Opponents of marijuana legalization return to one particular number over and over in their arguments: the number of emergency room visits involving marijuana, Washington Post reports. This ONDCP fact sheet breathlessly reports that "mentions of marijuana use in emergency room visits have risen 176 percent since 1994, surpassing those of heroin." The Drug Enforcement Administration's "Dangers and Consequences of Marijuana Abuse," a 41-page tour-de-force of decontextualized factoids, reports that marijuana was involved in nearly half a million E.R. visits in 2011, second only to cocaine.
The problem, of course, is that these numbers are meaningless without knowing how many people are using those drugs to start with. When you consider that there are approximately 70 times more marijuana users than heroin users in the United States, it makes sense that more of the former are going to the hospital than the latter, according to the Washington Post.