A Model To Estimate the Sources of Tobacco-Specific Nitrosamines in Cigarette Smoke.

Tobacco-specific nitrosamines (TSNAs) are one of the most extensively and continually studied classes of compounds found in tobacco and cigarette smoke.1-5 The TSNAs N-nitrosonornicotine (NNN) and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) have been characterized by the US Food and Drug Administration (FDA) as harmful and potentially harmful constituents in tobacco products,6 and cigarette manufacturers report their levels in cigarette tobacco filler and cigarette smoke to the FDA. NNN and NNK are classified by IARC as carcinogenic to humans.

Method for the Determination of Carbonyl Compounds in E-Cigarette Aerosols.

Low levels of thermal degradation products such as carbonyls (formaldehyde, acetaldehyde, acrolein, crotonaldehyde) have been reported in e-cigarette aerosols. The collection and analysis of e-cigarette aerosol carbonyls are often adapted from methods developed for tobacco cigarette smoke. These methodologies are often not sensitive enough to detect low carbonyl levels in e-cigarette aerosols.

Time trends in never smokers in the relative frequency of the different histological types of lung cancer, in particular adenocarcinoma.

The increasing proportion of lung cancers classified as adenocarcinoma has been a topic of interest and research. The main objective of the analyses reported here is to summarize how the proportion of adenocarcinoma varies in never smokers by time, sex and region based on published evidence on the distribution of lung cancer types available from epidemiological studies. Based on 219 sex- and period-specific blocks of data drawn from 157 publications, there appears to be a clear time-related increase in the proportion of lung cancers in never smokers that are adenocarcinoma, which is evident in both sexes, and not specific to any region.

Effect of cigarette design on biomarkers of exposure, puffing topography and respiratory parameters.

Despite the lack of evidence, many reports exist which have implied that smokers inhale low-yield cigarette smoke more deeply than that of high-yield cigarettes. The objective of this study was to investigate the effect of short-term switching between smoker's own brand and test cigarettes with different smoke yields on puffing topography, respiratory parameters and biomarkers of exposure. Participants were randomly assigned to smoke either a Test Cigarette-High Tar (TCH), for two days, and then switched to a Test Cigarette-Low Tar (TCL), for two days or the reverse order (n = 10 each sequence).

TSNA exposure from cigarette smoking: 18 years of urinary NNAL excretion data.

The objective of this work was to characterize trends over time in urinary excretion of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) among cigarette smokers in the US. We identified 35 studies presenting data that either reported, or could be converted to, common units of total urinary NNAL excretion as pmol/mg creatinine. The studies spanned 18years, reported urinary NNAL excretion estimates for 61 defined populations, and included a combined total of 3941 study participants.

TSNA levels in machine-generated mainstream cigarette smoke: 35 years of data.

This paper characterizes historical and current tobacco specific nitrosamine (TSNA) levels in mainstream (MS) cigarette smoke of US commercial cigarettes. To conduct this analysis, we gathered 35 years of published data of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N-nitrosonornicotine (NNN) levels in MS cigarette smoke. We also assessed internal data of MS smoke NNK and NNN levels generated from various market monitoring initiatives and from control cigarettes used in a multi-year program for testing cigarette ingredients.

The effect of cigarette burn time on exposure to nicotine and carbon monoxide in adult smokers.

Cigarette burn time (CBT), conventionally defined as the time a cigarette burns during smoking, can be affected by cigarette design and smoking behavior. A previous study showed a strong negative correlation between CBT and nicotine yield under machine smoking conditions. This study for the first time examined the relationship of CBT and exposure to nicotine and carbon monoxide in adult smokers in a controlled clinical study.

On the deposition of volatiles and semivolatiles from cigarette smoke aerosols: relative rates of transfer of nicotine and ammonia from particles to the gas phase.

The hypothesis that elevated levels of ammonia-releasing compounds in tobacco and ammonia in mainstream (MS) smoke increase the rate and amount of nicotine evaporation from the particles of MS smoke aerosol was examined by kinetic modeling and experiments with MS cigarette smoke. Computational simulation of a kinetic mechanism describing volatile loss of nicotine, ammonia, and acetic acid from an aqueous solution was used to compute the time-dependent concentration of all species in the model. Because of the high volatility of ammonia relative to that of nicotine, variation over a wide range of initial ammonia concentration had no significant effect upon the rate of loss of nicotine from the model system.