Limits...
Approaches for the design of reduced toxicant emission cigarettes.

Dittrich DJ, Fieblekorn RT, Bevan MJ, Rushforth D, Murphy JJ, Ashley M, McAdam KG, Liu C, Proctor CJ - Springerplus (2014)

Bottom Line: This study examined the effect of modifications to filter ventilation, variations in cigarette circumference and active charcoal filter length and loading, as well as combinations of these features in a reduced-toxicant prototype (RTP) cigarette, on the yields of toxicants in cigarette smoke.For higher ISO tar level cigarettes, however, there were no significant reductions in MLE.Split-tipping was combined with optimal filter length and cigarette circumference in an RTP cigarette that gave significantly lower mainstream (up to ~90%) and sidestream (predominately 20%-60%) smoke yields of numerous toxicants as compared with a commercial comparator cigarette under machine-smoking conditions.

View Article: PubMed Central - PubMed

Affiliation: British American Tobacco, Group Research & Development, Regents Park Road, Millbrook, Southampton SO15 8TL UK.

ABSTRACT
Cigarette smoking causes serious diseases through frequent and prolonged exposure to toxicants. Technologies are being developed to reduce smokers' toxicant exposure, including filter adsorbents, tobacco treatments and substitutes. This study examined the effect of modifications to filter ventilation, variations in cigarette circumference and active charcoal filter length and loading, as well as combinations of these features in a reduced-toxicant prototype (RTP) cigarette, on the yields of toxicants in cigarette smoke. An air-dilution mechanism, called split-tipping, was developed in which a band of porous paper in the centre of the filter tipping functions to minimise the loss of effective filter ventilation that occurs at the high flow rates encountered during human-smoking, and to facilitate the diffusional loss of volatile toxicants. As compared with conventional filter ventilation cigarettes, split-tipping reduced tar and volatile smoke constituent emissions under high flow rate machine-smoking conditions, most notably for products with a 1-mg ISO tar yield. Furthermore, mouth level exposure (MLE) to tar and nicotine was reduced among smokers of 1-mg ISO tar cigarettes in comparison to smokers of cigarettes with traditional filter ventilation. For higher ISO tar level cigarettes, however, there were no significant reductions in MLE. Smaller cigarette circumferences reduced sidestream toxicant yields and modified the balance of mainstream smoke chemistry with reduced levels of aromatic amines and benzo[a]pyrene but increased yields of formaldehyde. Smaller circumference cigarettes also had lower mainstream yields of volatile toxicants. Longer cigarette filters containing increased levels of high-activity carbon (HAC) showed reduced machine-smoking yields of volatile toxicants: with up to 97% removal for some volatile toxicants at higher HAC loadings. Split-tipping was combined with optimal filter length and cigarette circumference in an RTP cigarette that gave significantly lower mainstream (up to ~90%) and sidestream (predominately 20%-60%) smoke yields of numerous toxicants as compared with a commercial comparator cigarette under machine-smoking conditions. Significantly lower mainstream and sidestream smoke toxicant yields were observed for an RTP cigarette comprising several toxicant reducing technologies; these observations warrant further evaluation in clinical studies where real-world relevance can be tested using biomarkers of exposure and physiological effect.

No MeSH data available.


Related in: MedlinePlus

Role of split-tipping in diminishing the impact of flow-rate on ventilation efficiency.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4125608&req=5

Fig2: Role of split-tipping in diminishing the impact of flow-rate on ventilation efficiency.

Mentions: The effectiveness of split-tipping in minimising the reduction in effective ventilation with increasing flow rate is shown in FigureĀ 2 for unlit cigarettes. Within each ISO tar level, the effective ventilation decreased as the flow rate increased for both cigarette types. As the flow rate increased, however, higher ventilation levels were measured for the split-tipping EC than for the OML control at all measured flow rates. The difference in effective ventilation increased with flow rate, and was also more significant under the higher ventilation conditions present in low ISO tar cigarettes. Thus, split-tipping reduced the ventilation dependency on flow rate in unlit ECs under laboratory conditions. These findings suggest that the split-tipping ventilation system might reduce toxicant exposure from cigarettes under human smoking conditions.Figure 2


Approaches for the design of reduced toxicant emission cigarettes.

