Development of a Method to Estimate Mouth-Level Benzo[a]pyrene Intake by Filter Analysis

Abstract

Background: Benzo[a]pyrene (BaP) is one of the most potent carcinogens generated in cigarette smoke. During smoking, cigarette filters trap a significant portion of mainstream smoke benzo [a]pyrene. This trapped portion is proportional to what exits the end of the filter and is drawn into the mouth of smokers.Methods: We developed a new method to estimate mouth-level BaP intake using filter analysis. In this analysis, cigarettes are smoked by a smoking machine using a variety of conditions to yield a range of mainstream smoke deliveries, which approximate a range of human puffing characteristics. Mainstream smoke BaP collected on Cambridge filter pads and the corresponding 1-cm mouth-end cigarette filter butts is extracted, purified by solid-phase extraction, and quantified by high-performance liquid chromatography coupled with a fluorescence detector. On the basis of the amount of BaP retained in cigarette butts and the amount collected on pads, we can relate them using a linear regression model.Results: Using this model and subsequently analyzing cigarette filters collected from smokers, we are able to estimate their mouth-level intakes, which smokers received when they consumed cigarettes. We made a series of measurements using research cigarettes and select commercial cigarettes having a wide range of machine smoke "tar" and nicotine deliveries.Conclusions: In all cases, results indicate a linear relation of BaP between cigarette filter butts and Cambridge filter pads, with R 2 ranging from 0.93 to 0.98.

Mouth-Level Intake of Benzo[a]pyrene from Reduced Nicotine Cigarettes

“…We previously developed and published a method involving chemical analysis of spent cigarette filter butts [7]. During smoking, cigarette filters trap a significant portion of mainstream smoke constituents, including BaP.…”

A longitudinal study of smokers’ exposure to cigarette smoke and the effects of spontaneous product switching

“…As the objective of the study was to investigate smokers in their own environment, nicotine equivalents and NNAL were chosen as the biomarkers of exposure as they are tobacco-specific and therefore not influenced by environmental and dietary sources (Hatsukami et al, 2006;Hecht, 2002). In addition, the use of the part-filter methodology has gained popularity recently and represents a non-invasive technique to provide estimates of MLE to nicotine and tar, in the subject's own environment (Clayton et al, 2010;Ding et al, 2012;Pauly et al, 2009;Polzin et al, 2009). Mendes et al (2008) aimed to address these concerns by inclusion of both a randomized, controlled, short-term phase and an unrestricted long-term follow-up phase in assessing the effects of forced switching.…”

Measurement of urinary Benzo[a]pyrene tetrols and their relationship to other polycyclic aromatic hydrocarbon metabolites and cotinine in humans

“…However, the relative proportion of B[ a ]P and pyrene differs from source to source (Dennis et al, 1991; Khalili et al, 1995; Lee et al, 2011), adding to the uncertainty in the estimated exposure of B[ a ]P when only based on 1-hydroxypyrene measurements. While B[ a ]P exposure from tobacco smoke can be estimated based on knowledge of the smoke intake and composition of the smoke (Ding et al, 2012), such estimates are associated with uncertainty because smoke chemistry varies across individual tobacco products and individual smokers’ puff frequencies and durations (St Charles et al, 2010). For these reasons, the use of specific B[ a ]P human exposure biomarkers may be preferable for exposure assessment, particularly when evaluating relative sources of exposure.…”