The Safety of Marijuana: A Complex Issue
As the legal cannabis industry continues to grow, concerns about the safety of marijuana products have become increasingly important. In Colorado, where recreational marijuana was legalized in 2012, regulators have been working to ensure that products are tested for contaminants and pesticides. However, a lack of data on the long-term risks of these substances makes it difficult to guarantee a safe product.
Jeff Raber, CEO of The Werc Shop and an instructor at the University of Denver’s cannabis program, notes that “safe” is a relative term, as what is harmful to one person may not be to another. He explains that the same amount of a chemical in a batch of cannabis could be benign or harmful, depending on factors such as the size and health of the user, as well as how often and how much they consume.
Colorado requires growers to test their products for yeast, mold, bacteria, pesticides, and heavy metals, such as lead. Manufacturers must also test for residual solvents and chemicals used in the production process. However, regulators had to work with limited existing information on the possible risks of pesticides and contaminants in marijuana, as few studies have examined what levels might be safe in a smokeable or vapeable product.
A 2013 study co-authored by Raber found that significant amounts of pesticides could pass through water pipes or glass pipes to the user, even after filtration. While the risk to people using regulated cannabis now may be lower, the study predates the current pesticide limits in place.
Colorado’s updated 2013 pesticide regulations were based on rules in place in Canada, after a group of researchers and stakeholders considered various sets of standards used in other places with legal marijuana. The state’s Marijuana Enforcement Division referred questions about the standards used for different contaminants to the Colorado Department of Public Health and Environment, which declined to comment.
Ideally, more studies would settle what chemicals are risky in smokeable marijuana and whether any cannabinoids offset some of that risk. However, most research is still focused on understanding how the plant itself affects people who use it, and federal law limits researchers’ ability to grow and study cannabis.
The lack of direct data matters because not everything present on the bud makes it into the user’s body. For example, contamination with heavy metals would cause a problem in a concentrated or edible product, but lead and cadmium don’t turn into particles that users can easily inhale when smoking. Similarly, E. coli doesn’t fare well when set on fire, and the state of Colorado hasn’t had any marijuana
