• Research Review
• Journal Review

Authors: J Jensen, B Schillo, M Moilanen, B Lindgren, et al.

Reference: Cancer Epidemiol Biomarkers Prev 2010; 19(4): 1016-21
http://cebp.aacrjournals.org/content/19/4/1016.abstract

Reviewer: Joaquin Barnoya, MD, MPH, Contributing Editor, ProCor; Research Assistant, Professor of Surgery, Washington University in St. Louis, Missouri, USA; Director, Research and Education, Unidad de Cirugia Cardiovascular de Guatemala, Guatemala

Reviewer comments: Even though we have posted several studies showing significant decrease in secondhand smoke (SHS) exposure after smoking bans, this new study adds to the literature as it yields additional evidence on a tobacco specific carcinogen also decreased after a smoking ban. Further research is needed to evaluate if components of tobacco smoke (e.g. acrolein, cadmium) that lead to oxidative stress and endothelial dysfunction also decrease after a smoking ban.

Purpose of study: Minnesota enacted a comprehensive smoking ban on 1 October 2007. This study aims to determine employee exposure to nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNAL) a potent tobacco-specific lung carcinogen found in tobacco smoke.

Location of study: United States

Study design: Nonsmokers (and not using any nicotine product) who worked in bars, restaurants, or bowling alleys before and after the smoking ban where included in this study. Subjects were also required to live in a nonsmoking household to be included in the study. Subjects completed a Demographics and Smoke Exposure Environment form with questions about exposure to SHS at work, home, and when socializing. In addition, they were mailed an informed consent and a urine cup for sample collection that was to occur within the two weeks before the ban came into effect. The same methodology was repeated four to eight weeks after the law went into effect. NNAL and cotinine, adjusted for creatinine levels were measured. The difference of the log-transformed biomarkers before and after the ban is reported.

Results: Twenty-four subjects completed both questionnaires, signed the informed consent and provided urine samples in both parts of the study. They were on average age 26.9 years, worked 3.9 shifts per week and 6.9 hours per shift. Most (79%) workers showed at least a 50% reduction in total cotinine and 54% showed at least a 50% reduction in total NNAL. Mean difference before/after was 9.3 ng/mg of cotinine and 19.8 pmol/mg of NNAL (both adjusted for creantinine and statistically significant).