Exposure to and deposition of fine and ultrafine particles in smokers of menthol and nonmenthol cigarettes

Abstract

Introduction: Research on the deposition of mainstream smoke particulate in the respiratory tract of smokers is needed to understand how exposure may vary based on cigarette menthol content.

Methods: We conducted a nine-participant crossover study in which smokers were randomly assigned to cigarettes differing primarily in menthol content. Participants smoked the test cigarettes ad libitum for one week, provided spot urine samples, and then smoked four test cigarettes in a laboratory session; this was repeated for the other test cigarette in week two. Fine and ultrafine particulate matter in exhaled breath were characterized, and smoking behavior was monitored. Participant-specific mainstream smoke, generated using each participant’s topography data, was characterized. During home smoking, participants collected their spent test cigarette butts for estimates of mouth-level exposures (MLE) to mainstream nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK).

Results: Participant-specific mainstream smoke NNK was higher (39%) and daily MLE to NNK was also higher (52%) when participants smoked the menthol cigarette. Nicotine was not significantly different. Participants retained more ultrafine particulate (43%) and fine particulate benzo(a)pyrene (43%) when smoking the menthol cigarette. There were no significant differences in the levels of urinary biomarkers for nicotine, NNK, or pyrene.

Conclusion: This study demonstrates the use of noninvasive real-time techniques to measure exposure differences between cigarettes differing primarily in menthol content. Differences between NNK exposure, ultrafine particle and benzo(a)pyrene deposition, and smoking behavior were observed. Additional research using these techniques with cigarettes that differ only in menthol content is required to unequivocally attribute the exposure differences to presence or absence of menthol.

Keywords::

• Menthol
• nonmenthol
• fine particles
• ultrafine particles
• particulate
• 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone
• NNK
• benzo(a)pyrene
• BaP
• mouth level exposure
• MLE
• nicotine
• cotinine
• postpuff inhalation
• topography
• 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanol
• NNAL
• 1-hydroxypyrene
• electrical low pressure impactor
• SPA-D

Acknowledgments

The authors would like to thank Dr. John T. Bernert, Jr. and Dr. Yang Xia of the CDC for undertaking the analysis of the urine samples collected from the participants for the tobacco-specific nitrosamine metabolite, NNAL.

Dr. Richter was employed by the CDC when this study was designed and conducted. She is now employed by the FDA.

Declaration of interest

The information in this document has been funded wholly or in part by the Centers for Disease Control and Prevention (CDC) under Contract HHS-P23320045006XI to Battelle Memorial Institute. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of CDC. Mention of trade names or commercial products is for informational purposes only and does not constitute endorsement or recommendation for use by the US Government, the US Department of Health and Human Services, or CDC.