Volume 24 (2010): Edition 3 (November 2010)

We would like to draw our readers‘ attention to the following three joint publications in this issue:

· HAHN and SCHAUB (page 100)

· ROEMER et al. (page 117)

· INTORP et al. (page 139)

The three papers are based on an initiative of the German regulative authorities who requested and initiated a research project to get more information concerning the influence of tobacco additives on the composition of cigarette mainstream smoke. Since up to now, most of the peer reviewed publications on the effects of additives originate from scientists based in the tobacco industry, in this case an independent regulative laboratory (Chemical and Veterinary Surveillance Agency Sigmaringen) was asked to evaluate the effects of the tobacco additives sucrose, cocoa powder and glycerol on the amounts of several selected compounds in cigarette mainstream smoke. The test cigarettes for these evaluations were manufactured in the pilot plant of BAT Germany and are described and characterized by HAHN and SCHAUB. This paper also contains the results of the regulatory laboratory on the effects of the three additives on mainstream smoke composition.

The influence of these additives on cigarette mainstream smoke was also evaluated by ROEMER et al. and INTORP et al. using the identical test cigarettes as studied by HAHN and SCHAUB. While INTORP et al. in their three laboratory study analyzed the same mainstream smoke component as HAHN and SCHAUB, ROEMER et al. studied the effects of these tobacco ingredients on the levels of 39 different components in mainstream smoke of the test cigarettes and also on different endpoints of some selected toxicological in vitro assays. The chemical analytical work necessary for this evaluation was done by Labstat International, an independent contract laboratory; the in vitro tests were done by the Philip Morris Research Laboratories, Cologne, Germany. The results obtained by the participating laboratories showed no overall significant effects of the tested additives on the levels of the selected smoke constituents and the biological activity.

Finally, we would like to inform our readers that Nicolas Baskevitch has decided to retire from the advisory board, being a member since 2006. We would like to thank him for his collaboration in improving the manuscripts submitted to the Journal.

Additives used in tobacco product manufacturing are currently in the focus of public discussions with regard to potentially increased consumer health risks on account of certain additives. In addition, a few additives are suspected to enhance the addictiveness of tobacco products. In 2006, the German Federal Ministry for Food, Agriculture and Consumer Protection (BundesministeriumfuerErnaehrung, Landwirtschaft und Verbraucherschutz, BMELV) commissioned a research project intended to provide support for the evaluation of additives and their influence on the composition and properties of cigarette mainstream smoke. In this paper the results of the study are reported. Different amounts of glycerol, cocoa powder and sucrose were added to the tobacco of two kinds of filter-ventilated King size test cigarettes with ‘tar’ levels of 6 mg and 10 mg per cigarette. The tobacco of the test cigarettes consisted of a commercially available blend made of Virginia, Burley and Oriental tobaccos. Machine smoking was performed according to the applicable ISO smoking regimen. Various smoke components, which are suspected to be harmful for health, were determined in mainstream smoke. Increasing levels of sucrose were correlated with an increase of the amount of formaldehyde but not of acetaldehyde in the mainstream smoke of the test cigarettes. In cigarettes with different levels of added glycerol no substantial change in smoke composition was observed. The addition of cocoa powder to tobacco resulted in a decrease of tobaccospecific N-nitrosamines in mainstream smoke. The results obtained in this study can be used as evidence for the toxicological evaluation aimed at approving or banning specific additives for tobacco product manufacturing.

