CHICAGO (WBBM NEWSRADIO) — Questions remains about how to deal with drivers who are high on marijuana after recreational use of pot becomes legal in Illinois in January.
A sponsor of the recreational marijuana legislation, North Side State Senator Heather Stains, said at the bill signing earlier this week that there are ways to check drivers for excessive levels of THC, the active ingredient in marijuana.
„Right now there are swab tests available in the state of Michigan. Police have done a yearlong pilot in five counties and showed that there are roadside testing of swabs that are available,” she said.
Margeaux Bruner is a member of a state commission in Michigan that looked at ways to test drivers suspected of driving high. She told our sister station WWJ in Detroit there’s a problem with testing for THC.
„If you were to consume and then were to take a drug test a week or two or three weeks later, you would still show the presence of THC in your body, although you would not be impared,” Bruner said.
The Michigan commission determined police should rely on field sobriety tests, such as walking a straight line or counting backwards, to determine if a driver is impaired by marijuana.
As for why, the Michigan report states that unlike with alcohol, levels of tetrahydrocannabinol (THC) in a person’s blood are not a „reliable indicator” of whether they’re impaired.
„With alcohol there’s a .08 (BAC) limit, and if you are .08 you are considered impaired,” Bruner told WWJ. „Now, two people, it might take them a different amount of consumption to reach that .08; but we agree that once you reach that .08 you are compromised.
„It is not the same at all with THC, because it’s stored in the fat and not the blood. So a person with a higher metabolism would excrete it from the body much more quickly than a person with a slower metabolism.”
How the marijuana was consumed is also factor, she said, in how soon the effects from the pot dissipate.
„With alcohol, pretty much we’re all drinking it in liquid form,” Bruner said. „If you’re talking about THC, you can smoke it, you can vape it, you can eat it, you can put it on your body as a topical; in which case it would not cross the bloodstream and impair you at all.
„It also varies based on how much you consume, how habitually you consume. There are so many variations that make it completely different scientifically than alcohol. You’re not comparing apples and apples.”
Bruner said while other states with legalized recreational marijuana have set a THC limit, ranging from 1 to 5 nanograms (ng), „We decided to go in a different direction.”
Michigan approved medical marijuana use in 2008, and recreational marijuana use last year. Under the law, users can have up to 2.5 ounces (71 grams) of the drug on them and up to 10 ounces (284 grams) at home and grow up to 12 plants.