Positive tests for pot have increased by about 20 percent in Colorado from 2012 to 2013, according to Quest Diagnostics, a company responsible for a huge number of work-related drug testing across the country.
But the director of the drug testing branch of Quest says it’s too early to draw any conclusions from the data, though it’s easy to draw a parallel between the increase in positive pot tests and the legalization limited amounts of pot to adults 21 and up. Sales of cannabis to adults didn’t start until January of 2014, so that would not factor into the data.