Peter J. Lipowicz

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. In all, we analyzed machine smoking data from 401 cigarette samples representing a wide range of products and design characteristics from multiple manufacturers and market leaders. There was no indication that TSNA levels systematically increased in cigarette MS smoke over the 35-year analysis period. In particular, TSNA levels expressed as either per cigarette or normalized for tar suggest a downward trend in MS smoke over the past 10 years. The apparent downward trend in TSNA levels in MS smoke may reflect industry and agricultural community efforts to reduce levels of TSNAs in tobacco and cigarette smoke.

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. It is seen whether the denominator of the proportion is made up of adenocarcinoma plus squamous cell carcinoma cases, cases of the four major types combined, or all lung cancer cases. The ratio of adenocarcinoma to squamous cell carcinoma rose continuously from 1950 to 69 to be almost 4 times higher for the data from 2000 onwards. We discuss factors that may have contributed to the observed findings, including changes in lung cancer classification. Our findings argue against the hypothesis that increases in the ratio arise from changes in cigarette design and composition.

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. Analyses show that urinary NNAL excretion trends downward with study publication year, and the trend is statistically significant. The trend does not appear to be accounted for by a reduction in cigarettes smoked per day by study participants over the same time period. This trend is consistent with reductions in tobacco specific nitrosamine (TSNA) levels in both cigarette tobacco filler and mainstream cigarette smoke observed over the past decade and with efforts by the tobacco industry and the agricultural community to reduce levels of TSNAs in tobacco and cigarette smoke.

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

Abstract 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). Puffing topography (CReSS microdevice), respiratory parameters (inductive plethysmography) and biomarkers of exposure (BOE, urinary nicotine equivalents – NE and blood carboxyhemoglobin – COHb) were measured at baseline and on days 2 and 4. The average puffs per cigarette, puff volume and puff durations were statistically significantly lower, and inter-puff interval was significantly longer for the TCH compared to the TCL groups. Respiratory parameters were not statistically significantly different between the TCH and TCL groups. Post-baseline NE and COHb were statistically significantly lower in the TCL compared to the TCH groups. Under the conditions of this study, we found no indication of changes in respiratory parameters, particularly inhalation time and volume, between study participants smoking lower versus higher yield cigarettes. Likewise, the BOE provides no indication of deeper inhalation when smoking low- versus high-yield cigarettes. These findings are consistent with the published literature indicating smoking low-yield cigarettes does not increase the depth of inhalation.