This study is the first to measure tobacco-specific carcinogens in nonsmokers exposed to environmental tobacco smoke (ETS) in a public setting, in this case a casino. (A previous study by the University of Minnesota examined tobacco carcinogens in nonsmoking women who were exposed to secondhand smoke at home.)
"Environmental tobacco smoke in restaurants, bars, and casinos presents a potential health hazard to employees and non-smoking patrons," said lead author Kristin Anderson, Ph.D., associate professor in the School of Public Health and Cancer Center member. "However, further studies are needed to examine the long-term health effects, on employees and patrons, of transient exposure to ETS."
Biomarkers were measured in urine samples from nonsmokers before and after a four-hour visit to a casino where smoking is allowed. The researchers tested for NNK through its urinary metabolites, NNAL and NNAL-Gluc, which are excellent biomarkers of human uptake of NNK. NNAL, like NNK, is a potent pulmonary (lung) carcinogen in rodents and a probable human carcinogen. The study found that, on average, the levels of NNK metabolites were increased two-fold (112 percent), demonstrating that exposure of nonsmokers to ETS in a public setting results in uptake of a tobacco-specific lung carcinogen.
Co-author Stephen Hecht, Ph.D., Cancer Center member and professor of Laboratory Medicine and Pathology in the Medical School, previously identified the lung carcinogen, NNK, and its metabolites NNAL and NNAL-Gluc, as tobacco-specific compounds. "There are no known sources of NNAL and
Contact: Brenda Hudson
University of Minnesota