In states such as Washington and Colorado, the legalization of recreational marijuana use has brought a shadow market into the open.
If you’re into this sort of thing, it’s probably made you a lot less paranoid. But as more people legally smoke up, state and local law enforcement face a buzzkill: There’s no quick way to know if a driver is stoned.
That’s partly because the science of highs is sketchy.
A May study from the AAA Foundation for Traffic Safety concluded that there isn’t a reliable link between impairment and the level of THC, pot’s psychotropic agent, in a driver’s blood. Nonetheless, in Washington, as in many states, the legal limit is based on blood concentration. So officials are looking to a septuagenarian chemist to build a breathalyzer for weed. The chemist’s name, of course, is Herb.
Herb Hill, a professor at Washington State University, has spent more than four decades pioneering ways to detect chemicals—or, more accurately, to detect chemical signatures based on the movement of a substance’s component ions. His work helps various government and military inspectors swab laptops for explosives, sniff out mold-contaminated food, and find sarin gas on a battlefield. As he prepares to retire next year, Hill and his last graduate student, Jessica Tufariello, are applying his techniques to test for pot.
Today, if cops in Seattle suspect a driver has exceeded the legal limit (5 nanograms of THC per milliliter of blood), they must call for specially trained colleagues to run a 12-point test examining the suspect’s light sensitivity, eyelid tremors, balance, and other factors. Then they’ll need a search warrant to draw a sample of the suspect’s blood at a nearby hospital. The whole process can take hours, during which the drug could dissipate in the bloodstream. A breathalyzer could measure drug levels in the bloodstream or at least quickly determine whether a blood draw is warranted.
“It’s an interesting project to end on, and an important one,” Hill says, though he acknowledges the 5ng level he’s testing for is an unscientific legal guideline. “I haven’t seen anybody who has determined how that relates to being impaired.” He began thinking about building a breathalyzer for drugs in 2009 at the suggestion of his friend Nick Lovridge, a retired WSU political science professor who’d been doing research for the state on ways to reduce highway fatalities.
The chemistry professor was already planning for retirement, so he asked Tufariello for help. The pair originally planned to test for 10 common illicit substances but narrowed their focus to THC in 2012, after Washington voters approved a ballot measure legalizing pot. Hill says he’s secured about $300,000 in funding commitments from Chemring Group, a British defense contractor with U.S. divisions that produce detection devices for chemical and biological agents. In exchange, Chemring has exclusive rights to use his and Tufariello’s work to develop a commercial breathalyzer.
Read more of the original article in Bloomberg.