More young people are landing in U.S. emergency rooms with problems from synthetic marijuana use, a new study shows. The American Association of Poison Control Centers received 4,500 calls involving problems from synthetic marijuana from 2010 to 2011. Synthetic marijuana is sold under names such as K2, Spice, Blaze, Bliss and TranQuility. Read more here.

To read the Star Tribune's series on synthetic drugs, go to startribune.com/lethaldose.