It’s only a matter of time before breath detection devices, targeting drivers who are too high to drive, will be in the hands of enforcement agencies.
School of Engineering Professor Mina Hoorfar, who runs UBC Okanagan’s Advanced Thermo-Fluidic Lab, has been working on a device for several years using her ‘artificial nose’ technology—creating microfabrication appliances that are able to recognize hazardous molecules. The sensors can be fine-tuned to catch even the faintest amounts of targeted materials.
“Advances in microfabrication and nanotechnologies are enabling us to work at a smaller scale and with improved sensitivity,” explains Hoorfar. “We have responded to a need from regulators in North America to develop tools to accurately monitor tetrahydrocannabinol (THC), and the artificial nose lends itself to this application.”
In addition to her own technology, Hoorfar recently supervised a study of the five leading styles of THC breathalyzers that are either currently commercialized or under development. The review, led by doctoral student Hamed Mirzaei, looked at the prototypes and analyzed the science behind each one.
“Despite its large potential, breath analysis still has several technical difficulties,” says Mirzaei. “A healthy person can exhale a complex mixture of inorganic gases and many of these chemicals are from sources such as smoking, food consumption, bacterial microflora, work environments and medication.”
Diet, age, body mass index and gender can also influence the exact composition of a person’s breath, Mirzaei adds.
Other factors like temperature, humidity and operator training can influence the test results, meaning the science behind the tiny hand-held tool needs to be precise and reliable.
“As the size of sensors continue to decrease, and their sensitivity increases, we are getting closer to offering real-time, portable and accurate detection,” Hoorfar adds.
She says THC, in particular, is a tricky molecule to work with given that its concentrations in breath are quite low—estimated as up to 250 parts per trillion.
“This is a challenging detection limit that breath analyzers approaching the market must consider,” Hoorfar explains.
However, if THC is consumed during smoking, some particles will be deposited on lung tissues. These particles can be removed by exhalation and detected in breath—even three to six hours after someone has inhaled cannabis and when most behavioural and physiological effects associated with impairment have worn off.
“With legalization of cannabis consumption in Canada and many parts of USA, it is vital to create and improve technologies for public safety and awareness,” adds Hoorfar. “Breath analysis is not only the fastest technology available but it’s also a reliable and portable method to detect recent cannabis use and impairment. We just need to create the perfect device.”
Hoorfar says considering these platforms are relatively novel technologies to monitor THC in breath, they are not yet fully tested and understood. Meaning it may be a while before any are in everyday use.
“One day, in the not so far future, we will have portable devices that can tell us if we have a particular illness, or if there are dangerous fumes in our vicinity,” says Hoorfar. “And our team works hard every day to make that future a reality.”
The review, partially funded by the Canadian Foundation for Innovation Fund and a grant from the Natural Sciences and Engineering Research Council, was published in the Journal of Breath Research.