Marijuana contamination linked to lethal illnesses — and even legal weed can be unsafe: ‘It’s a horror story’

Two scientists, Jessica Ibarra and Tommie Griffin, work in a lab at CW Analytical Laboratories in Oakland, CA, testing cannabis for contaminants.
Two scientists, Jessica Ibarra and Tommie Griffin, work in a lab at CW Analytical Laboratories in Oakland, CA, testing cannabis for contaminants.

Does cannabis legalization mean a safer product? Not necessarily.

Anne Hassel, a 56-year-old physical therapist in Chicopee, Massachusetts, said she developed twitching muscles, numbness in her feet, nausea and cramps after using marijuana, only for doctors to find high levels of nickel, lead and cadmium.

“People consider that if it’s legal, it’s safe. It’s a complete fallacy,” the former cannabis user told the Wall Street Journal.

Gallup reports that an estimated 17% of Americans use marijuana.

An estimated 17% of Americans use marijuana products. Michael Moloney – stock.adobe.com
An estimated 17% of Americans use marijuana products. Michael Moloney – stock.adobe.com

As of 2023, 24 states had enacted regulations for recreational use, while even more have legalized the drug for medical use, and just last month, New York revealed new rules for growing the plants at home.

But contamination is quickly becoming an issue of concern. Users have reported high levels of heavy metals in their blood and urine, while some studies, per the Journal, have linked cannabis use to a higher risk of fungal infections, numbness, bleeding in the lungs and artery disease.

Marijuana plants are more likely to be contaminated because they are bioaccumulators, meaning they absorb things like heavy metals pesticides in the soil, as well as fungi.

Last year, an Arizona dispensary recalled a strain of cannabis called “Grim Reefer” after it was possibly tainted by a potentially life-threatening fungus called Aspergillus.

“People consider that if it’s legal, it’s safe. It’s a complete fallacy,” said Hassel, who experienced an adverse side effect after using the drug. Every Brain Matters
“People consider that if it’s legal, it’s safe. It’s a complete fallacy,” said Hassel, who experienced an adverse side effect after using the drug. Every Brain Matters

The same fungus was the cause for a mandatory recall of Gelato’s Orangeade hybrid flower sold in California and manufactured by Urban Therapies Distribution last month.

From 2017 to 2019, poison control centers saw an increase in cannabis-related calls, according to one study.

“It’s a horror story in some ways,” Virginia Commonwealth University professor and forensic toxicologist Michelle Peace told the outlet. “The general belief is that if it’s on the store shelf it must be safe, but it’s hard for the consumer to know.”

Sherer, who now advocates for marijuana safety, said she experienced “not normal” symptoms after using cannabis post-op. Courtesy Steph Sherer
Sherer, who now advocates for marijuana safety, said she experienced “not normal” symptoms after using cannabis post-op. Courtesy Steph Sherer

Washington, D.C., resident Steph Sherer called 911 after she experienced a racing heartbeat, hives, muscle weakness and nearly fainted when she consumed a gummy and a prescription drug post-surgery.

Sherer, who believes her symptoms were a result of contamination, said it was “not a normal reaction” and informed her state’s regulators and the dispensary from which she purchased the edibles. Now, she’s calling for consumer safety and more oversight as the head of Americans for Safe Access, an advocacy organization.

However, there are no definitive standards for contaminants in marijuana — some states have stringent guidelines to test for contaminants, while others do not, according to the Journal.

In other words, it’s “buyer beware,” warned Kevin Sabet, who worked as a White House Office of National Drug Control Policy adviser under the administrations of Bill Clinton Barrack Obama and George W. Bush.

California requires rigorous testing for contaminants in marijuana. AP
California requires rigorous testing for contaminants in marijuana. AP

While growers told the Journal they sell safe products and would be open to more standardized testing of cannabis products at the federal level, others find issues with the prospect, saying it could drive up the cost and consumers would flock to the unregulated black market instead.

“There are a lot of state-by-state discrepancies,” Arizona State University assistant professor Maxwell Leung, who is also on the state’s medical marijuana testing advisory council, told the outlet.

“No one should be exposed to harmful levels of pesticide and contaminants in cannabis.”