Surely it’s not beyond the ability of Health Canada to come up with a users’ guide that could be handed out at cannabis stores.

Since the use of cannabis was legalized in 2018, the number of drivers injured while testing positive for the drug has more than doubled.

Specifically, the proportion of injured drivers who had blood concentrations above the legal limit stood at 3.8 per cent in 2018. By 2020 that number had risen to 8.6 per cent. The greatest increase was in drivers over 50 years of age.

While more recent figures aren’t available, such a dramatic surge in just two years suggests an ongoing trend.

Researchers from the University of British Columbia who uncovered those alarming numbers have called for heightened public information campaigns and tougher law enforcement measures to stem the rise.

They draw attention to the rapid rate at which THC — the active ingredient in marijuana — enters a person’s blood system.

While the legal maximum is two nanograms per millilitre of blood, THC levels can soar to 100 nanograms or higher within 15 minutes of smoking. It may take as long as four hours for the level to drop back to the legal limit.

That means anyone who gets behind the wheel of a car a short time after smoking marijuana may well be intoxicated. Anyone who smokes while actually driving is asking for trouble.

Stores that sell marijuana over the counter have been told they may not advise customers about safe quantities to consume unless their salesperson is a doctor.

Taken at any level, this is pure insanity. First, if these products are sufficiently intoxicating that it takes a doctor to give advice about their use, why are they being sold by staff who lack that expertise?

The view seems to be that it’s better to give customers no advice whatsoever, rather than medically imprecise information. But surely sales staff, while not physicians, can be trained sufficiently to offer some form of guidance.

If this cannot be done without six years in medical school, same question. Why are untrained staff permitted to sell such a hazardous product?

Second, why cannot some form of printed guide be handed out which advises customers, by age, sex and weight, how to use the various products?

As it stands, some marijuana derivatives such as cannabis oil can be sold with no instructions about dosing or application method on the container.

Surely it’s not beyond the ability of Health Canada to come up with a users’ guide that could be handed out at cannabis stores.

Evidently a rethink is needed, and fast. For it’s clear what has happened here.

The federal government rushed the legalization process without thinking through all of the potential implications.

If this were just another consumer product, that would be bad enough. But we’re talking about a drug that carries serious health risks.

And now we have evidence that when consumed while driving, marijuana poses a very real threat to public safety.

The last thing our overwrought health-care system needed was a decision, made in search of popularity, that will drive up hospitalization rates.

It is probably too late now to reverse course and de-legalize marijuana. Certainly there are no signs that the federal government has any intention of doing so.

Yet neither is there any indication that Health Canada realizes the dangers associated with inadequate public information or makeshift law enforcement.

We may hope that the UBC study, which was published in a prestigious medical journal, will capture Ottawa’s attention.

More likely, what it may take to generate action will be a spate of driving accidents. And that is no way to formulate and prosecute public policy.