Visitors to Tennessee Department of Health facilities across the state including Manchester and Tullahoma will see a prominently-displayed public health advisory on electronic cigarettes and other electronic nicotine delivery systems. The advisory, originally posted to the TDH website earlier this year, cautions about using the devices or being exposed to secondhand emissions. Electronic cigarettes may emit a variety of chemicals. Most of these emissions have nicotine as a base ingredient, a highly addictive substance that can raise heart rate and blood pressure and damage coronary arteries. Currently there is no government regulation of how much nicotine, or any other unknown chemicals, a manufacturer may put in each electronic cigarette. A growing number of countries have either banned or restricted their use due to possible health risks both for users and for those exposed to second-hand emissions. Since TDH issued the advisory in February, the U.S. Food and Drug Administration has proposed rules calling for regulation of electronic nicotine devices, including health warnings similar to those required for conventional tobacco cigarettes.