Psychometric properties of measures for electronic cigarette dependence among former smoking electronic cigarette users ScienceDirect Disposable ecigs expose users to much higher levels of toxic metals than earlier generations of ecigs or cigarettes Stanton Glantz blog Understanding tobacco and e cigarette use among university students: a cross sectional study exploring nicotine dependence, quit intentions, and awareness of cessation support services BMC Public Health Springer Nature Link The impact of e cigarette exposure on different organ systems: A review of recent evidence and future perspectives ScienceDirect