Rémi Julien - Academia.edu (original) (raw)
Papers by Rémi Julien
Regulatory toxicology and pharmacology, 2018
Since it was first required to measure and to report NFDPM and nicotine yields in a limited numbe... more Since it was first required to measure and to report NFDPM and nicotine yields in a limited number of countries, there has been an increasing trend for more testing and reporting requirements. Historically, the ISO 3308 smoking regime has been used to determine NFDPM and nicotine yields. However recommendations from the World Health Organization, now include the use of two smoking regimes such as the ISO 3308 and the WHO TobLabNet Official Method SOP01, the latter being considered as an intense smoking regime. Considering the increase in data produced and similarities between some smoke constituents formed during combustion, we explored possible correlations between emissions under intense and less intense smoking conditions. A set of 22 commercial cigarettes was tested. Eighty five smoke constituents were determined under both intense and less intense regimes. In addition 36 tobacco constituents, 14 cigarette design parameters and eight cigarette burning features were determined. A computational process was designed to implement multiple linear regression analyses enabling the identification of the best subsets of explanatory variables among emissions under intense conditions, cigarette design parameters, tobacco constituents and burning parameters. We succeeded in building simple linear models, involving four to six variables, while reaching satisfactory goodness of fit and R-squared values ranging from 0.87 to 1.00. Our findings suggest, in the range of products tested, that the additional data gained by using a second smoking regime does not necessarily increase the volume of information and consequently does not necessarily improve knowledge. This study supports the premise that the application of two smoking regimes does not produce a more comprehensive product characterisation compared to using one.
Beiträge zur Tabakforschung International/Contributions to Tobacco Research, 2017
Summary The burning of a cigarette is a series of consecutive sequences of both passive and activ... more Summary The burning of a cigarette is a series of consecutive sequences of both passive and active burnings when a smoking cycle is applied to the cigarette. A previous study, using a smoking machine, showed that cigarette nicotine yields are dependent linearly on the difference between the time of smouldering (passive burning) and the time of smoking (active burning). It is predicted that the smoker’s nicotine yield increases when the intensity of smoking increases, i.e., when the time to smoke a cigarette (smoking time) decreases. Note that observations made on machines might not be comparable to human behaviours. The aim of this study was to determine whether nicotine mouth-level exposure could be predicted through measurement of human smoking time. A smoking behaviour study was conducted to compare human smoking nicotine yields obtained from both filter tip analysis and the cigarette burning time model. Results showed that smokers’ exposure to the smoke depends essentially on th...
In order to apply this method, a new apparatus has been developed. This is constituted of a propo... more In order to apply this method, a new apparatus has been developed. This is constituted of a proportional commanded electromagnet linked to a strength sensor allowing a step force application on the product, and a displacement sensor for the recording of the product deformation. Then, a specific algorithm allows the deformation analysis for a full mechanical characterization of the product to test.
Nicotine & Tobacco Research
Introduction There are fundamental differences between electronic cigarettes (e-cigarettes) and c... more Introduction There are fundamental differences between electronic cigarettes (e-cigarettes) and conventional cigarette product categories with regards to potential environmental exposures, notably that e-cigarettes do not contain tobacco or generate side-stream emissions. Here we assess the spatial and temporal patterns of exhaled e-cigarette aerosol at a bystander’s position, and compare it with conventional cigarette smoke emissions. Methods Smokers were asked to use e-cigarettes or smoke conventional cigarettes in a room-simulating chamber. Volunteers used the products at different distances from a heated mannequin, representing a bystander, and under different room ventilation rates. Aerosol particle concentrations and size distributions at the bystander’s position were measured. Results For both product categories, the particle concentrations registered following each puff were in the same order of magnitude. However, for e-cigarettes the particle concentration returned rapidly...
Beitrage zur Tabakforschung International/ Contributions to Tobacco Research
Many tobacco product regulations worldwide require the reporting of ?tar”, nicotine and carbon mo... more Many tobacco product regulations worldwide require the reporting of ?tar”, nicotine and carbon monoxide and set limits on their yields measured following the ISO smoking regime. Within the current regulatory framework, the introduction or recommendation for an additional more intense smoking regime with filter ventilation blocked has been made. The relationship was evaluated between measured yields and the difference between smouldering and smoking times with filter ventilation open or blocked under different smoking regimes. Development and evaluation of a cigarette burning model revealed a straight line relationship passing through the origin, showing that the "tar", nicotine and CO yields from one smoking regime can be used to predict the yields at any smoking time. Consequently, the rationale for conducting laboratory work under an additional specific regime is questionable and the additional data set adds no more value beyond adding a point to a known line.
The behavior of a cigarette, during a puff, is strongly determined by the airflow distribution in... more The behavior of a cigarette, during a puff, is strongly determined by the airflow distribution inside. In order to better understand this behavior, a theoretical model has been used which is able to predict the pressure drop as well as the paper and tipping paper ventilation. This model needs to take into account several parameters which influence the flow rate and the pressure drop : cigarette and filter size, paper permeability, coefficients related to the laminar or turbulent airflow within the tobacco rod, the filter and the tipping paper. Whereas the cigarette sizes can be easily measured, the determination of the other parameters related to the airflow behavior is quite more difficult. In order to make this characterization easier, a permeability-meter commonly used for the paper permeability measurement has been modified. These modifications allow to carry out a quick and easy measurement of the pressure drop versus the flow rate within tobacco rods, filters and tipping paper...
