The School of Public Health and Health Systems is conducting a three week study to compare the short term effects of smoking vs. vaping. The primary objective of the study is to examine the extent to which vaping/e-cigarette use reduces exposure to toxic chemicals, compared to smoking. The study is recruiting participants 18 + who use both e-cigarettes and cigarettes. The study involves abstaining from certain products, 4 lab visits (downtown Toronto), expired breath and urine samples, and short online daily surveys. For more information please visit https://smokingstudyuw.wordpress.com/ or email firstname.lastname@example.org Remuneration may be up to $295 for participation in the study. All information is kept confidential. The study is funded through The Ontario Ministry of Health and Long-Term Care.