People who use smokeless tobacco products are exposed to as much or more nicotine and NNK, a cancer-causing chemical in tobacco products, as cigarette smokers, according to a study by researchers with the Centers for Disease Control and the Food and Drug Administration.
Smokeless tobacco products such as chewing tobacco, snuff, dip, snus, and dissolvable tobacco are used by about 7% of adult American men, the study noted. But few studies have looked at nicotine levels in people who use these products.
The study found that people who use smokeless tobacco products exclusively have higher levels of exposure to nicotine and to carcinogenic products in tobacco than do people who smoke cigarettes exclusively.
For this study, the researchers evaluated information from more than 23,000 participants in the National Health and Nutrition Examination Survey between 1999 and 2012. Participants provided blood and urine samples and these were examined for markers used to measure nicotine and NNK. They found the level of cotinine, a marker for nicotine exposure, was 0.043 nanograms/milliliter in nonsmokers, around 180 nanograms/milliliter in smokeless tobacco users, around 131 nanograms/milliliter in cigarette users, and around 184 nanograms/milliliter in people who used both smokeless tobacco and cigarettes.
Levels of NNAL, which is a marker for NNK, were about 0.98 micrograms per liter in nonsmokers, compared to 583 micrograms per liter in smokeless tobacco users, about 218 micrograms per liter in cigarette users and about 430 micrograms per liter in people using both smokeless tobacco and cigarettes. It is not known why there are these variations in exposure between cigarette smokers and smokeless tobacco users, the study noted.
The researchers added that NNAL concentrations for smokeless tobacco users appear to have declined from 2007 to 2008, but that this is based on limited sample sizes.
Recently, the FDA approved the sale of eight new smokeless tobacco products, which are thought to be a less dangerous option for tobacco users.
The study was published in the journal Cancer Epidemiology, Biomarkers and Prevention.