Changes in Cigarettes per Day and Biomarkers of Exposure Among US Adult Smokers in the Population Assessment of Tobacco and Health Study Waves 1 and 2 (2013-2015).March 30, 2020March 30, 2020https://www.ncbi.nlm.nih.gov/pubmed/32221599Leave a Reply Cancel replyYour email address will not be published. Required fields are marked *Name * Email * Website Comment * Save my name, email, and website in this browser for the next time I comment. ΔThis site uses Akismet to reduce spam. Learn how your comment data is processed.