Regulatory toxicology and pharmacology, 2018
Since it was first required to measure and to report NFDPM and nicotine yields in a limited numbe... more Since it was first required to measure and to report NFDPM and nicotine yields in a limited number of countries, there has been an increasing trend for more testing and reporting requirements. Historically, the ISO 3308 smoking regime has been used to determine NFDPM and nicotine yields. However recommendations from the World Health Organization, now include the use of two smoking regimes such as the ISO 3308 and the WHO TobLabNet Official Method SOP01, the latter being considered as an intense smoking regime. Considering the increase in data produced and similarities between some smoke constituents formed during combustion, we explored possible correlations between emissions under intense and less intense smoking conditions. A set of 22 commercial cigarettes was tested. Eighty five smoke constituents were determined under both intense and less intense regimes. In addition 36 tobacco constituents, 14 cigarette design parameters and eight cigarette burning features were determined. A computational process was designed to implement multiple linear regression analyses enabling the identification of the best subsets of explanatory variables among emissions under intense conditions, cigarette design parameters, tobacco constituents and burning parameters. We succeeded in building simple linear models, involving four to six variables, while reaching satisfactory goodness of fit and R-squared values ranging from 0.87 to 1.00. Our findings suggest, in the range of products tested, that the additional data gained by using a second smoking regime does not necessarily increase the volume of information and consequently does not necessarily improve knowledge. This study supports the premise that the application of two smoking regimes does not produce a more comprehensive product characterisation compared to using one.
Beiträge zur Tabakforschung International/Contributions to Tobacco Research, 2017
Summary The burning of a cigarette is a series of consecutive sequences of both passive and activ... more Summary The burning of a cigarette is a series of consecutive sequences of both passive and active burnings when a smoking cycle is applied to the cigarette. A previous study, using a smoking machine, showed that cigarette nicotine yields are dependent linearly on the difference between the time of smouldering (passive burning) and the time of smoking (active burning). It is predicted that the smoker’s nicotine yield increases when the intensity of smoking increases, i.e., when the time to smoke a cigarette (smoking time) decreases. Note that observations made on machines might not be comparable to human behaviours. The aim of this study was to determine whether nicotine mouth-level exposure could be predicted through measurement of human smoking time. A smoking behaviour study was conducted to compare human smoking nicotine yields obtained from both filter tip analysis and the cigarette burning time model. Results showed that smokers’ exposure to the smoke depends essentially on th...
In order to apply this method, a new apparatus has been developed. This is constituted of a propo... more In order to apply this method, a new apparatus has been developed. This is constituted of a proportional commanded electromagnet linked to a strength sensor allowing a step force application on the product, and a displacement sensor for the recording of the product deformation. Then, a specific algorithm allows the deformation analysis for a full mechanical characterization of the product to test.
Nicotine & Tobacco Research
Introduction There are fundamental differences between electronic cigarettes (e-cigarettes) and c... more Introduction There are fundamental differences between electronic cigarettes (e-cigarettes) and conventional cigarette product categories with regards to potential environmental exposures, notably that e-cigarettes do not contain tobacco or generate side-stream emissions. Here we assess the spatial and temporal patterns of exhaled e-cigarette aerosol at a bystander’s position, and compare it with conventional cigarette smoke emissions. Methods Smokers were asked to use e-cigarettes or smoke conventional cigarettes in a room-simulating chamber. Volunteers used the products at different distances from a heated mannequin, representing a bystander, and under different room ventilation rates. Aerosol particle concentrations and size distributions at the bystander’s position were measured. Results For both product categories, the particle concentrations registered following each puff were in the same order of magnitude. However, for e-cigarettes the particle concentration returned rapidly...
Beitrage zur Tabakforschung International/ Contributions to Tobacco Research
Many tobacco product regulations worldwide require the reporting of ?tar”, nicotine and carbon mo... more Many tobacco product regulations worldwide require the reporting of ?tar”, nicotine and carbon monoxide and set limits on their yields measured following the ISO smoking regime. Within the current regulatory framework, the introduction or recommendation for an additional more intense smoking regime with filter ventilation blocked has been made. The relationship was evaluated between measured yields and the difference between smouldering and smoking times with filter ventilation open or blocked under different smoking regimes. Development and evaluation of a cigarette burning model revealed a straight line relationship passing through the origin, showing that the "tar", nicotine and CO yields from one smoking regime can be used to predict the yields at any smoking time. Consequently, the rationale for conducting laboratory work under an additional specific regime is questionable and the additional data set adds no more value beyond adding a point to a known line.
The behavior of a cigarette, during a puff, is strongly determined by the airflow distribution in... more The behavior of a cigarette, during a puff, is strongly determined by the airflow distribution inside. In order to better understand this behavior, a theoretical model has been used which is able to predict the pressure drop as well as the paper and tipping paper ventilation. This model needs to take into account several parameters which influence the flow rate and the pressure drop : cigarette and filter size, paper permeability, coefficients related to the laminar or turbulent airflow within the tobacco rod, the filter and the tipping paper. Whereas the cigarette sizes can be easily measured, the determination of the other parameters related to the airflow behavior is quite more difficult. In order to make this characterization easier, a permeability-meter commonly used for the paper permeability measurement has been modified. These modifications allow to carry out a quick and easy measurement of the pressure drop versus the flow rate within tobacco rods, filters and tipping paper...