The percentage of positive drug tests among American workers has increased for the first time in more than a decade and in Colorado and Washington, increases have hit double digits.

This rise is drug use is driven by marijuana and methamphetamine use according to a study released September 2014 by Quest Diagnostics, the world’s leading provider of diagnostic information services.

“After years of decline, the prevalence of positive workforce drug tests is increasing,’” said Dr. Barry Sample, director, science and technology, Quest Diagnostics. He cautioned employers to “be aware of the potential for positive drug use by their workers and the risk that represents for the health and safety of their employees and the public.”

In the safety-sensitive test group which includes CDL drivers, tests with marijuana positivity increased 5.6%. In overall testing of all employee groups, methamphetamine use is at an all-time high since 2007. In the U.S. general workforce, urine testing revealed a 10% increase in test positivity for meth use in 2013 over 2012.

Colorado and Washington
An analysis of urine drug test data for the combined U.S. workforce from the two states with recreational use laws, Colorado and Washington, showed marijuana positivity rates increased 20% and 23% respectively. In contrast, the test positivity increase in the general workforce in all 50 states was 5%.

Dr. Sample reminds employers that “It is important for people to remember that while some states have legalized marijuana, the federal government has not. Employers in all 50 states generally have the authority to restrict the recreational use of marijuana and impose sanctions, including termination, on employees with positive drug tests.”

Read more in this issue of Colorado Green NOW:
Is the cloud flooding your business with dangerous apps?
Would you be this customer service hero?
How to assess ash trees and detect Emerald Ash Borer
What do landscape companies and football teams have in common?