Compared to testing alcohol, checking for traces of cannabis compounds is exponentially more complicated. In the race to build a quick and reliable cannabis breathalyzer, scientists are looking to cutting-edge technologies in the fields of analytical chemistry and bomb detection.
Read on to understand how such new developments are influencing roadside testing methods for cannabis.
An instrument to sample vapor inside an old paint can, using PLOT-cryo (NIST photo)
A ground-breaking study, published by researchers from the National Institute of Standards and Technology (NIST), recommends using a unique testing method that leverages porous layer open tubular cryogenic (PLOT-cyro) absorption. PLOT-cyro was established in 2009 by Tom Bruno, a NIST chemist; which at the time was designed for detecting explosive substances and compounds at busy airports. Today, it is being utilized to support evidence for cases of arson.
Bruno believes PLOT-cryo could revolutionize cannabis testing by creating a foundation for standardization.
In cannabis detection, PLOT-cryo is capable of detecting THC on a molecular level. Unlike ethyl alcohol, THC compounds are difficult to measure because they possess very low vapor pressure. By comparison, high vapor pressure molecules are considerably lighter and escape more easily, making them easy to detect. Hence, traditional methods of roadside testing are not effective for cannabis. PLOT-cyro works by trapping THC compounds and analyzing the sample in the vapor phase.
“Vapor pressure describes how a compound behaves when it transitions from a liquid to a gas,” explained Tara Lovestead, a NIST chemical engineer and the lead author of the study, in a statement.
“That’s what happens in your lungs when a molecule leaves the blood to be exhaled in your breath. So if you want to accurately measure blood levels based on breath, you need to know the vapor pressure.”
Other scientists, from UC Berkeley and the University of Florida, are looking to ion mass spectrometry to improve success rates of cannabis breathalyzers. This method relies on filtering cannabis compounds using active particles. The process is very accurate, as it could tell researchers if the subject has consumed cannabis within a window of a few hours. However, it doesn’t provide data surrounding the amount of THC present in the subject’s bloodstream.
Classic Sobriety Test
The main issue with applying the same framework for alcohol testing is that both substances (alcohol and cannabis) differ greatly. An individual with high tolerance to cannabis could still function reliably after consuming large amounts; while a person with low tolerance may not be able to perform basic tasks, like driving, after a small dose. Because of this, using a breathalyzer device as a medium for cannabis detection may not generate accurate results.
“What matters is not the THC,” said Daniele Piomelli, a professor at the UC Irvine School of Medicine and an expert on cannabis. “What matters is if you are intoxicated.”
Piomelli suggests enforcing the classic behavioral field sobriety test as the main tool for detecting cannabis intoxication.
“There is understandably a strong desire by both lawmakers and the public to create legal limits for marijuana impairment in the same manner we do alcohol,” said Marshall Doney, AAA’s president and CEO. “In the case of marijuana, this approach is flawed and not supported by scientific research.”
A new study shows that fewer traffic deaths occur in states where medical marijuana is legal, than those without – especially among younger drivers. The study was conducted by researchers at Columbia University’s Mailman School of Public Health, and published in the National Journal of Public Health.
Their findings show that there is an 11 percent reduction in traffic fatalities, on average, in areas where medical marijuana laws are enacted. The study included a look at 23 states and the District of Columbia.
For those 45 and older, there was little evidence of reductions in traffic fatality rates. However, this age group is disproportionately represented in larger numbers amongst those enrolled in medical marijuana programs on the state level and that needs to be considered accordingly with the study’s findings.
But the most interesting statistic from the study by far is that the 15 to 44 age group of drivers had the largest reduction in traffic fatality rates in states where medical marijuana laws are in place.
The study also found that the presence of medical marijuana dispensaries correlated with fewer traffic fatalities. The study’s senior officer, Silvia Martins, a physician and associate professor, released a written statement that delved into the results further and shared her insights.
According to the written statement released by Martins,
“We found evidence that states with the marijuana laws in place compared with those which did not, reported, on average, lower rates of drivers endorsing driving after having too many drinks.”
She also went to state what other factors could partially account for the correlation such as “strength of public health laws related to driving, infrastructure characteristics, or the quality of health care systems.”
She further postulates that these lowered rates of traffic fatalities may be occurring in these states as a possible relation to lower levels of alcohol-impaired driving. In fact, it seems as though younger people are foregoing alcohol for marijuana, which might be a factor for these lowered rates. States with medical marijuana laws have seen a shift away from alcoholic beverages, and that could be a mitigating factor for a decrease in traffic fatalities.
