More and better research is needed to answer the question of whether e-cigarettes have an overall positive or negative impact on public health, according to a new congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine. “E-cigarettes cannot be simply categorized as either beneficial or harmful,” said David Eaton, chair of the committee that wrote the report, and dean and vice provost of the Graduate School of the University of Washington, Seattle. “In some circumstances, such as their use by non-smoking adolescents and young adults, their adverse effects clearly warrant concern. In other cases, such as when adult smokers use them to quit smoking, they offer an opportunity to reduce smoking-related illness.”