With the push to legalize marijuana nationwide gaining steam, law enforcement across the country has become more concerned about drivers operating motor vehicles while under the influence. Legalization has further caused researchers to scramble to find a way to quickly detect marijuana without requiring lab testing.
Hound Labs in California claimed to have made a big breakthrough in 2018 with what the company called their own marijuana breathalyzer.
The company's device worked by having a person breathe into the breathalyzer for 30 seconds. The device worked to detect any level of THC in the breath and is said to be able to detect marijuana use within the last two hours prior to taking the test.
University of Pittsburgh researchers created a similar device which was studied, and the results were published in ScienceDaily. The device was created using carbon nanotubes which are 100,000 times smaller than a human hair. The device works by the binding of THC molecules to the nanotubes, which causes electrical properties to change. The device will detect how fast the electrical currents recover to determine if THC is present in the person's system.
Nanotechnology sensors are highly accurate and are used in the device to offer a gold standard in THC detection.
Machine learning was used to teach the breathalyzer how to accurately detect the presence of THC. The nanotube technology used in the device is relatively new and allows for the detection of THC levels that are comparable and even better than mass spectrometry.
"Accurate detection of THC levels in the body are needed when a driver is operating a vehicle under the influence of cannabis. Until now, there has been no reliable way for law enforcement to accurately detect THC levels in the body without extensive lab work being performed," states Tsion Chudnovsky, JD, a California DUI attorney.
"Convicting a driver for marijuana DUI requires that prosecutors prove beyond a reasonable doubt that the driver was driving under the influence of THC at the time of the stop. This requires a scientifically proven and reliable breathalyzer-type technology," according to Chudnovsky.
The University of Pittsburgh device was developed by an interdisciplinary team led by Alexander Star, PhD, professor of chemistry and Ervin Sejdic, PhD, associate professor of electrical and computer engineering at the Swanson School of Engineering. Unlike current blood, urine or hair sample testing methods that cannot be done in the field, this new device measures THC in a user's breath.
The device, which has been in development since 2016, is said to be ready for mass production. One characteristic of the device is it is not able to determine the amount of THC in the person's body or the level of impairment that they have sustained. Unlike blood alcohol concentration limits and guidelines, no such guidelines exist for marijuana consumption.
The breathalyzer can be set to determine only a specific threshold amount of THC to help avoid detecting THC in the breath days after a person used marijuana. The researchers who created the device had to wait months for approval from the Drug Enforcement Administration to work with THC.
Even though the DEA is moving to increase allowed cannabis production, it is still a Schedule I substance, making it very difficult for universities to conduct any form of research on the drug without government approval.
University of Pittsburgh researchers are continuing to test the prototype device, but are looking to move soon to manufacturing and make the device widely available to law enforcement. Their goal is to make the roads safer in this new era of legalized marijuana.
