Clinical Research Directory

Inclusion Criteria: * Smokers: 1) self-reported regular current filtered little cigars, cigarillos, little cigars, or small cigars use for the past 3 months; regular use will be defined as \>=8 cigars smoked per month based on data showing median cigarillo use is 7.5 times per month and median FLC use is 14 times per month 59. We will attempt to bring in heavier users if feasible during recruitment; or 2) Cigarette smokers (\>=8d/month for at least 3 months) with either (i) co-use of filtered little cigars, cigarillos, little cigars, or small cigars (at least once in their lifetime) or (ii) answering "yes" to the question "If all cigarettes were taken off the market, would you consider switching to filtered little cigars?" * willing to abstain from all tobacco and nicotine for at least 12 hours prior to lab sessions * Willing to bring their own, preferred brand little cigars/ small cigars/ cigarillos/ filtered little cigars to smoke in the lab on the first study visit * capable of and willing to provide written informed consent * read and speak in English. Exclusion Criteria: * Self-reported significant current lung disease (e.g. asthma, COPD, cystic fibrosis, pulmonary fibrosis); exercise-induced asthma, seasonal allergies for which a patient takes inhalers are allowed * History of diagnosis or treatment for lung cancer * Self-reported serious or uncontrolled kidney disease, liver disease, metabolic disease (thyroid, diabetes) * History of cardiac event or distress within the past 3 months * Unstable or significant psychiatric conditions (past and stable conditions will be allowed) * Substance use disorders besides nicotine addiction * Regular use of other tobacco products besides cigarettes such as snuff, chewing tobacco, snus, e-cigarettes \>10d per month * Exclusive large or premium cigar users * Use of blunts every time or most of the time * Regular use of cannabis \>10d per month * Planning to quit in next 30 days or currently trying to quit or quit attempt in past 30 days * Pregnant, delivery in past 12 weeks, breastfeeding, or planning to get pregnant * Inability to perform tests or follow instructions during testing