The cigarette ingredients cocoa powder, glycerol, and saccharose were investigated regarding their potential effect on the resulting mainstream smoke, i.e., smoke chemistry (Hoffmann analytes), mammalian cell cytotoxicity (Neutral Red Uptake assay), and bacterial mutagenicity (Ames assay). Each ingredient was added at three concentrations to the tobacco of a 6 mg and 10 mg ‘tar’ yield experimental American blend filter cigarette (obtained under ISO/FTC smoking regime). The lowest application concentration was equivalent to the normal approximate use level of the ingredients; the highest application level was up to 5-fold higher. The resulting data were compared with the respective control cigarettes without addition of the ingredients. The addition of cocoa powder did not lead to any consistent effects on the measured mainstream smoke analytes. Neither the in vitro cytotoxicity nor the in vitro mutagenicity was affected by cocoa addition. The addition of glycerol resulted in a decrease in the delivery of several smoke constituents (generally around 20%), e.g. aldehydes, phenolics, and N-nitrosamines. Water in the particulate phase (TPM) was distinctly increased (up to +150%). The cytotoxicity of the TPM was decreased (approx. !15%). Mutagenicity was not affected. Saccharose addition consistently increased formaldehyde delivery in smoke by up to 40% and decreased tobacco-specific N-nitrosamines by up to approximately 20%. The increase in formaldehyde is discussed in the context of the human smoker. The cytotoxicity was not affected by the addition of saccharose, while the mutagenicity of the TPM was decreased in tester strain TA98 with metabolic activation (!15%). The results are in agreement with currently available literature. Some investigations summarized in this publication are novel and have not yet been reported in the literature. Based on the total evidence, it can be concluded that the three ingredients added at their current use levels do not increase the inherent toxicity of the cigarette smoke.

Three tobacco industry based laboratories determined selected mainstream components using their established in-house methods. Machine smoking was done according to the ISO smoking regime. The Test cigarettes smoked for this investigation were manufactured with different amounts of added glycerol, cocoa powder and sucrose. Variability between the three laboratories differed clearly for the analyzed smoke components. No overall effects due to the added ingredients on smoke components could be found. The high ‘tar’ products with the highest lodading of sucrose showed a slight increase in formaldehyde emissions among all three laboratories.

A simple procedure for the collection of vapor phase (VP) of mainstream cigarette smoke for analysis has been developed. This procedure consists of collecting the VP on a commercial charcoal trap (ORBO™-32) followed by dissolution in acetone. The acetone extract can be analyzed by a gas chromatography/mass spectrometry (GC/MS) technique. A qualitative analysis of the collected VP has been performed for 3R4F Kentucky reference cigarette, allowing the identification of 138 compounds, some compounds being present in both VP and in particulate phase (PP) of cigarette smoke. A quantitative analysis method for acrylonitrile and α-methacrylonitrile (2-methyl-2-propenenitrile) was also developed, and the level of these compounds in 15 different cigarette brands was measured. Acrylonitrile quantitation was selected since this compound in smoke poses significant health related issues. α-Methacrylonitrile quantitation was selected due to the similar structure of this compound with acrylonitrile. The analyzed cigarettes were several Kentucky reference cigarettes including 1R5F, 2R4F, 3R4F, 2R1F, and 1R3F, several King Size (KS) commercial cigarettes from the US market including Basic Non Filter (NF), Basic Ultra Lights (UL), Newport, Marlboro (Red), Marlboro Menthol, Camel Filter, Camel Lights, Camel Ultra Lights, and two herbal cigarettes, Ecstasy and Dreams. The results for acrylonitrile were in very good agreement with data reported in the literature for 2R4F and 1R5F cigarettes. The levels of α-methacrylonitrile were not previously reported. The correlation between the levels of acrylonitrile and of α-methacrylonitrile with the (wet) total particulate matter (TPM) was evaluated. Although the levels of acrylonitrile and of α-methacrylonitrile in mainstream smoke depend on the TPM values, the correlation is not very strong, indicating that the nature of the cigarette blend and possible other factors in cigarette construction also influence their levels in smoke. The collection method used in this study allows the subsequent dissolution of VP in a much smaller volume of solvent compared to other methods that use impingers, allows the use of standard GC/MS autosamplers for liquid injection and simple addition of internal standards compared to the methods that use gas bags, and allows a simple and immediate collection of VP as it leaves the Cambridge filter pad. These characteristics represent significant advantages versus other methods commonly used for VP analysis.