麻豆约拍

San Francisco has become the first US city to ban sales of e-cigarettes until their health effects are clearer. But what's the point, if it's still legal to use e-cigarettes, and possible to buy alcohol, tobacco and even marijuana in the city? Ellen Huet, from Bloomberg in San Francisco, explains what lies behind the city's Board of Supervisors' decision.

Photo: Woman vaping using an e-cigarette Credit: Getty Images