Justice

The Reason Saliva Drug Testing Hasn't Caught On

July 18th 2016

By:
Kyle Jaeger

In a bid to combat rising rates of drugged driving, police departments in select counties throughout Michigan are set to launch a saliva-based drug testing program this year. But questions about the efficacy of these field tests — particularly when it comes to detecting marijuana — have delayed the program's rollout nationwide.

saliva test

Half of the states in the U.S. have legalized marijuana for either medical or recreation purposes, raising concerns about the ability of law enforcement to screen suspected drugged drivers. Though certain companies are attempting to develop marijuana breathalyzers, testing for active impairment has posed challenges. Now, law enforcement officials are starting to look into saliva testing as an alternative.

In the five Michigan counties selected for the one-year saliva testing pilot program, officers will conduct traditional sobriety tests first. If a suspect fails, officers will then administer a saliva test that's designed to detect marijuana and other drugs such as meth, cocaine, and opioids, CBS Detroit reports. The problem is, this test isn't particularly effective at detecting marijuana.

marijuana-joint

Paul Armentano, the deputy director of the National Organization for the Reform of Marijuana Laws (NORML), explains why oral saliva testing isn't effective for marijuana detection.

"By and large, the reason oral saliva testing wasn't ready for primetime years ago was because it wasn't particularly sensitive to picking up carboxy-THC [the metabolized form of THC that drug tests detect]," Armentano told ATTN:. "That shouldn't surprise anybody who knows anyone or has tried marijuana themselves. One of the immediate side effects of inhaling cannabis is dry mouth, so if you've got a product that is being used that tends to at least temporarily dry out the saliva glands, having a test that relies on collecting saliva it probably isn't going to be very effective."

Armentano described why saliva testing might present problems:

"That's the hurdle they can't overcome on this. It's not that if you had an adequate saliva sample that the technology isn't there to analyze it, it's getting that sample from people that have recently used marijuana. So when they do studies, they take people that have recently used marijuana, they give them saliva tests, and they come back negative. But they should be coming back positive. They just used the marijuana. That's the problem with oral fluid testing. If the focus was on some of these other drugs, they'd roll the test out anyway. But since it doesn't really work for marijuana, there's never been a really big rollout for that."

traffic stop

Concerns about the science behind these saliva testing instruments has led some to criticize the Michigan State Police's pilot program. Attorney Neil Rockind told mlive.com that the policy change would set "a dangerous precedent" for Michigan.

"The criminal justice system wants to take science and turn it into a fast, easy utility," Rockind said. "Science is neither fast nor easy."

RELATED: British Company Developing Field Sobriety Test for Marijuana