Aspects of the design protocol and the statistical methods for analysis of tar, nicotine and carbon monoxide yields in cigarette smoke that can affect the measurement variability within collaborative studies (original) (raw)
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Beiträge zur Tabakforschung / Contributions to Tobacco Research, 2014
Yields of selected mainstream smoke analytes expressed per milligram of nicotine yield (nicotine ratio) and ceilings on these ratios have been proposed by WHO as part of future cigarette product regulation. This paper describes the different approaches required for precision assessment, depending on whether yields or nicotine ratios are being studied. The widely used approach of assessment of yield precision is to perform a collaborative study using a standardised method. However, for assessment of ratio precision the measurement of smoke analyte and smoke nicotine yields are often not carried out on the same set of cigarettes (unpaired) due to analytical constraints and therefore the statistical approach described in ISO 5725 is inappropriate due to the various replicate combinations. In this paper, the precision of ratios was computed with unpaired measurements for NNN and nicotine yield data for the CM6 monitor test piece and the Kentucky Reference 1R5F cigarette carried out duri...
Comparison of Smoke Yield Data Collected from Different Laboratories
Beiträge zur Tabakforschung / Contributions to Tobacco Research, 2014
In the context of increasing tobacco product regulations, more requirements are observed for the reporting of smoke constituent yield data and its variability e.g., US Food and Drug Administration (FDA). The objective of this work was to evaluate the relevance of the short term standard deviation to describe the variability of measurements using the dataset of the CORESTA 2006 Joint Experiment which included a number of cigarette smoke constituents more recently identified by FDA for reporting. Their testing protocol required the analysis of Kentucky Reference cigarettes 2R4F and 1R5F performing five replicates run over consecutive days, repeated during three different time periods. This dataset provided access to different sources of smoke yield variability across measurements: short term and medium term within-laboratory variability and among-laboratory variability. For each reference cigarette, analysis of variance on one factor (laboratory) combined with the Newman-Keuls multipl...
Tobacco Control, 2004
Survey of nicotine, tar, and carbon monoxide (CO) smoke deliveries from 77 cigarette brands purchased in 35 countries was conducted using a standardised machine smoking method. The goal of this study was to determine regional variations and differences in the tar, nicotine, and CO smoke yields of a cigarette brand manufactured by a leading transnational corporation and of non-US locally popular cigarette brands. Design: The majority of the cigarettes were purchased in each of the participating countries by delegate members of the World Health Organization and forwarded to the Centers for Disease Control and Prevention for analysis. Smoke deliveries were determined using a standardised smoking machine method and subsequent gravimetric and gas chromatography analysis. Results: The smoke deliveries varied widely. Mainstream smoke deliveries varied from 6.8 to 21.6 mg tar/ cigarette, 0.5 to 1.6 mg nicotine/cigarette, and 5.9 to 17.4 mg CO/cigarette. In addition to the smoke deliveries, the cigarettes were examined to determine physical parameters such as filter composition, length, and ventilation levels. Conclusion: Analysis of the smoke deliveries suggested that cigarettes from the Eastern Mediterranean, Southeast Asia, and Western Pacific WHO regions tended to have higher tar, nicotine, and CO smoke deliveries than did brands from the European, American, or African WHO regions surveyed.
International Journal of Environmental Research and Public Health, 2020
Human smoking behavior influences exposure to smoke toxicants and is important for risk assessment. In a prospective observational study, the smoking behavior of Marlboro smokers was measured for 36 h. Puff volume, duration, frequency, flow and inter-puff interval were recorded with the portable CReSSmicro™ device, as has often been done by other scientists. However, the use of the CReSSmicro™ device may lead to some registration pitfalls since the method of insertion of the cigarette may influence the data collection. Participants demonstrated consistent individual characteristic puffing behavior over the course of the day, enabling the creation of a personalized puffing profile. These puffing profiles were subsequently used as settings for smoking machine experiments and tar, nicotine and carbon monoxide (TNCO) emissions were generated. The application of human puffing profiles led to TNCO exposures more in the range of Health Canada Intense (HCI)-TNCO emissions than for those of ...
Multivariate Statistical Analysis of Cigarette Design Feature Influence on ISO TNCO Yields
Chemical Research in Toxicology, 2016
The aim of this study is to explore how differences in cigarette physical design parameters influence tar, nicotine, and carbon monoxide (TNCO) yields in mainstream smoke (MSS) using the International Organization of Standardization (ISO) smoking regimen. Standardized smoking methods were used to evaluate 50 U.S. domestic brand cigarettes and a reference cigarette representing a range of TNCO yields in MSS collected from linear smoking machines using a nonintense smoking regimen. Multivariate statistical methods were used to form clusters of cigarettes based on their ISO TNCO yields and then to explore the relationship between the ISO generated TNCO yields and the nine cigarette physical design parameters between and within each cluster simultaneously. The ISO generated TNCO yields in MSS are 1.1-17.0 mg tar/cigarette, 0.1-2.2 mg nicotine/cigarette, and 1.6-17.3 mg CO/cigarette. Cluster analysis divided the 51 cigarettes into five discrete clusters based on their ISO TNCO yields. No one physical parameter dominated across all clusters. Predicting ISO machine generated TNCO yields based on these nine physical design parameters is complex due to the correlation among and between the nine physical design parameters and TNCO yields. From these analyses, it is estimated that approximately 20% of the variability in the ISO generated TNCO yields comes from other parameters (e.g., filter material, filter type, inclusion of expanded or reconstituted tobacco, and tobacco blend composition, along with differences in tobacco leaf origin and stalk positions and added ingredients). A future article will examine the influence of these physical design parameters on TNCO yields under a Canadian Intense (CI) smoking regimen. Together, these papers will provide a more robust picture of the design features that contribute to TNCO exposure across the range of real world smoking patterns.