However, the researchers also made sure to caution that these lowered rates were not consistent among all states that have medical marijuana laws in place. States such as California and New Mexico, for example, showed reductions in traffic fatality rates initially but then tapered back into average rates. Both states saw a respective initial reduction of 16 percent and 17.5 percent but saw a gradual increase after.
Researchers undertook this study due to increased focus on public safety in states where medical marijuana laws are in place. Considering that nine states have already passed medical marijuana laws between 2010 and 2014, with more states introducing similar measures, there will likely be a considerable increase on cannabis as it relates to public health and safety.
Previous studies conducted have found that cannabis might be linked to drivers weaving in traffic more, and having slower reaction times comparatively. Other studies have also found that drivers under the influence of cannabis may also linked to reduced speed and increased headways. This suggests that perhaps cannabis users are more aware of related impairment and try to compensate accordingly.
Quick facts about the study
Published online in the American Journal of Public Health
Analyzed traffic fatality data from the National Highway Traffic Safety Administration (NHSTA) from 1985 to 2014
Factors taken into account while conducting this study included: laws in place on graduating drivers licensing, bans on using cell phones and texting while driving, enforcing the usage of seat belts as well increasing speed limit to 70 mph or more.
Other factors such as median household income and unemployment rates were also considered.
In Colorado, like many states with legal marijuana, driving with a small trace of marijuana (5 nanograms) in one’s bloodstream results in a DUI. This results a legal conundrum: does marijuana in one’s system necessarily mean impairment?
If a recent Colorado ruling in favor of a “stoned driver” is any indication, that answer is a definitive no. Ralph Banks, a 27-year-old Ralph Banks of Lakewood, Colorado, had his cannabis DUI acquitted by a Jefferson County Court jury after a less than 30-minute discussion in the jury room.
Banks’ case dates back to last March (2015), when a missing headlight got him pulled over by the Lakewood police; he was given a roadside test, deemed “under the influence of cannabis”, then cuffed and handed a DUI. A blood test also revealed that Banks had 7.9 nanograms per milliliter of THC in his System, which is 2.9 milliliters over the legal limit.
However, last week’s jury threw the case out and called Banks innocent after a brief huddle, clearly deciding he wasn’t impaired. As one would expect, Banks deemed the whole ordeal a disaster.
“It was a nightmare. It was the worst experience of my life.”
But one man’s temporary nightmare could mean future bliss for medicated or high drivers all throughout Colorado. Banks’ attorney, well-known cannabis litigator Rob Corry seems to think this decision indicates as long as the driver isn’t impaired, he or she will be in the clear.
“Now with this case, it’s perfectly legal to get behind the wheel after consuming marijuana as long as you’re not impaired. And that’s the key. You can do it if you’re not impaired. If you’re impaired, do not get behind the wheel of a vehicle.”
Given this result, Corry’s logic seems at least somewhat believable. However, there are many mitigating factors in any case that can determine one’s guilt, and they all stem from proof of impairment.
Banks’ case was pretty cut and dry, because a missing headlight isn’t like swerving in and out of lanes or stopping at a green light. Perhaps Banks’ headlight was caused by stoner indifference, but it’s more likely it was just an honest mistake warranting a citation, not a roadside drug test.
Still, there is plenty of evidence in favor of the hypothesis that medicated–but not impaired–drivers will continue to win these cases as they arise. Last year, a woman in Colorado also had her DUI acquitted in a very similar scenario; in 2013 a Michigan man set the first precedent for these types of cases when a court also dropped his marijuana DUI charge.
Moreover, numerous studies–even one by the government–have shown empirical evidence that drivers high on cannabis are 60 times safer than those on alcohol. In fact, the government study even claims that drivers on marijuana
“were no more likely to crash than who had not used any drugs or alcohol prior to driving.”
That may be a slight exaggeration, but it’s clearly safe to say that driving on marijuana clearly does not pose the threat driving on alcohol, pain killers, or harder drugs presents. While it’s still not a good idea to get behind a wheel right after consuming cannabis in most circumstances, these recent rulings and science show that you’re not really putting anyone at risk, nor are you committing a crime.
For some medical marijuana patients, like those with Parkinson’s, it’s not difficult to see how cannabis could in fact improve one’s driving. Cannabis (CBD in particular) has the ability to cease shaking and steady hands down.
Would you rather have that driver on his medicine or “stone” sober.
