World smoking rates decline, but e cigarette use raises fresh concerns WHO Over 100 million people worldwide use e cigarettes, says WHO SWI swissinfo.ch Single use e cigarettes: The environmental impact of disposable vapes: A growing threat to waste management WMW Charting Global Tobacco Use by Country and Sex What are e cigarettes and the controversies that surround them? On Medicine Vaping Global State of Tobacco Harm Reduction