Nicotine regulates smoking patterns.
ABSTRACT Since 1953, the sales-weighted average "tar" and nicotine yields of commercial cigarettes in developed countries have significantly declined. However, the risk for chronic obstructive pulmonary disease (COPD) and for cancer of the lung has not decreased; adenocarcinoma incidence even continues to rise faster than the rate of squamous cell carcinoma of the lung. Undiminished risk of cigarette smokers for COPD and lung cancer is largely due to more intense smoking and deeper inhalation of the smoke of "low-yield" cigarettes and to significant changes in the smoke yields of certain lung carcinogens.
Puff frequency, puff duration, and puff volume of cigarette smokers were determined by a microcomputer-assisted flow transducer. These parameters were then programmed into a smoking machine to generate mainstream smoke for quantifying nicotine and lung carcinogens.
Simulating the human smoking characteristics increases the yields of "tar" and nicotine per cigarette two- to threefold above Federal Trade Commission-reported levels. Smoke yields of lung carcinogens like benzo[alpha]pyrene and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone parallel those of nicotine and "tar."
The way people smoke and the total number of cigarettes consumed daily determine the uptake, i.e., the administered dose of nicotine, other toxic, and genotoxic smoke constituents. It is important to communicate this to consumers rather than letting the smokers believe that they are truly smoking a cigarette of lower smoke yields when they choose "light" or "ultralight" products.
- SourceAvailable from: dccps.cancer.gov[show abstract] [hide abstract]
ABSTRACT: INTRODUCTION Since the first epidemiological reports on the association of cigarette smoking with lung cancer, the composition of tobacco blends and the makeup of commercial cigarettes in the United States as well as in Western Europe have undergone major changes. Measured on the basis of standardized machine smoking conditions, the sales-weighted average tar and nicotine deliveries in U.S. cigarette smoke have decreased from 38 mg and 2.7 mg, respectively, in 1954 to 12 mg and 0.95 mg, respectively, in 1993. The lower emissions have been primarily accomplished by using efficient filter tips and highly porous cigarette paper and by changing the composition of the tobacco blend. The latter includes the incorporation of reconstituted and expanded tobaccos into the blend. Concurrent with the reduction of tar and nicotine in the smokestream, there also occurred a reduction of carbon monoxide, phenols, and carcinogenic polynuclear aromatic hydrocarbons (PAHs). These reductions were partially tied to an increase in the nitrate content of the tobacco blend used for U.S. cigarettes. The addition of nitrate was initially targeted at decreasing the smoke yields of PAHs; however, that this also would cause a gradual increase of the carcinogenic, tobacco-specific N-nitrosamines (TSNAs) was not recognized until there was awareness of those compounds as smoke constituents in the 1970's. These observations were based on measurements of yields from cigarettes that were smoked under standardized laboratory conditions, initially established in 1936, and adopted by the U.S. Federal Trade Commission (FTC) in 1969. These conditions do not reflect the smoking patterns of the smokers of filter cigarettes, who currently account for the consumption of 97 percent of all cigarettes produced in the United States. The current filter cigarette smoker tends to smoke more intensely and to inhale more deeply. Thus, the actual exposure to toxic and tumorigenic agents in the inhaled smoke of filter cigarettes is not necessarily in line with the machine smoking data.
- [show abstract] [hide abstract]
ABSTRACT: A case-control study of lung cancer involving interviews with 7,804 cases and 15,207 hospital-based controls was carried out in seven locations in Western Europe. The large study size permitted the calculation of precise estimates of the relative risk of lung cancer associated with smoking different types of cigarettes. Lifelong nonfilter smokers were at nearly twice the risk of lung cancer compared to lifelong filter smokers after controlling for duration of cigarette use and number smoked per day (RR = 1.7 for males and 2.0 for females). Lung cancer risks for filter, nonfilter and mixed smokers increased in proportion to intensity and duration of smoking and decreased with years since stopping smoking. The findings indicate that prevention activities should continue to emphasize smoking cessation, although switching to low-tar cigarettes may also yield some reductions in lung cancer risk.International Journal of Cancer 06/1984; 33(5):569-76. · 6.20 Impact Factor