772 



Cigarette Yields of Tar and Nicotine and IMaricers 

 of Exposure to Tobacco Smoice 



DAVID B. COULTAS, CHRISTINE A. STIDLEY, and JONATHAN M. SAMET 



Department of Medicine, Pulmonary and Critical Care Division, and the New Mexico Tumor Registry, Cancer Center, 

 University of New Mexico School of Medicine, Albuquerque, New Mexico 



Although cigarette yields of tar and nicotine have been declining since the eady 1970s, little information 

 is available for the general population on the consequences of their use on exposure to tobacco combus- 

 tion products. In a population-based sample of 298 smokers, the majority of whom were IHispanic, we exam- 

 ined the relationships between yields of cigarettes cunently smoked and levels of salivary cotinine and 

 end-expired carbon monoxide. Spearman correlation coefficients between the current number of cigarettes 

 smoked and cotinine (r = 0.52) or carbon monoxide (r = 0.51) were higher than correlations between the 

 Federal Trade Commission (FTC) nicotine data and these same markets, 0.12 and 0.05, respectively Corre- 

 lations tmtween FTC tar and cartjon monoxide yields and the biologic markers were similarly weak. In mul- 

 tiple linear regression models, the current number of cigarettes smoked was the most important predictor 

 of cotinine and cartx>n monoxide levels (p < 0.0001). The addition of FTC tar, nicotine, or carbon monoxide 

 to the models explained little of the variability in cotinine or carbon monoxide levels. Because FTC yields 

 of tar and nicotine are poor predictors of exposure to tobacco combustion products, subjects^ reports of 

 cigarette brand should not be used as a primary marker of exposure in epidemiologic investigations. Fur- 

 thermore, smokers need to be advised atiout the limitations of cigarette yield information for predicting 

 the potential for adverse health effects of smoking. Coultas DB, Stidley CA, Samel JM. Cigarette yields 

 of tar and nicotine and markers of expoiure to tobacco smoke. Am Rev Respir DIs 1 993; 1 48:435-40. 



Since the early 1970s, tobacco manufacturers have marketed cig- 

 arettes with increasingly lower tar and nicotine yields (1). Marketers 

 have implied that health benefits accrue from low-yield cigarettes, 

 and switching to these cigarettes has been advocated for smokers 

 unwilling to quit (2). These well-advertised changes in cigarettes 

 have led to the belief by as many as 45% of smokers that low- 

 yield cigarettes are less hazardous than other cigarettes (3). Be- 

 cause cigarette tar and nicotine yields are determined with smok- 

 ing machines, however, the data may not accurately reflect the 

 exposures to tobacco combustion products actually experienced 

 by smokers (4). To develop effective preventive strategies for 

 cigarette-related diseases, evidence is needed on the relation- 

 ship between the reported yield to tar and nicotine and levels of 

 biomarkers, which may provide a more biologically appropriate 

 index of the doses of injurious substances. 



Using data from a population-based survey of respiratory dis- 

 eases and lung function in New Mexico Hispanics (5), we de- 

 scribed the tar and nicotine yields of cigarettes smoked, based 

 on respondents' reports of brands and Federal Trade Commission 



[Received in original form lune 29, 1 992 and m revned form December f 4, J 992} 

 Supported by Grant No. HL-28120 from thie Division of l^ng Diseases. Na- 

 tional Heart. Lung, and Blood Institute and by Contract No. NO! -CN-55426 

 from the Biofnetry Branch, National Cancer institute. 

 Correspondence and requests for repnnts should t>e addressed to Oavid B. 

 Coultas, M.D., Universtly of New Mexico School ol Medicine, New Memco 

 Tumor Registry, 900 Camino de Salud, Albuquerque, NM 8713). 

 Dr. Coultas is the reapient of Preventive Pulmonary Academic Award No. K07- 

 HL02474 from the National Heart. Lung, and Blood institute. 



Am Rev Resptr Oil Vol 14<. pp 43S-4«>, 1991 



(FTC) data, and examined the relationships of measures of ciga- 

 rette smoke exposure, including current number of cigarettes 

 smoked per day and FTC cigarette yields, with levels of salivary 

 cotinine and end-expired cart>on monoxide. Our intent was to ex- 

 amine, in a population-based sample, the relationships between 

 these biomarkers of exposure and the FTC values 



METHODS 

 Data Collection 



The study was conducted in a semirural city with a 1960 population of 

 more than 1 1 .000 located near Albuquerque, H&m Mexico. The methods 

 of sample selection and data collectkm and the study questionnaires were 

 descnt>ed in detail by Samet and colleagues (5). In the period from July 

 1984 to NovemtMr 1985, 733 Hispanic househoMs were sampled in a 

 population-based prevalence survey of respiratory disease. Household 

 eligibility was based on ttie presence of at least one self-identified Hispanic 

 adult. Ail persons residing in the household were considered eligibte to 

 participate in the study regardless of ethnicity. Survey procedures rele- 

 vant for this analysis included an interviewer-administered smoking his- 

 tory for persons 18 yr of age and okJer, endmdal cartx>n monoxide deter- 

 mination, and collection of a saliva sample at the time of data cotlectton 



End-exptred samples of exhaled air were oCrtained for n>easurement 

 of cartwn monoxide (6). Subjects inhaled to total tung capacity from func- 

 tional residual capacity and hekj the breath for 10 s. The sut>fects then 

 exhaled, and the field interviewer collected the exhaled air close to func- 

 tional residual capacity in a 1-L anesthesia bag fitted with a one-way valve. 

 Within 2 h the end-expired air samples were analyzed at the field office 

 for cartxsn monoxide with an Ecolyzar* (Energetics Science. Hawthorne, 

 NY), whicii was calibrated daily witts a 40 ppm cartxin monoxide stan- 

 dard. An e4hanol filter was used to prevent interference 



The salhra was collected by expectoration of 1 to 2 ml into a plastic 