Regulatory Toxicology and Pharmacology, 2015
There is a drive toward the mandated lowering and reporting of selected toxicants in tobacco smoke. Several studies have quantified the mainstream cigarette emissions of toxicants, providing benchmark levels. Few, however, have examined how measured toxicant levels within a single product vary over time due to natural variation in the tobacco, manufacturing and measurement. In a single centre analysis, key toxicants were measured in the tobacco blend and smoke of 3R4F reference cigarette and three commercial products, each sampled monthly for 10 months. For most analytes, monthly variation was low (coefficient of variation <15%); but higher (P20%) for some compounds present at low (ppb) levels. Reporting toxicant emissions as a ratio to nicotine increased the monthly variation of the 9 analytes proposed for mandated lowering, by 1-2 percentage points. Variation in toxicant levels was generally 1.5-1.7-fold higher in commercial cigarettes compared with 3R4F over the 10-month period, but increased up to 3.5-fold for analytes measured at ppb level. The potential error (2CV) associated with single-point-intime sampling averaged $20%. Together, these data demonstrate that measurement of emissions from commercial cigarettes is associated with considerable variation for low-level toxicants. This variation would increase if the analyses were conducted in more than one laboratory.
International Journal of Environmental Research and Public Health, 2013
Although millions of people are using electronic cigarettes (ECs) and research on this topic has intensified in recent years, the pattern of EC use has not been systematically studied. Additionally, no comparative measure of exposure and nicotine delivery between EC and tobacco cigarette or nicotine replacement therapy (NRTs) has been established. This is important, especially in the context of the proposal for a new Tobacco Product Directive issued by the European Commission. A second generation EC device, consisting of a higher capacity battery and tank atomiser design compared to smaller cigarette-like batteries and cartomizers, and a 9 mg/mL nicotine-concentration liquid were used in this study. Eighty subjects were recruited; 45 experienced EC users and 35 smokers. EC users were video-recorded when using the device (ECIG group), while smokers were recorded when smoking (SM-S group) and when using the EC (SM-E group) in a randomized cross-over design. Puff, inhalation and exhalation duration were measured. Additionally, the amount of EC liquid consumed by experienced EC users was measured at 5 min (similar to the time needed to smoke one tobacco cigarette) and at 20 min (similar to the time needed for a nicotine inhaler to deliver 4 mg nicotine). Puff duration was significantly higher in ECIG (4.2 ± 0.7 s) compared to SM-S (2.1 ± 0.4 s) and SM-E (2.3 ± 0.5 s), while inhalation time was lower (1.3 ± 0.4, 2.1 ± 0.4 and 2.1 ± 0.4 respectively). No difference was observed in exhalation duration. EC users took 13 puffs and consumed 62 ± 16 mg liquid in 5 min; they took 43 puffs and consumed 219 ± 56 mg liquid in 20 min. Nicotine delivery was estimated at 0.46 ± 0.12 mg after 5 min and 1.63 ± 0.41 mg after 20 min of use. Therefore, 20.8 mg/mL and 23.8 mg/mL nicotine-containing liquids would deliver 1 mg of nicotine in 5 min and 4 mg nicotine in 20 min, respectively. Since the ISO method significantly underestimates nicotine delivery by tobacco cigarettes, it seems that liquids with even higher than 24 mg/mL nicotine concentration would be comparable to one tobacco cigarette. EC use topography is significantly different compared to smoking. Four-second puffs with 20-30 s interpuff interval should be used when assessing EC effects in laboratory experiments, provided that the equipment used does not get overheated. Based on the characteristics of the device used in this study, a 20 mg/mL nicotine concentration liquid would be needed in order to deliver nicotine at amounts similar to the maximum allowable content of one tobacco cigarette (as measured by the ISO 3308 method). The results of this study do not support the statement of the European Commission Tobacco Product Directive that liquids with nicotine concentration of 4 mg/mL are comparable to NRTs in the amount of nicotine delivered to the user.
Regulatory Toxicology and Pharmacology, 2011
In 2005, Human-Smoked (HS) tar and nicotine yields from commercial Canadian cigarettes were determined using a part filter analysis method to obtain estimates representative of human smoking behavior. In 2006, new cigarette designs were introduced to ensure compliance with the Canadian Low Ignition Propensity (LIP) regulations. It was not known how the changes in product design would affect HS yields. To assess the impact of the cigarette design modifications on HS yields, a further group of Canadian smokers was recruited for smoking the modified version of 10 products previously assessed. No differences in estimated HS tar yields were found between products following product modification. The HS nicotine yield was different for one product. In general, HS yields were higher than ISO machine yields while Canadian intense machine yields were more representative of the maximum HS yields. The same product ranking order was obtained for HS yields and the two machine yields but differences between the mean HS yields and ISO yields were smaller as the product ISO yields increased. Higher HS yields were measured when products were smoked by male smokers. The methodology used in this study showed the wide range of HS yields obtained by smokers as well as a good degree of stability in average HS yields just before and after the introduction of LIP regulations.