Commissioners seek clarity on marijuana science
October 21, 2014
Hot Sulphur Springs — County officials are working to clear the haze of marijuana confusion before they tamp down their marijuana employee policy.
During their regular public meeting on Tuesday, Feb. 25, the board of county commissioners had Sarah Urfer of ChemaTox Laboratory, Inc. provide some clarification to the murkiness of marijuana use. She provided insight on best testing practices, how to determine impairment and how to develop policy.
Marijuana may now be legal for adults in Colorado, regulated similar to alcohol, but that's about where the similarities between the two substances end. County commissioners and staff all agree having workers stoned on the job is unacceptable, but proving an employee is high isn't as simple as a roadside test or blowing into a breathalyzer.
"It's not like alcohol, it doesn't eliminate the same way," Urfer told commissioners.
For drug testing, employers often use blood or urine testing to determine if tetrahydrocannbinol, or THC, was present in the body. THC is the psychoactive substance in cannabis plants that causes a person to get high. According to Urfer, THC will only remain in a person's system for around one to four hours, regardless of how much marijuana was ingested.
But THC also leaves behind a telling metabolite as the body processes it. Although both urine and blood testing are commonly used to find the metabolite, Urfer has a strong preference on which type of test she prefers.
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"Blood, blood, blood," she told commissioners. "I don't want to ever see another urine sample as long as I live."
That's because urine samples only indicate use within the last 1 to 4 weeks. With blood, tests can usually determine if a person was high within the last 24 hours.
County staff also brought up concerns about prolonged marijuana use affecting employees' productivity levels, even if they're never high at work. Urfer explained these concerns aren't unfounded. As THC moves through the body, its metabolites bind to the brain.
For marijuana chronic users, this can lead to a tolerance of some of the drug's side effects, like memory loss and the munchies, but "unfortunately, that (also) means they have a chronic central nervous system depressant in the body, which slows them down," Urfer said. "It can cause depression, slow reaction time (and) issues with perception."
For adults, however, these effects are reversible within one to six months once a person stops consuming marijuana. But Urfer stressed that in children under 18, marijuana causes permanent brain damage.
The nuances surrounding marijuana use have baffled lawmakers in other areas as well. Urfer was a key source for the Colorado state legislature as state officials drafted up new DUI regulations. Legislators finally settled on a limit of 5 nanograms of THC per milliliter of blood as the legal limit in determining if a driver is impaired. Urfer took issue with that level however, explaining to Grand County commissioners that impairment for most people starts at 1 nanogram per milliliter.
"There was some serious confusion in the legislature about the (scientific) literature," she explained.
Urfer said that in her opinion, lawmakers ultimately attempted to compromise by selecting a high number that's essentially made up and not based on sound science.
Beyond consulting policymakers, Urfer has had her plate full since her lab took over much of the state's blood-alcohol and blood-drug testing. Toxicology analysis at the Colorado Department of Public Health and Environment was suspended last July, and terminated altogether in October, after public concerns over the accuracy of their testing. An independent lab later verified the state's testing integrity, but CDPHE officials decided not to resume testing at the state lab. They found private labs like ChemaTox had done an adequate job handling the state's testing needs, at more competitive prices.
With all her expertise, Urfer's ultimate recommendation for the county's marijuana employee policy was simple – zero tolerance.
"Because of the complications we just talked about … it has always been my recommendation to people concerned about impairment on the job that they just not allow marijuana, period, to avoid any argument later," Urfer said.
Commissioners are taking Urfer's insight into consideration, but have yet to adopt any formal policy.
Leia Larsen can be reached at 970-887-3334 ext. 19603.