CU and NIST Collaborate to Detect Cannabis in Breath – BizWest
BOULDER – The University of Colorado Boulder has teamed up with the National Institute of Standards and Technology to develop a reliable breath testing device to detect cannabis use.
The Breakthalyzer was developed in 1954 and has been a reliable tool for police agencies as they enforce laws related to alcohol poisoning. Testing for cannabis poisoning has proven to be more challenging, the university said in a press release.
“In our experimental research, we found that in regular cannabis users, their breath about an hour after use didn’t look very different from a baseline measure on days they didn’t use at all,” said Cinnamon Bidwell, an assistant professor at Harvard Medical School. The Department of Psychology and Neuroscience at the University of Colorado Boulder said in a written statement. “This suggests that this will not be easy, and a lot of careful research will need to be done to get it right.”
A small “proof of concept” study, Published in Journal of Respiratory Researchrepresents the first step in a collaboration between the National Institute of Standards and Technology and CU Boulder to develop reliable, standardized industry protocols for detecting cannabis impairment by breath — or determining if that is possible at all.
NIST chemical engineers Tara Lovestead and Kavita Jeraj pioneered this research with $2 million from the US Department of Justice’s National Institute of Justice and collaborated with Bidwell, a leading cannabis researcher, to help carry it out. In September, NIST awarded CU Boulder $600,000 to help continue the research.
Private companies have already begun marketing cannabis breathalyzers to law enforcement agencies, but researchers on the CU project aren’t sure of their reliability.
“There’s a big commercial enterprise that says this is not only possible, it already exists. But the science isn’t there yet,” Bidwill said.
Unlike measuring ethanol in breath, which is exhaled in copious amounts into a gaseous vapor, the main psychoactive component in cannabis (tetrahydrocannabinol, or THC) is carried in aerosol particles, which are small particles surrounded by fluid from deep within the lungs, the researchers said.
“With THC, it’s like looking for a needle in a haystack,” said Lofstead, who earned her doctorate in chemical engineering from CU Boulder.
THC also remains in fatty tissue, appearing in blood and fluids for weeks.
With alcohol, there is a clear relationship between blood concentration and impairment. But more THC in the blood does not necessarily mean more intoxication. Some people use cannabis regularly to treat medical conditions.
“I get emails all the time from lawyers trying to defend people whose blood draws indicate they have THC in their system but who insist they haven’t used it recently. It’s a big problem and a social justice issue,” Bidwell said.
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The researchers used a filter-based device to collect breath samples from 18 volunteers. Participants were asked not to use cannabis the day before giving their baseline samples or before the experimental session. Everyone was asked to purchase a specific strain of cannabis flower containing 25% tetrahydrocannabinol (THC).
One day, CU Mobile laboratory, a white Sprinter truck, parked in the participant’s driveway. After giving blood and breath samples in the van, participants were asked to go home, use cannabis, and return to the van to breathe into the collection device. Samples were shipped to NIST for processing and analysis.
Only eight participants showed the expected increase in tetrahydrocannabinol (THC) after cannabis use. In three post-use breath samples, no THC was detected. In several other samples, breath THC levels after use were similar to or lower than baseline levels.
“Our results do not support the idea that detection of THC in breath as a single measure can reliably indicate recent cannabis use,” the researchers said.
In future research, the NIST team hopes to gain a better understanding of the chemical properties of THC, try other ways to detect it through breath, and develop standard reference materials that laboratories can use to calibrate equipment.