Project Summary
Cigar smoking is associated with multiple negative health outcomes, including increased risks for various types of
cancer. Cigar use in the U.S. increased between 2000 and 2011 even as cigarette sales declined over the same
time period. Cigar use is common among minority youth and as a vehicle to administer cannabis. Within the
product class of cigars, cigarillos are the most commonly used in the U.S. and are associated with specific public
health concerns, including higher rates of use by young adults (ages 18–24) in contrast to older adults and
different patterns of co-use of multiple tobacco products. Thus, it is important to improve the understanding of
particular factors related to cigarillo use in order to inform cancer epidemiology.
In the proposed research, we will identify the chemical constituents of mainstream cigarillo smoke that are
different than those of mainstream cigarette smoke through non-targeted chemical analysis (i.e., the identification
of chemicals that are not specified prior to analyzing a given sample). The expected results are important for
epidemiological purposes in that they can reveal carcinogens in cigarillo smoke beyond those known to be
commonly associated with tobacco smoke in general, thus providing a better understanding of environmental
risk factors in epidemiological research. Furthermore, the identified compounds can be used in later research
projects to inform the development of biomarkers of exposure that can be used in individual or population base
sampling to estimate cigarillo exposure.
To achieve our research objective, we will employ two-dimensional gas chromatography–time-of-flight mass
spectrometry (GC×GC-TOFMS), an advanced analytical chemistry technique with powerful capabilities for non-targeted
chemical analysis. GC×GC-TOFMS will be used to collect non-targeted analytical chemistry data for both cigarillo
smoke and cigarette smoke. The data from the two product (sub)classes will be compared against one another, and
those signals that differentiate the product (sub)classes will be assessed using computational toxicology databases
(e.g., the Environmental Protection Agency CompTox Chemicals Dashboard) to determine which are most likely from
compounds that would present significant carcinogenicity concerns in cigarillo smoke. Additional analyses will then be
performed using authentic chemical standards to confirm the chemical identities and to quantify the amounts in both
cigarillo smoke and cigarette smoke.
The proposed innovative research is designed to identify and quantify specific chemical constituents (1) that differentiate
cigarillo smoke from cigarette smoke, and (2) that are potentially carcinogenic. The results will complement
epidemiological data regarding the impact to public health associated with cigarillo use. This investigation will thus
advance cancer research through expanding knowledge about cancer risks for those populations most affected by
cigarillo smoking.