a substantial problem. In contrast, four laboratories have 
produced eight peer-reviewed studies that found evidence of vent blocking 
(Hofer et al., 1991; Kozlowski et al., 1982a, 1988, 1989, and 1994; Lombardo 
et al., 1983; Robinson et al., 1983; Zacny and Stitzer, 1988). In these studies, 
the prevalence of "extreme" vent blocking ranged from 1 to 210 per 1,000 
(median = 19 percent), and the prevalence of "at least some blocking" ranged 
from 61 to 580 per 1,000 (median = 50 percent). 
One submission from the cigarette industry notes that ventilation has 
changed a great deal recently. However, invisible laser ventilation has been 
available for at least a decade. From a consumer's point of view, it is unclear 
why invisible ventilation techniques should be viewed as appropriate. 
i 
165 
