Development of a validation test for self-reported abstinence from smokeless tobacco products: preliminary results

Using X-ray fluorescence spectrometry, 11 heavy elements at concentrations that are easily detectable have been identified in smokeless tobacco products. These concentrations were found to increase in cheek epithelium samples of the user after exposure to smokeless tobacco. This feasibility study suggests that the level of strontium in the cheek epithelium could be a valid measure of recent smokeless tobacco use. It also demonstrates that strontium levels become undetectable within several days of smokeless tobacco cessation. This absence of strontium could validate a self-report of abstinence from smokeless tobacco. Finally, the X-ray spectrum of heavy metal content of cheek epithelium from smokeless tobacco users could itself provide a visual stimulus to further motivate the user to terminate the use of smokeless tobacco products.