Adolescents and pregnant women. Ofbecause the concentration thc in marijuana has tripled over the past few decades, the science suggests marijuana use carries more risk than ever. It is fundamentally different product, both in potency and methods of use than what existed several decades ago. Mark secretary a czar called it a dangerous drug in the warning comes as Legal Marijuana has grown into a 10 billion industry in the united states. Nearly two thirds of states have legalized it, mainly for medical uses. An increasing number of states are also allowing personal Recreational Use of marijuana. Global news 24 hours a day on air and at tictoc on twitter, powered by more than 2700 journalists and analysts in over 120 countries. I am mark crumpton. This is bloomberg. Live from bloomberg world headquarters, i am vonnie quinn. Amber welcome to bloomberg markets. Here are the top stories from around the world. A shift in the trade narrative is lifting stocks. Optimism that china and the u. S