New findings suggest that individuals who exclusively use marijuana may be accumulating elevated levels of toxic metals in their bloodstream, a recent study reveals.
Researchers have discovered that those who solely consume marijuana exhibit significant concentrations of lead and cadmium in their bodies—these same toxic metals are present in certain cigarette smokers.
The cannabis plant, much like the tobacco plant, acts as a hyper-accumulator of metals. Katlyn McGraw, lead author of the study and a post-doctoral researcher at Columbia University Mailman School of Public Health, explains, “The plant absorbs metals from the soil and then deposits them in the leaves and the stems and the buds, so when the marijuana is smoked or inhaled people might be inhaling those metals.”
Among these metals are cadmium and lead. Even low levels of cadmium are associated with adverse health outcomes like heart and vascular disease. Lead, on the other hand, is a potent neurotoxin, particularly concerning for young individuals, and is linked to heart disease.
“It’s important to note that there’s no safe level of lead,” McGraw emphasizes.
In states where marijuana is legally accessible, its cultivation practices are regulated. However, as McGraw underscores, nationwide standards and safeguards remain lacking, and this situation will persist until legalization spans the entire United States.
McGraw contends, “We need federal regulation to make sure the new products coming into the market will be regulated for contaminants, not just metals, but also pesticides, molds, and other things.”
Potential consumers are encouraged to recognize the likelihood of exposure to toxic metals when considering the purchase of marijuana. McGraw advises individuals to assess their frequency and quantity of marijuana use, as this might lead to exposure to detrimental metals, known to be detrimental to health.
Dr. Peter Grinspoon, a cannabis specialist at Massachusetts General Hospital and Harvard Medical School, posits that legalized markets could likely circumvent the heavy metal accumulation seen in marijuana. He explains, “Cannabis and hemp are good at cleaning up soil, for example, after a toxic accident, as they suck the crap out of the ground.”
He stresses the importance of a legal market, which enforces mandatory testing, as heavy metal levels tend to be higher in illegal markets.
In their study, McGraw and her colleagues collected data from over 7,200 participants in a nationwide health survey conducted between 2005 and 2018. These participants exclusively used marijuana. The researchers measured the concentrations of five metals in participants’ blood and 16 in urine.
Individuals who solely consumed marijuana exhibited notably higher levels of lead and cadmium in both their blood and urine when compared to non-users.
Given that the data were self-reported, the researchers cannot definitively confirm that the participants’ metal exposure resulted exclusively from cannabis use. Nevertheless, it is strongly indicated.
This study contributes to existing research that highlights concerns about harmful contaminants in cannabis. Pat Aussem, vice president for consumer clinical content development at the Partnership to End Addiction, notes that cannabis, as a plant, can accumulate contaminants such as heavy metals, pesticides, molds, fungus, and residual solvents due to its growing and processing conditions.
Aussem underscores the unevenness of production regulation across the US, compounded by the prevalence of products and unscrupulous actors. She warns that, at times, manipulated or falsified lab results and product labeling mislead consumers.
Additional risks associated with cannabis use include interactions with medications, unintentional exposure to children and pets resulting in emergency room visits, developmental issues when used during pregnancy, disruptions to brain development in adolescents, impaired driving, and impacts on mental health such as depression, psychosis, and anxiety.
Consumers are encouraged to exercise diligence to ensure that their cannabis consumption doesn’t lead to unexpected issues. Aussem also calls for states to enhance their testing programs to ensure accurate labeling for adult cannabis consumers.