The impact of e-cigarettes has been debated for years, offering both a cessation method for adult smokers and a gateway risk for adolescents who may not have otherwise been exposed to tobacco. Koop researchers looked at the current research on net population-level health benefits and harms. They found that the years of life saved for adult smokers does not outweigh the years of life that will be lost by adolescents beginning to smoke today. Read their article here and The Dartmouth's piece on it here.