Cannabis plants grow in the greenhouse at Vireo Health’s medical marijuana cultivation facility, August 19, 2016 in Johnstown, New York. As eight states plus the District of Columbia have moved to fully legalize recreational marijuana, debates on the merits of legalization have focused on the effects of marijuana use on individuals and society: is marijuana bad for your lungs, or for your brain? Does it have therapeutic applications? Is it safer than alcohol or tobacco? Marijuana is one of the most studied substances in scientific literature, but the answers are scattered across tens of thousands of scientific papers.