Is Vaping Cannabis Safe? Scientists Say the Risks May Be Different than Smoking

In the realm of alternative consumption methods for nicotine or cannabis, vaping has long been touted as a potentially “safer” option, particularly where legal regulations allow. However, the seemingly innocuous devices are now under increasing scrutiny as research and regulation shed light on their inherent risks.

A recent study has uncovered a concerning revelation: nano-sized toxic metal particles may already be present in cannabis vaping liquids, even before the liquid is heated within the device. This issue appears to be exacerbated in products lacking proper regulation.

The findings of this study will be unveiled today at the spring meeting of the American Chemical Society (ACS).

Canada’s Cannabis Act of 2018 makes cannabis federally legal, while U.S. regulations and legalization are still developing.

According to Andrew Waye, who will present the results at the symposium, “Cannabis vapes are newly regulated products in Canada, so we don’t yet have much scientific data about them.

“This is an opportunity for us to look at some of the questions concerning the risks and unknowns of cannabis vapes.”

Waye oversees the research program at Health Canada’s Office of Cannabis Science and Surveillance.

Vaping does not include a combustion process, which creates toxic chemicals, as smoking does. Rather, a vaping device warms a liquid until it turns into a vapor that can be inhaled. It is thus often seen as a safer way to consume nicotine or cannabis.

However, studies on nicotine vapes have shown that the heating element’s metal parts, which include nickel, chromium, and lead, may release dangerous elemental metals into the vape liquid. These metals may then travel into the aerosol and end up within the user’s body.

Waye’s group aimed to find out whether this also applied to vapes that included cannabis. To do this, the team worked with Zuzana Gajdosechova, a scientist at the National Research Council of Canada’s Metrology Research Centre, which has long been engaged in cannabis testing and standardization.

The team collected 41 samples of cannabis vape liquids: 20 from the Ontario Cannabis Store, which is a legal and controlled source, and 20 from the black market, which was supplied by the Ontario Provincial Police. Using mass spectrometry, the liquids were examined to check for the presence of twelve metals. Certain metals are often tested for in regulated cannabis products, along with other impurities.

Gajdosechova worked with imaging specialists to check the metal particles visually using methods like scanning electron microscopy, which helped the researchers validate their results. Certain metals, such cadmium, arsenic, and mercury, were found in cannabis products at levels that were deemed very high, while other elements, like arsenic, were found within the commonly recognized tolerance limits.

Lead was out to be the most notable example: some unregulated samples had 100 times the amount of lead than the regulated ones, considerably surpassing the widely acknowledged tolerance level.

Significantly, the liquid of cannabis vapes that were less than six months old and had never been used included this metal contamination.

According to Gajdosechova, “The evidence strongly suggests that metal contamination can come from the device when it’s produced, and not from the heating of the coils.

“But depending on the quality of the device, the contamination may be increased by that heating.”

They also discovered that vapes from the same manufacturing lot may have varying amounts of metal contamination, indicating a significant degree of sample variability. This may have an impact on testing protocols since, according to Canadian rules, testing must be done at or after the last stage when contamination might occur and samples must be representative of the whole lot or batch.

Waye states, “If contamination is happening when the device is assembled, you should be testing at that stage rather than earlier.”

Next, they sought to look into the size of the metal particles to determine their possible risk to health.

The team discovered several particles that were nanoscale in size using single particle inductively coupled plasma mass spectrometry.

According to Gajdosechova, “Some nano-sized metal particles are highly reactive and potentially harmful.”

The team’s next goal is to figure out how many of these particles enter the vape aerosol during device usage. It will be crucial for understanding the public health consequences of these results to establish if the metals may enter users’ lungs at this point. Researchers anticipate cannabis vapes to have the same impact as nicotine vapes, which have already shown it.

“Different types of cannabis products present different risks. Our research doesn’t answer whether vaping is riskier than smoking, it just underlines that the risks may be different. Previously uncharacterized risks with cannabis vaping are still being identified,” Waye says.

Hence, while there may not be a definitive method for consuming these products without risk, this study underscores the vital role of regulation in enhancing the safety of cannabis products across the board.

Source:  ACS Spring 2024

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