ETS (environmental tobacco smoke) is composed or exhaled mainstream smoke (MS) from the smoker, sidestream smoke (SS) emitted from the smoldering tobacco between puffs and contaminants that diffuse through the cigarette paper and mouth between puffs. These emissions contain both vapor phase and particulate contaminants. ETS is a complex mix or over 4,000 compounds. This mix contains many Known or suspected human carcinogens and other toxic agents. More or these toxic compounds are round in SS than in MS. Workplace exposure to ETS can result in significant smoke intake, and passive smoke exposure may be related to impair respiratory function and an increase risk or lung cancer in nonsmokers. For nonsmokers sharing a work environment with cigarette smokers, the workplace must be considered hazardous independently or any specific industrial toxic exposure. The risk is particularly important when a high percentage or the workers smoke or where smokers and nonsmokers work in poorly ventilated areas. Nicotine is converted in the body to cotinine: cotinine therefore can be used as an indirect measure or a person's recent exposure to tobacco smoke. Levels or nicotine in hair and levels or cotinine in body fluids (saliva and urine) have been shown to increase with increasing environmental nicotine levels and with self-reported ETS exposure. The measurement or nicotine or cotinine in hair may be more appropriate for longer-term exposure to tobacco. The purpose or this study is to comparing airborne nicotine levels and hair cotinine level in restaurant workers. Concentration or airborne nicotine and hair nicotine (and cotinine) is closely related to exposed frequency or sidestream smoke in the workplace. Nicotine in hair is a better predictor or airborne nicotine than hair cotinine. Hair nicotine can be a useful tool to assess ETS exposure interventions. It may have limiting levels or ETS exposure by placing regulatory restrictions on smoking in workplaces and in public spaces.