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

Influence of HAC loading on yields of volatile toxicants from cigarettes of 17–24.6 mm circumference.
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Fig6: Influence of HAC loading on yields of volatile toxicants from cigarettes of 17–24.6 mm circumference.

Mentions: Mainstream cigarette smoke yields were measured from cigarettes with different HAC loadings (Table 4, and Figure 6). The analytes examined were volatile species that are commonly examined in studies of cigarette filter carbons (Branton et al.2011a). The HCI-VO tar yields of these cigarettes were matched to within 1 mg (~7%) for each circumference set; however, the data showed that the tar yields of the 24.6- and 21-mm circumference cigarettes decreased systematically as the HAC loading was increased, whereas the tar yield for the two 17-mm circumference cigarettes increased. The differences in tar yields were not large, but their systematic changes should be taken into account in the analysis of toxicant yields. CO and NO were also measured to evaluate the impact of the changed paper specification and levels of split-tipping ventilation in these designs. The data presented above for the split-tipping cigarettes suggested that no significant impact on volatile yields would be expected for the 7-mg ISO tar cigarettes designed for this study; this expectation was confirmed by the measured CO and NO yields, indicating that the experimental design is suitable for the assessment of HAC loading on volatile yields.Table 4


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)

Influence of HAC loading on yields of volatile toxicants from cigarettes of 17–24.6 mm circumference.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Fig6: Influence of HAC loading on yields of volatile toxicants from cigarettes of 17–24.6 mm circumference.
Mentions: Mainstream cigarette smoke yields were measured from cigarettes with different HAC loadings (Table 4, and Figure 6). The analytes examined were volatile species that are commonly examined in studies of cigarette filter carbons (Branton et al.2011a). The HCI-VO tar yields of these cigarettes were matched to within 1 mg (~7%) for each circumference set; however, the data showed that the tar yields of the 24.6- and 21-mm circumference cigarettes decreased systematically as the HAC loading was increased, whereas the tar yield for the two 17-mm circumference cigarettes increased. The differences in tar yields were not large, but their systematic changes should be taken into account in the analysis of toxicant yields. CO and NO were also measured to evaluate the impact of the changed paper specification and levels of split-tipping ventilation in these designs. The data presented above for the split-tipping cigarettes suggested that no significant impact on volatile yields would be expected for the 7-mg ISO tar cigarettes designed for this study; this expectation was confirmed by the measured CO and NO yields, indicating that the experimental design is suitable for the assessment of HAC loading on volatile yields.Table 4

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