‘A lot of people still think e-cigarettes are not harmful,” U.S. Surgeon General Jerome Adams said last week. “But studies show that nicotine is, pound for pound, as addictive as heroin.” Dr. Adams, speaking to the Community Anti-Drug Coalitions of America, was making an appeal to fear, not science. Drug consumption is measured by the dosage, not the pound.
More fundamentally, the concept of “addictiveness” is so vague that it can easily be manipulated. There isn’t a single agreed-upon scientific definition. [...]