Dittrich DJ, Fieblekorn RT, Bevan MJ, Rushforth D, Murphy JJ, Ashley M, McAdam KG, Liu C, Proctor CJ - Springerplus (2014)

Role of split-tipping in diminishing the impact of flow-rate on ventilation efficiency.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4125608&req=5

Fig2: Role of split-tipping in diminishing the impact of flow-rate on ventilation efficiency.
Mentions: The effectiveness of split-tipping in minimising the reduction in effective ventilation with increasing flow rate is shown in FigureĀ 2 for unlit cigarettes. Within each ISO tar level, the effective ventilation decreased as the flow rate increased for both cigarette types. As the flow rate increased, however, higher ventilation levels were measured for the split-tipping EC than for the OML control at all measured flow rates. The difference in effective ventilation increased with flow rate, and was also more significant under the higher ventilation conditions present in low ISO tar cigarettes. Thus, split-tipping reduced the ventilation dependency on flow rate in unlit ECs under laboratory conditions. These findings suggest that the split-tipping ventilation system might reduce toxicant exposure from cigarettes under human smoking conditions.Figure 2

Bottom Line: This study examined the effect of modifications to filter ventilation, variations in cigarette circumference and active charcoal filter length and loading, as well as combinations of these features in a reduced-toxicant prototype (RTP) cigarette, on the yields of toxicants in cigarette smoke.For higher ISO tar level cigarettes, however, there were no significant reductions in MLE.Split-tipping was combined with optimal filter length and cigarette circumference in an RTP cigarette that gave significantly lower mainstream (up to ~90%) and sidestream (predominately 20%-60%) smoke yields of numerous toxicants as compared with a commercial comparator cigarette under machine-smoking conditions.

View Article: PubMed Central - PubMed

Affiliation: British American Tobacco, Group Research & Development, Regents Park Road, Millbrook, Southampton SO15 8TL UK.

ABSTRACT
Cigarette smoking causes serious diseases through frequent and prolonged exposure to toxicants. Technologies are being developed to reduce smokers' toxicant exposure, including filter adsorbents, tobacco treatments and substitutes. This study examined the effect of modifications to filter ventilation, variations in cigarette circumference and active charcoal filter length and loading, as well as combinations of these features in a reduced-toxicant prototype (RTP) cigarette, on the yields of toxicants in cigarette smoke. An air-dilution mechanism, called split-tipping, was developed in which a band of porous paper in the centre of the filter tipping functions to minimise the loss of effective filter ventilation that occurs at the high flow rates encountered during human-smoking, and to facilitate the diffusional loss of volatile toxicants. As compared with conventional filter ventilation cigarettes, split-tipping reduced tar and volatile smoke constituent emissions under high flow rate machine-smoking conditions, most notably for products with a 1-mg ISO tar yield. Furthermore, mouth level exposure (MLE) to tar and nicotine was reduced among smokers of 1-mg ISO tar cigarettes in comparison to smokers of cigarettes with traditional filter ventilation. For higher ISO tar level cigarettes, however, there were no significant reductions in MLE. Smaller cigarette circumferences reduced sidestream toxicant yields and modified the balance of mainstream smoke chemistry with reduced levels of aromatic amines and benzo[a]pyrene but increased yields of formaldehyde. Smaller circumference cigarettes also had lower mainstream yields of volatile toxicants. Longer cigarette filters containing increased levels of high-activity carbon (HAC) showed reduced machine-smoking yields of volatile toxicants: with up to 97% removal for some volatile toxicants at higher HAC loadings. Split-tipping was combined with optimal filter length and cigarette circumference in an RTP cigarette that gave significantly lower mainstream (up to ~90%) and sidestream (predominately 20%-60%) smoke yields of numerous toxicants as compared with a commercial comparator cigarette under machine-smoking conditions. Significantly lower mainstream and sidestream smoke toxicant yields were observed for an RTP cigarette comprising several toxicant reducing technologies; these observations warrant further evaluation in clinical studies where real-world relevance can be tested using biomarkers of exposure and physiological effect.

No MeSH data available.


Related in: MedlinePlus