This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. African Americans are an admixed population with varying proportions of African, European, and Native American ancestry. We hypothesize that genetic ancestry co-varies with NNAL, (nicotine, 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanol), a tobacco-specific metabolite of nicotine that has been associated with lung cancer. To date, it has not been determined whether NNAL is associated with susceptibility to chronic obstructive pulmonary disease (COPD). For this pilot proposal, we will recruit African American smokers, measure NNAL levels and urinary cotinine. We will determine if higher African ancestry is associated with increased levels of tobacco carcinogen metabolites (cotinine and NNAL) with the following Specific Aims: (1) we will enroll a cohort of 200 African Americans smokers and measure urinary cotinine and NNAL (total, NNAL-gluc, NNAL-gluc/NNAL);(2) we will measure genetic ancestry among all study participants;and (3) we will determine if genetic ancestry co-varies with cotinine and NNAL levels.