As a larger number of states legalize recreational cannabis — joining Alaska, Colorado, Oregon, Washington, and the District of Columbia — the issue of driver impairment is becoming a more hotly debated topic. Although libertarians may argue the rights of individuals to consume cannabis or operate vehicles under a variety of conditions, the issue of protecting innocent citizens and the dependability of safe roads obviously percolates to the surface.
What is Cannabis Intoxication?
The state legislature in Colorado has established a THC limit for “safe” drivers that is five nanogram-per-milliliter (ng/ml). If an officer suspects that a driver is impaired by cannabis, he or she may administer a blood test to determine the THC level. Other legal states obviously must also define and adopt legislation for issues such as “impaired driving” and “cannabis intoxication.”
The scant research and studies that have been conducted regarding the effects of cannabis on human motor skills like driving have revealed that average cannabis consumption mildly impairs psychomotor skills — but that the impairment is neither severe nor long in its duration. How does this minor impairment affect driving skills? According to NORML, during driving simulation tests, the loss of driving skill is typically manifested in decreased driving speed (arguably a good thing in most situations). However, it also typically results in slower response times to emergency situations (definitely not a good thing).
Considering that humans like to sling two-ton pieces of automotive metal down highways and freeways at legal speeds up to 85 MPH in the United States, driver impairment and the protection of society is no small issue for the cannabis community.
Molly Jansen, a progressive and curious defense attorney in Colorado questioned:
“It’s important for people to say: Alright, I may be a chronic smoker, but right now, can I drive?”
In unincorporated Adams County, Colorado, both prosecutors and defense attorneys are leveraging real life testing demonstrations to prove their point in court. Dubbed “green labs,” the tests involve volunteers from a local cannabis lounge who are given varying amounts of pot edibles. After the edibles have taken effect (typically 60-90 minutes), participants were asked to undergo a standard roadside sobriety test that included walking a straight line and following the tester’s finger with only their eyes.
Participants Overly Optimistic
Jansen orchestrated a green lab demonstration using volunteers from the iBake cannabis lounge in Adams County. Prior to testing, all participants — each of which admitted to being a regular cannabis user — stated that they believed the consumption of cannabis would have no detrimental effect on their driving skills. Said one participant: “I’ll drive after smoking.” A few went as far as declaring a perceived increase in driving skill after smoking cannabis.
Jansen posed the question:
“Even if I smoke all day, every day, for three years, can I get behind the wheel of that car and be safe in this community?”
Such questions are critical for not only regular lifestyle consumers, but also patients. Those undergoing chemotherapy or suffering serious, life threatening conditions like cancer, Crohn’s disease, or arthritis — who often have no choice but to medicate daily and sometimes almost hourly to manage pain or nausea — must also get behind the wheel of passenger and commercial vehicles. Such patients must seriously consider their fitness for driving and the safety of those around them.
Many patients, especially those with conditions like multiple sclerosis and epilepsy, are, unfortunately, so sick they are unable to work, housebound, or not permitted to hold a driver license. Most patients, however, must commute to their jobs or drive errands within their communities to provide for their families and manage their homes. Can patients consume cannabis throughout the day and still be capable of driving safely? How does tolerance influence the effect of potent medicinal cannabis on patients?
How Did They Fare?
How did participants fare, especially considering that all perceived they would experience no decrease in driving ability and safety? Each person failed their initial roadside sobriety test. Only one hour later, however, several of the participants passed the sobriety test, with experts deeming them safe to drive on the road.
“Oh, I’m really, really high,”
Said one young female participant who passed her second test with flying colors. The test administrator commented, “It’s surprising that, if she says she’s that high, that she actually passed the road sobriety test the way she did…’cause she did everything perfectly.”
The green labs test aptly illustrated the fact that states and cities cannot simply legalize medical or recreational cannabis and then abandon the issue. To ensure the safety of all drivers, both cannabis users and otherwise, more informal and formal studies like the green labs must occur, with large volumes of data gathered and analyzed in a science-based approach to the issue. Until this happens, patients, law enforcement officials, recreational cannabis consumers, and lawmakers in states where it is legal will find themselves confused by what is — and is not — legal when behind the wheel of a vehicle.
Unfortunately, the U.S. Congress has done everything in its power to prevent research of cannabis medicine, including the effects of pot on daily tasks like driving. Until more research is conducted on the efficacy of the kind herb, including human trials, ignorance will pervade among patients, lawmakers, and lifestyle users.
Hopefully other states like Oregon, Washington, and California will pursue their own green labs in an effort to better understand the real world effects of regular cannabis consumption for patients and lifestyle consumers when it comes to tasks like driving, performing one’s job, or raising children.