LOS ANGELES, March 30 (Xinhua) -- The rate of positive drug test results among America's workforce reached its highest rate last year since 2001, said a new study published on Wednesday.
The number was up more than 30 percent in the combined U.S. workforce from an all-time low in 2010-2012, according to the annual drug testing index by Quest Diagnostics, a leading provider of diagnostic information services in the United States.
