Mold is all around us, but what happens if you smoke moldy marijuana?
Marijuana has long held a place in American political and pop culture, from “Reefer Madness” to “Dazed and Confused,” the infamous green plant is instantly recognizable. But the place it’s held in our lungs is not as well documented.
As marijuana becomes increasingly accepted and legal, each state has a patchwork of safety standards. Michigan’s largest recall has drawn a closer look at what the state is finding and what it’s missing.
Whether it was bought on the black market during the era of “free love” or legally purchased from the shelves of a dispensary just this year, there’s a chance the bud Michigan smokers inhaled had mold or other contaminants in it.
What are the real health concerns surrounding marijuana? The short answer: No one really knows since its prohibition has stymied long-term health studies.
“Obviously, the science that would typically come from the federal government in these types of situations isn’t available on the cannabis side,” Michigan Regulatory Agency Director Andrew Brisbo said. “So that puts us all in an interesting predicament when it comes to how to protect health, safety and welfare.”
A recall of an estimated 64,000 pounds of marijuana raised alarm bells in Michigan last fall. Some of the bud in question tested high for levels of yeast and mold.
Nearly 11% of all marijuana flower failed testing between March 2021 and February 2022, according to data provided by the MRA. The vast majority of all failed tests were for total yeast and mold, nearly 90%.
Industry experts interviewed by MLive consider Michigan’s standards to be some of the most comprehensive for testing. But that doesn’t necessarily mean the strictest when comparing metrics to other states.
Illinois allows up to 1,000 CFU/g for “total yeast and mold” in both adult use and medical marijuana. A colony forming unit is a term for viable and detectable yeast or mold.
Michigan standards for total yeast and mold are less stringent. Acceptable levels are up to 100,000 CFU/g for recreational and up to 10,000 CFU/g for medical marijuana.
The most concerning being a fungus called Aspergillus, which accounted for nearly 13% of all 11,734 failed safety tests in 2021.
Michigan is among the few states testing for Aspergillus which can develop into a fatal lung infection. Any detection of Aspergillus automatically disqualifies it for sale in Michigan.
Aspergillus poses the greatest risk because its spores can sit in the body undetected for years and then flare up when the immune system is weakened. Dr. Jordan Tishler, faculty member at Harvard Medical School and President of the Association of Cannabinoid Specialists, likens it to a seed sprouting after sitting dormant.
“The 20-year-old who’s healthy might have no initial reaction to inhaling Aspergillus spores,” he said. “But when that person gets to be 70 and develops colon cancer, or something else unrelated, that may reactivate spores that he or she inhaled decades earlier.”
In general, the consequences of using contaminated cannabis, including that which tests positive for Aspergillus, are higher for those who are immunocompromised.
Oregon does not test for Aspergillus stating that “the mold is so common in the environment that a person could pick it up many different ways.” Instead, the Oregon Health Authority has opted to put a cautionary label on products warning immunocompromised users of the risk.
Fungi is all around us – from the bread that got left out on the counter to the mushrooms on a pizza. Overwhelmingly its harmless to humans. However, most interactions with mold are through eating which sends the fungi directly into an acid bath in the stomach.
What the cannabis industry is left debating is what happens when that mold is ignited, inhaled and seeps into the thin membrane of our lungs?
Regulation in the cannabis industry should be stricter until there’s enough data to rule out which types of molds are not harmful when inhaled or vaporized, Tishler said.
“The safest response is to regulate tightly,” Tishler said. “As you accumulate future data, you can relax those standards if the data support that.”
Conversely, some believe the fire used to ignite marijuana before it hits the lungs actually protects users by killing microbes.
Cassin Coleman is director of quality and processing at Carbidex, a group of Michigan marijuana businesses. She analyzes marijuana safety standards across the nation, including making in-person visits to labs her companies plan to use.
She believes marijuana is overwhelmingly safe but supports required testing for known pathogens, dangerous chemicals, metals and an abundance of mold.
“I have an immunocompromised spouse, so I think about these kinds of things,” Coleman said. “For the average customer, that’s not immune compromised … this is not an issue. The process of combustion is going to kill everything anyway. You’re probably not going to be exposed to enough mold spores to have a problem.”
Coleman noted studies conducted in other states indicate up to 20% of marijuana that’s sold in dispensaries, after passing state testing, is found to have yeast and mold above established thresholds.
She also points to the decade’s long history of black-market smokers that hasn’t led to a trend of lung infections.
“I don’t think there is anything different today about the type and style of microorganisms attacking the cannabis plant that we’re testing for than there was 30 years ago before anybody started testing,” she said.
Coleman noted that other states, like Washington, don’t test for total yeast and mold growth, only for forms known to be potentially harmful.
“They believe the only harms are going to come from the pathogenic forms,” Coleman said. “I’m also in that camp. These things are not going to harm you. They may not taste good, they may not look pretty, but for the average consumer it’s pretty low risk.”
Mac Hyman, the quality manager at Iron Labs in Walled Lake, said labs test for pesticides in popular fungicide used on plants that are known to be cancer-causing, but a lot of what’s tested for has unknown health risks.
“Everyone is afraid of combustion right now and how that’s going to hurt you,” Hyman said. “I don’t think there is a study of smoking that stuff, versus eating it and ingesting it, which is really what needs to be researched.”
In 2016, an epidemiologist from the Centers for Disease Control and Prevention analyzed health insurance claims from patients with fungal infections looking to test for a correlation between marijuana smokers and the severity and frequency of infection.
The study found marijuana smokers were 3.5 times more likely to develop a fungal infection compared to claimants who did not smoke marijuana. Those smokers were also more likely to be younger, immunocompromised and hospitalized for the fungal infection.
There are big variables to consider: how the marijuana is grown, the immune system of the user and additional substance abuse.
Dr. MeiLan King Han, Chief of Pulmonary and Critical Care at the University of Michigan, notes that most marijuana smokers are also tobacco smokers so it’s hard to separate the effects in a true control group.
Even so, there isn’t much data suggesting marijuana leads to severe effects like the lung disease emphysema often seen in cigarette smokers, Han said.
The other x factor is time.
Some users may have immediate allergic reactions if they’re susceptible to mold, but other contaminants like heavy metals and pesticides might go undetected by the smoker until they accumulate and become cancerous.
“The lungs can actually take quite a bit of damage before you’ll notice,” Han said.
Health complaints aren’t easily accessible to the public, so little is known about how frequently consumers are experiencing negative health effects connected to licensed marijuana purchases.
There were 22 health complaints specifically linked to marijuana that was part of the recall. The complaints were filed both by retailers on behalf of customers and customers themselves.
Reactions varied including reports of increased seizure activity, allergic reactions, chest pains, flu-like symptoms, paranoia, a “chemical burning sensation” and at least two emergency room visits.
The health complaints are still under investigation by the MRA, Brisbo said during an interview with MLive on March 2. The MRA doesn’t currently compile data regarding adverse health complaints but they plan to in the future, Brisbo said.
The overarching message from medical professionals is that we don’t know what we don’t know so each joint is its own case study.
“As a lung doctor, when my patients ask me about marijuana use, I usually just tell them do whatever you feel is right – I’m just asking you not to smoke it,” Han said.
