The Problem With Pot
Updated: Jan 10, 2019
On October 17th, the federal government of Canada completed the process of making marijuana legal for recreational use. Barriers that had previously been in place defining medical indications for prescription and usage guidelines were largely removed for the greater population, making way for elective use. However, some questions remain regarding whether or not proper diligence was exercised in the process, and how to go forward.
People working safety-sensitive positions in the workplace have always been under the microscope for their substance use, medicinal or otherwise, because inattention could have grave consequences for the individual and those working around them. Guidelines were developed and used to establish reasonable suspicion of intoxication by observing telltale behaviors of drug or alcohol influence such as slurred speech and dilated pupils. Based on suspicion, followup urinalysis, breath or blood tests could be used to confirm intoxication by the proxy metric of blood concentration. While this isn't perfect, it could give a sufficient indication. Blood alcohol and its effects per concentration is well studied subject and is generally well understood, and other substances (not divulged as prescription beforehand) were treated as zero tolerance. Thus, we see the issue: how do we treat pot?
The current best approach has to do with comparing a constellation of different symptoms of marijuana influence to establish level of intoxication. Field tests such as the ones used to measure blood alcohol (breath) would be of little use, even if they existed, so we find ourselves falling back on 'walk a straight line, touch your nose'. Sleep deprivation, exposure to certain chemicals and other physiological factors can produce many of the same signs as intoxication, and the problem of subjectivity is also reintroduced. A breath test gives a metric, where a tester gives a subjective interpretation of observations. Psychology tells us that humans are rife with bias and very poor at being objective - we're even poor at knowing when we're succumbing to bias!
Alcohol, and the way it is metabolized and stored in the body is a poor analog for cannabis. It is convenient to compare the two simply because they both live in the recreational substance community and maybe have a thing or two in common in terms of how they make one feel. The mechanism of action and the biology of how these substances act is another story. Blood concentration simply isn't a particularly useful way to determine how "high" someone is on cannabis, and the fat solubility of THC means that it can be stored in the body weeks or possibly even months after use. Since it is legal to use, it becomes difficult to make a good faith argument for zero tolerance within an organization, but some are doing so, lacking any reliable recourse. Perhaps that represents an over-reach for those employers but they have little to work with. Even as it stands, conflict exists between provincial OH&S legislation and human rights legislation at the federal level. It is easy to imagine how this is going to raise more issues.