Biomarker measurements in smokeless tobacco users indicate higher levels of nicotine exposure and cancer-causing tobacco-specific nitrosamines (TSNAs) than cigarette smokers, according to a study by government researchers.

Food and Drug Administration (FDA) and Centers for Disease Control and Prevention (CDC) researchers said data from 23,684 participants in the National Health and Nutrition Examination Survey from 1999 to 2012 show the higher levels as measured by cotinine and NNAL (a TSNA derivative) biomarker concentrations. “These patterns in NNAL levels for smokeless tobacco users may be changing over time,” states a study abstract in the publication Cancer Epidemiology Biomarkers & Prevention. The study can be found at: http://cebp.aacrjournals.org/content/early/recent