Introduction:
Recently, in Germany, the use of electronic nicotine delivery systems (ENDS) increased, also among adolescents, and threatens to compromise tobacco control efforts. Regulation of e-cigarettes to protect public health has to be based on scientific evidence. Therefore, political decision makers, public health advocates as well as journalists need sound, but easily understandable scientific information.

Material and Methods:
Comprehensive, non-systematic review of recent studies on health effects and addictive potential of e-cigarettes. Translation of scientific evidence into easily understandable language and compilation into a report for political decision makers as well as the general public.

Results:
An easily understandable and highly illustrative report on the health effects of ENDS use has been compiled. E-cigarette aerosol contains, besides nicotine, particulate matter, carcinogens, heavy metals (i.e., lead) and volatile organic compounds (VOCs). Some of the toxicants can cause inflammation, oxidative stress or DNA damage. E-cigarette aerosol might increase the risk for several diseases affecting the cardiovascular and respiratory system. The production of toxicants in e-cigarette aerosol is influenced by several factors, including e-liquid components, nicotine concentration, and device factors such as power and device materials. E-cigarette use among adolescents and young adults is particularly alarming, as nicotine exposure during adolescence can harm brain development, cause nicotine addiction and can increase the probability of smoking initiation. Furthermore, exposure to second hand aerosol from e-cigarettes might be harmful to vulnerable bystanders. Further studies are needed on the long-term effects on human health by ENDS use.

Conclusions:
E-cigarettes are by no means harmless life-style products. ENDS use is addictive and may pose a health risk, especially for adolescents, pregnant women and non-smokers. The review communicates the impact of e-cigarette aerosol on human health in a way that is easily understandable for a lay audience. It gives recommendations for strengthening the regulation of e-cigarettes to prevent youth and young adults from vaping initiation and nicotine addiction. Governments are strongly recommended to include e-cigarettes in smoke-free legislation to protect vulnerable groups from the potential harm of second hand aerosol exposure.