Carcinogen and Toxicant Exposure Among Young Adults Who Co-Use Cigarettes, E-cigarettes and Cannabis (Co-Tox Study)

Inclusion Criteria:

* Young adult (18-25 years old).
* Ability to read and write in English.
* Participants must fall into one of the following groups (based on self-report):
* Predominant e-cigarette consumer: defined as using nicotine-containing e-cigarettes daily for the past six months but not having used other nicotine containing products more than weekly or cannabis products for the past month.
* Predominant cannabis consumer: defined as using cannabis at least 3x/week for the past six months in any form, including smoking, vaping, and oral use, with no more than weekly use of any nicotine or tobacco products.
* E-cigarette-cannabis co-consumers: defined as daily use of nicotine e-cigarettes and use of cannabis at least 3x/week, including smoking, vaping, and oral use, for at least the past six months, with no use of other nicotine containing products more than weekly
* Predominant cigarette consumers: defined as using cigarettes at least daily for the past six months, but not have used other nicotine-containing products more than weekly or cannabis products for the past month
* Predominant cigarette-cannabis co-consumers: defined as those reporting daily cigarette use and use of cannabis at least 3x/week (including smoking or vaping) for at least the past six months, with no more than weekly use of other nicotine-containing products
* No self-reported diagnosis of kidney disease (current, or within the past year prior to the study visit).
* Participants must understand the voluntary nature of this study and sign a written informed consent form before proceeding with study activities.

Exclusion Criteria:

* Individuals under the age of 18 or over the age of 25.
* Currently pregnant or breastfeeding (female participants).
* Unwilling or unable to follow protocol requirements