CLEARING UP CLOUDY OUI POT DETECTION

UMass teams lead research efforts

The first marijuana breath test could be ready for use by the end of the year, but researchers at the University of Massachusetts Medical School — now planning a massive study on the effects of pot use on drivers — say it could be years before cops will be able to get an accurate read on the level of impairment.

“Marijuana is so hard. It’s not like alcohol, where we have decades of experience and we have a legal level,” said Dr. Peter Chai of the medical toxicology team in the department of emergency medicine at UMass. “I think the device will work and we’ll be able to get a measurement, but the big question is: What does it mean both in the court of law and from a medical perspective?”

The recent legalization of pot in Massachusetts and a handful of other states has created a dilemma for police, who say they don’t have the tools or the laws to effectively deal with people driving while high. That’s spurred a tech race to develop a device that can help navigate the murky waters of monitoring and cracking down on impaired driving.

The new law has raised complex questions: The Massachusetts Supreme Judicial Court is now considering whether police can testify if someone is suspected to have been driving under the influence of marijuana. In one headline-grabbing case, a Gloucester driver who told police he had just smoked pot before he hit a school bus was not charged with OUI — when police said they couldn’t prove his level of impairment.

That’s the issue California startup Hound Labs Inc. aims to resolve with its pot breath-testing device, which company reps say likely will be available by the year’s end.

But researchers say the science simply isn’t there yet. Unlike alcohol, marijuana is broken down into many different compounds — many of which degrade quickly, making it hard to detect in the breath even if the person is still impaired.

“With alcohol, if you have a detectable level, it correlates very closely with impairment,” said UMass toxicology fellow Dr. Jeffrey Lai. “With marijuana, some of the problems are that the metabolism is a little more complicated, and the ability of various tests to pick up the various components that are psychoactive is more difficult.”

Several years worth of research went into developing the .08 per se impairment standard for alcohol. A similar standard is needed for marijuana, and it also will take time, Lai said.

Hound Labs reps say they hope to contribute to that initial data with their new device, company cofounder Jenny Lynn said.

“It would be one more piece of objective data at the roadside,” Lynn said. “Right now officers have no information about recent use.”

Lynn said the company won’t disclose the specific technology it uses, but the ultra-sensitive device measures pot levels in parts per trillion. Alcohol breath-test devices measure in parts per thousand.

But for now, the most reliable method of measurement is testing the blood for THC, which is what UMass toxicology and trauma teams will do to examine the correlation between marijuana levels and car accidents. The groups are now in the planning stages of the study.

“The serum THC concentration is the most accurate reflector we have now,” Lai said. “We need to be figuring out the correlation in the real world and going from there.”