Rostron BL, et al. - Researchers assessed the links between cigarettes smoked per day (CPD) and biomarkers of exposure by analyzing data from Wave 1 of the Population Assessment of Tobacco and Health Study. Biomarker data by CPD were analyzed for over 2,700 adult daily cigarette smokers. By the number of cigarettes smoked, a dose-response association was shown by exposure to tobacco toxicants and constituents among daily smokers, but the link was not certainly linear in form. Compared with exclusive cigarette smokers, exposure to higher levels of certain toxicants and carcinogens was reported in dual users of cigarettes with either e-cigarettes or smokeless tobacco.