Vaping Is Risky. Why Is the F.D.A. Authorizing E-Cigarettes?

When they first appeared in the United States in the mid-2000s, “electronic nicotine delivery systems” — e-cigarettes, vapes, e-liquids and other wares that contain the stimulant found in tobacco — were subject to little federal oversight. Their makers could incorporate countless other ingredients and flavorings. Like cigarettes before them, the devices proved extremely attractive to…