Volume 26 (2015): Issue 7 (September 2015)

Causal determination in cases of diseases involving multiple risk factors and long development time poses formidable challenges to judges and juries. Numerous scientific, medical and legal questions are involved. For example, is the mere presence of a factor known to be associated with elevated disease risk sufficient for a causal determination? If not, what level of exposure should be deemed sufficient, and how can that exposure be measured with adequate confidence over an extended period? In the presence of two or more factors associated with elevated disease risk, how can causation be demonstrated and apportioned among these factors, particularly when the potential effects of their interaction are unknown? With increasing knowledge of the molecular and genetic changes involved in disease development, what level of comprehension and proof is sufficient to implicate a specific risk factor in the complex causal mechanism of an individual’s disease? Lung cancer, notwithstanding its strong association with cigarette smoking, represents a group of diseases associated with both a variety of risk factors and relatively long development time. Both the published scientific literature and current clinical practice for the treatment of lung cancer, particularly lung adenocarcinoma, reflect the rapid changes that have occurred in this field over the past decade. These medical advances, in addition to promising better prognosis for some lung cancer patients, have implications for the proof of lung cancer causation in litigation in which plaintiffs contend that tobacco smoke exposure caused their disease. This is particularly true in cases arising in many European countries and other jurisdictions in which little or no histological or cytological information has been produced by plaintiffs. This paper examines the rapidly evolving science underpinning lung cancer diagnosis and treatment and its forensic implications. [Beitr. Tabakforsch. Int. 26 (2015) 298-311]

The pore size distribution of cigarette paper determines its air permeability and diffusion capacity and thereby has a significant influence on the gas exchange of a cigarette through the cigarette paper during smoking and during smouldering. For the design of cigarettes and in particular of cigarette papers it is important to understand how the pore size distribution of the cigarette paper is affected by the paper composition and paper properties and how it influences air permeability and diffusion capacity.

It was the aim of this study to investigate how the composition of the cigarette paper such as filler content, fibre type and burn additive content qualitatively influenced the pore size distribution and how the pore size distribution and, in particular, which pore size range is correlated with air permeability and diffusion capacity, respectively. To this end eight naturally porous cigarette papers were selected which differed in air permeability, diffusion capacity, fibre type, filler content and burn additive content. The pore size distributions of these papers were measured by mercury porosimetry before and after the papers had been heated to 230 °C for 30 min. The pore size distributions were investigated for qualitative differences when air permeability, fibre type and filler content of the cigarette paper are modified. Furthermore by appropriate weighting of the pore size distributions optimal correlations between a weighted pore volume and air permeability or diffusion capacity were determined. The results show a good correlation with correlation coefficients greater than 0.9 for air permeability as well as for diffusion capacity. The results indicate that large pores are better correlated with changes in air permeability, while small pores are more strongly correlated with changes in diffusion capacity and support previous theoretical results obtained from flow and diffusion models. They also demonstrate the tight relationship between pore size distribution, air permeability and diffusion capacity, which makes the pore size distribution a tool to further optimize cigarette papers, for example, with respect to carbon monoxide yields in the smoke of a cigarette. [Beitr. Tabakforsch. Int 26 (2015) 312-319]

“Tar”, nicotine and carbon monoxide (TNCO) cigarette yields determined under different smoking regimes, with and without ventilation blocking, are linearly related to the difference Δt between the smouldering time (cigarette combustion with no puffing) and the smoking time (cigarette combustion with puffing). Δt forms then the basis of yield predictions. The smoulder rate determination used in the calculation of Δt can be difficult for low ignition propensity cigarettes which present some tendency for selfextinguishment. This issue was overcome in a novel testing scheme involving the determination of number of puffs and smoking times under two different smoking regimes and inputting this data into a cigarette burning model. This enabled us to characterise the burning process and provided an extensive set of information such as the mean smoulder rate between puffs or the mass of tobacco burnt during puffs regardless of the smoking regime applied.

Good correlations were observed between the mass of tobacco burnt during puffs and TNCO or B[a]P yields. Correlations provide a way to link yields from one smoking regime to another and confirm that yields determined from one regime are sufficient to establish the relationships between yields and smoking intensity. It was concluded that smoke yields for arbitrary smoking regimes can potentially be predicted by determining the puff numbers and smoking times from two different smoking regimes and the smoke yields from only one regime. This testing scheme allows a comprehensive characterisation of a cigarette at reduced cost. [Beitr. Tabakforsch. Int. 26 (2015) 320-333]

The present study describes a reliable technique for the analysis of free amino acids in tobacco leaf. The levels of amino acids in tobacco are important since they are related to both tobacco quality and the potential generation in cigarette smoke of toxicants having amino acid precursors. Other techniques used in the past for amino acid analysis have various shortcomings that were avoided in the present method. The new method uses HPLC separation and a tandem mass spectrometer for detection with no derivatization step as sample preparation. The separation has been obtained using ion pair HPLC on a reversed phase column that offers excellent chromatographic resolution. The MS/MS detection procedure offers very good sensitivity and positive identification of the analytes. The procedure was fully validated and can be used for the analysis of 24 amino acids. It was applied for the quantitation of amino acids from 16 types of tobacco including flue-cured and Burley, some domestic and some not grown in the USA, two types of Oriental tobacco, and from tobacco of a 3R4F Kentucky reference and a common commercial cigarette. It was shown that the analysis provides useful information regarding the amino acid level variation between tobacco types, between tobacco stalk positions, and between the growing locations of different tobaccos. [Beitr. Tabakforsch. Int. 26 (2015) 334-343]