The real problem with vaping

E-cigarette vaping has both public health benefits and risks. | Mauro Grigollo/Getty Images

Cigarettes are a public health nightmare: both highly addictive and highly dangerous. By the middle of the 20th century, nearly half of Americans were smokers, putting themselves at risk of lung cancer, emphysema, and other chronic and deadly health problems. And while smoking rates have fallen significantly over the decades, 29 million people in the US continue to light up because once you start, it can be hard to stop.