Volumen 22 (2007): Heft 5 (June 2007)

The unexpected death of Richard Baker at Easter of this year was a shock for all who knew him. It was just in the last Issue of the Journal (Volume 22, No. 4, January 2007) that we as Editors were pleased and proud to print the laudation by Thomas A. Perfetti of Richard Baker who received the 2006 Tobacco Science Research Conference Lifetime Achievement Award. In this Issue, we have the sad duty to print an obituary for Richard Baker. We have asked Ray Thornton, a former Scientific and Regulatory Manager at BAT to write the obituary, because Ray was a colleague, neighbour and friend of Richard Baker.

BeiträgezurTabakforschung International/Contributions to Tobacco Research has lost one of its most dedicated and productive Advisory Board Member. Richard Baker was member of the Advisory Board since 1994. He has thoroughly reviewed numerous manuscripts submitted to the Journal. He also convinced many authors of tobacco- or smoke- related papers from inside and outside the Tobacco Industry to submit their manuscripts to the Journal. The Advisory Board Members of the Journal will remember his well-founded and also humorous contributions at the yearly or biennial meetings.

We, as Editors, want to state: Richard Baker has rendered outstanding services to the Journal, we shall miss him very much.

Richard Baker died at Easter 2007 after a very short illness. It is sad that he died so soon after his retirement from the British American Tobacco Company at the end of 2005, and just as he was beginning to enjoy his new life, even though tobacco science still had a part to play.

In 2006 Richard received the Tobacco Science Research Conference Lifetime Achievement Award, and at this time Thomas Perfetti, in this journal, described his distinguished scientific career in some detail. I will not repeat the list of these remarkable achievements, but can only add that he may well be the only scientist ever to be awarded the ultimate research degree, a D. Sc., by a British University for research activities while working for a tobacco company. Bearing in mind anti-tobacco sentiment this was a breath-taking achievement.

Richard joined B.A.T. in 1971 and came to live quite near us on the outskirts of Southampton. We got to know Richard and Jackie well. Being a few years older several of the younger Thornton's then acted as baby-sitters as the younger Baker's appeared on the scene. Richard's enthusiasm for jogging and long-distance running was well known. As he jogged by the entrance to my house on foggy mornings he became a well-known health hazard, both to himself and to me.

Richard's interests also included local politics and schools and indicated his great interest in people and their well-being. He was a kind and thoughtful colleague. When we moved house in 1976 Richard and Jackie sent us a good luck card, repeated in 1994 when we moved, briefly and spectacularly, to New Delhi.

Richard's last years were evidently as full as ever, and he was still publishing scientific papers in his role as a Consultant. He was close to his family and children. Grandchildren, of whom he was very fond, had arrived. Richard and Jackie had also acquired a holiday home in their beloved Lake District in N.W. England.

I, and everyone who met him, will have fond recollections of Richard as a delightful person and as an outstanding scientist, and above all we would like Jackie to know how we regarded him.

For nearly four decades, the expansion of tobacco has been recognized as one of eight technologies significant in the design of a ‘less hazardous’ cigarette. The data previously presented at scientific conferences and/or published in several scientific monographs and journals on the effect of the expansion of tobacco on the composition and biological properties of the mainstream smoke from cigarettes containing it are summarized. In addition, previously unpublished data on the same subjects are presented in considerable detail. Included are 1) the effect of tobacco expansion on the yields of total particulate matter (TPM), nicotine, and several hundred components of cigarette mainstream smoke from control tobacco cigarettes vs. expanded tobacco cigarettes; 2) the changes in mainstream smoke yields of total particulate matter, nicotine, and specific smoke components produced by inclusion of various levels of expanded tobacco in a cigarette blend; and 3) the changes in composition of expanded tobacco. In the latter study, the decrease in levels of numerous significant flavorful components of the tobacco produced by expansion provides the need for inclusion of such compounds in flavor formulations. In study 2), the reductions in per cigarette yields of total particulate matter, nicotine, and several components of concern were determined and confirmed the significance of tobacco expansion as a cigarette design technology to produce what was originally defined as a ‘less hazardous’ cigarette but more recently as a ‘potential reduced exposure product’ (PREP).

This paper presents the findings on a quantitative evaluation of carbonyl levels in exhaled cigarette smoke from human subjects. The cigarettes evaluated include products with 5.0 mg ‘tar’, 10.6 mg ‘tar’ and 16.2 mg ‘tar’, where ‘tar’ is defined as the weight of total wet particulate matter (TPM) minus the weight of nicotine and water, and the cigarettes are smoked following U.S. Federal Trade Commission (FTC) recommendations. The measured levels of carbonyls in the exhaled smoke were compared with calculated yields of carbonyls in the inhaled smoke and a retention efficiency was obtained. The number of human subjects included a total of ten smokers for the 10.6 mg ‘tar’, five for the 16.2 mg ‘tar’, and five for the 5.0 mg ‘tar’ product, each subject smoking three cigarettes. The analyzed carbonyl compounds included several aldehydes (formaldehyde, acetaldehyde, acrolein, propionaldehyde, crotonaldehyde and n-butyraldehyde), and two ketones (acetone and 2-butanone). The smoke collection from the human subjects was vacuum assisted. Exhaled smoke was collected on Cambridge pads pretreated with a solution of dinitrophenylhydrazine (DNPH) followed by high performance liquid chromatography (HPLC) analysis of the dinitrophenylhydrazones of the carbonyl compounds. The cigarette butts from the smokers were collected and analyzed for nicotine. The nicotine levels for the cigarette butts from the smokers were used to calculate the level of carbonyls in the inhaled smoke, based on calibration curves. These were generated separately by analyzing the carbonyls in smoke and the nicotine in the cigarette butts obtained by machine smoking under different puffing regimes. The comparison of the level of carbonyl compounds in exhaled smoke with that from the inhaled smoke showed high retention of all the carbonyls. The retention of aldehydes was above 95% for all three different ‘tar’ levels cigarettes. The ketones were retained with a slightly lower efficiency. Acetone was retained in the range of 90% to 95%. The retention for 2-butanone showed a larger scatter compared to other results but it also appeared to be slightly less absorbed than the aldehydes, with an average retention around 95%. The retention of acetaldehyde and acetone by human smokers was previously reported in literature and the findings from this study are in very good agreement with these result.

A mathematical model on the temperature and oxygen profiles for the tobacco warehouse aging process was formulated and solved by numeric analysis. The model parameters were obtained using the non-linear regression method by fitting several years measured temperatures to the model. The R square value between measured and calculated tobacco temperatures in warehouse aging process are all over 0.95. The proposed model can be used to predict the tobacco hogshead temperature profile at different time and positions with ambient temperature, tobacco moisture contents and pH. At the same time, the model also predicts the oxygen profile in the hogshead. The effects of the ambient temperature, pH, void fraction, the reaction active energy, oxygen diffusivity, and the oxygen consumption rate constant on the temperature profile were studied.