Dittrich David J, Fieblekorn Richard T, Bevan Michael J, Rushforth David, Murphy James J, Ashley Madeleine, McAdam Kevin G, Liu Chuan, Proctor Christopher J
British American Tobacco, Group Research & Development, Regents Park Road, Millbrook, Southampton SO15 8TL UK.
Springerplus. 2014 Jul 22;3:374. doi: 10.1186/2193-1801-3-374. eCollection 2014.
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.
吸烟通过频繁且长时间接触毒物会引发严重疾病。目前正在研发各种技术以减少吸烟者接触毒物，包括过滤吸附剂、烟草处理方法和替代品。本研究考察了对过滤嘴通风进行改良、改变卷烟圆周以及活性炭过滤嘴长度和装填量，以及这些特性在低毒物原型（RTP）卷烟中的组合，对卷烟烟雾中毒物产率的影响。研发了一种名为分流接装的空气稀释机制，其中过滤嘴接装中部的一条多孔纸条起到作用，可将在人类吸烟时遇到的高流速下有效过滤嘴通风的损失降至最低，并促进挥发性毒物的扩散损失。与传统过滤嘴通风卷烟相比，在高流速机器吸烟条件下，分流接装降低了焦油和挥发性烟雾成分的排放，对于ISO焦油产率为1毫克的产品尤为显著。此外，与使用传统过滤嘴通风卷烟的吸烟者相比，1毫克ISO焦油卷烟的吸烟者口腔水平接触（MLE）焦油和尼古丁的量有所减少。然而，对于ISO焦油水平较高的卷烟，MLE没有显著降低。较小的卷烟圆周降低了侧流毒物产率，并改变了主流烟雾化学成分的平衡，芳香胺和苯并[a]芘水平降低，但甲醛产率增加。较小圆周的卷烟挥发性毒物的主流产率也较低。含有更高水平高活性碳（HAC）的较长卷烟过滤嘴显示出机器吸烟时挥发性毒物产率降低：在较高HAC装填量下，某些挥发性毒物的去除率高达97%。在一款RTP卷烟中，分流接装与最佳过滤嘴长度和卷烟圆周相结合，与商业对照卷烟相比，在机器吸烟条件下，该RTP卷烟多种毒物的主流（高达约90%）和侧流（主要为20%-60%）烟雾产率显著降低。对于包含多种降低毒物技术的RTP卷烟，观察到主流和侧流烟雾毒物产率显著降低；这些观察结果值得在临床研究中进一步评估，在临床研究中可以使用接触和生理效应的生物标志物来测试与现实世界的相关性。
