Secondhand Vape Exposure: Effects, Who's at Risk, and More Just How Harmful Is Vaping? More Evidence Is Emerging. The New York Times Can Smoking and Vaping Cause Back Pain? National Spine Health Foundation The safest vape is the one you never start. Flavoured vapes were designed to feel harmless: Candy taste. Fruit smell. Cool packaging. Viral aesthetics. But your lungs don't care about the flavour.