Machine-smoking studies of cigarette filter color to estimate tar yield by visual assessment and through the use of a colorimeter

A Low-Cost, High-Throughput Digital Image Analysis of Stain Patterns on Smoked Cigarette Filter Butts to Estimate Mainstream Smoke Exposure

Standard machine smoking protocols provide useful information for examining the impact of design parameters, such as filter ventilation, on mainstream smoke delivery. Unfortunately, their results do not accurately reflect human smoke exposure. Clinical research and topography devices in human studies yield insights into how products are used, but a clinical setting or smoking a cigarette attached to such a device may alter smoking behavior. To better understand smokers' use of filtered cigarette products in a more natural environment, we developed a low-cost, high-throughput approach to estimate mainstream cigarette smoke exposure on a per-cigarette basis. This approach uses an inexpensive flatbed scanner to scan smoked cigarette filter butts and custom software to analyze tar-staining patterns. Total luminosity, or optical staining density, of the scanned images provides quantitative information proportional to mainstream smoke-constituent deliveries on a cigarette-by-cigarette basis. Duplicate sample analysis using this new approach and our laboratory's gold-standard liquid chromatography/tandem mass spectrometry (LC/MS/MS) solanesol method yielded comparable results (+7% bias) from the analysis of 20 commercial cigarettes brands (menthol and nonmentholated). The brands varied in design parameters such as length, filter ventilation, and diameter. Plots correlating the luminosity to mainstream smoked-nicotine deliveries on a per-cigarette basis for these cigarette brands were linear (average R2 > 0.91 for nicotine and R2 > 0.83 for the tobacco-specific nitrosamine NNK), on a per-brand basis, with linearity ranging from 0.15 to 3.00 mg nicotine/cigarette. Analysis of spent cigarette filters allows exposures to be characterized on a per-cigarette basis or a "daily dose" via summing across results from all filter butts collected over a 24 h period. This scanner method has a 100-fold lower initial capital cost for equipment than the LC/MS/MS solanesol method and provides high-throughput results (~200 samples per day). Thus, this new method is useful for characterizing exposure related to filtered tobacco-product use.

Analysis of chemical deposits on tooth enamel exposed to total particulate matter from cigarette smoke and tobacco heating system 2.2 aerosol by novel GC-MS deconvolution procedures

Tobacco smoking contributes to tooth discoloration. Pigmented compounds in the smoke generated by combustion of tobacco can cause discoloration of dental hard tissues. However, aerosols from heated tobacco products cause less discoloration than cigarette smoke (CS) in vitro. The objective of the present study was to optimize a method for extracting the colored chemical compounds deposited on tooth enamel following exposure to total particulate matter (TPM) from CS or a heated tobacco product (Tobacco Heating System [THS] 2.2), analyze the extracts by gas chromatography coupled to time-of-flight mass spectrometry, and identify the key chemicals associated with tooth discoloration. Sixty bovine enamel blocks were exposed for 2 weeks to TPM from CS or THS 2.2 aerosol or to artificial saliva as a control. Brushing without toothpaste and color measurements were performed each week. Noticeable discoloration of enamel was observed following exposure to CS TPM. The discoloration following exposure to THS 2.2 aerosol TPM or artificial saliva was not distinguishable to the eye (ΔE < 3.3). Carbon disulfide was used to extract surface-deposited chemicals. Untargeted analyses were followed by partial least squares correlation against discoloration scores (R2 = 0.96). Eleven compounds had variable importance in projection scores greater than 2. Discriminant autocorrelation matrix calculation of their mass spectral information identified eight of the eleven compounds as terpenoids. None of the compounds were related to nicotine. Several of these compounds were also detected in THS 2.2 aerosol TPM-exposed enamel, but at lower levels, in line with our findings showing less discoloration. Compared with CS TPM exposure, THS 2.2 aerosol TPM exposure resulted in lower deposition of color-related compounds on enamel surface, consistent with minimal discoloration of dental enamel.

Survey of characteristics of exposure to mainstream cigarette smoke using discarded cigarette butts from Korean smokers

Evaluating the characteristics of exposure to mainstream cigarette smoke is an essential field in tobacco research because of the large risk burden among smokers. Detailed evaluation of the complex factors pertaining to the exposure of smokers to mainstream cigarette smoke was attempted by analysis of discarded cigarette butts. A total of 5475 samples of discarded cigarette butts was collected to investigate the exposure characteristics in relation to Korean smokers. The basic physico-chemical characteristics of cigarettes, including the filter length, filter type, menthol addition, and nicotine and tar content, were determined and the manufacturer and cigarette size were identified. The tobacco-burned percentage (TBP)) and tar staining were used as physical markers, and actual human exposure to cigarette smoke was determined using the part filter method. Multiple linear regression analyses and generalized ordinal logistic regression analysis were conducted to identify the relationship between the socio-demographic factors and the physico-chemical characteristics of the cigarettes themselves and the exposure characteristics. Significant associations were observed between the TBP and age group, occupational group, manufacturer, tar staining, ISO tar content, and filter length. Increased odds of smoking with a heavier tar stain among Korean smokers were associated with blue collar workers vs. other workers, manufacturer B vs. other manufacturers, recess filter vs. other filter types, ISO tar content, and TBP. Finally, significant associations between the log-transformed human-smoked tar and nicotine yields and occupational group, the TBP, tar staining, and physico-chemical properties of cigarettes were found and were used to propose models for predicting the actual exposure to tar and nicotine. The proposed models account for 60-61% and 47-49% of the variance of human exposure to tar and nicotine, respectively. This analysis of discarded cigarette butts revealed that various factors, including socio-demographic factors such as age group and occupational group, as well as the physico-chemical properties of cigarette products such as the filter type and length, cigarette size, ISO tar and nicotine content, and mentholation, affect the characteristics of exposure of Korean smokers to mainstream cigarette smoke.