A new study has found that marijuana users have statistically higher levels of lead and cadmium in their blood and urine compared to people who don’t use the drug.
Researchers combined data collected by the National Health and Nutrition Examination Survey (NHANES) between 2005 and 2018. The study, conducted among a group of 7,254 adult participants, measured five metals in participants’ blood and 16 in their urine using an analytical technique that can be used to measure elements at trace levels in biological fluids.
The group was split into four groups—non-marijuana/non-tobacco users, exclusive marijuana users, exclusive tobacco users, and dual marijuana/tobacco users.
Among the participants, researchers found that 358 individuals who exclusively used marijuana in the last 30 days had 1.27 μg/dL (micrograms per deciliter) lead in their blood compared to 0.93 μg/dL in non-marijuana/non-tobacco users, a 27 percent increase. They also found that cannabis users had 1.22 μg/dL mean cadmium levels in their blood, or a 22 percent higher level than non-users.
When researchers collected data from participants’ urinary metal levels, they found that those who exclusively used marijuana had 21 percent higher levels of lead and 18 percent higher levels of cadmium, said Tiffany Sanchez, lead author of the study and assistant professor of environmental health sciences at Columbia’s Mailman School of Public Health.
Cadmium and Lead
Cadmium is a naturally occurring element used in products such as batteries, pigments, metal coatings, and plastics. It is also found in cigarette smoke and absorbed into plant and animal foods that people eat, according to the U.S. Centers for Disease Control and Prevention (CDC).When consumed in large amounts cadmium can cause stomach issues, and when inhaled at high levels it can lead to lung damage or death. Cadmium is considered a cancer-causing agent.
“Exposure to low levels of cadmium in air, food, water, and particularly in tobacco smoke over time may build up cadmium in the kidneys and cause kidney disease and fragile bones,” the CDC notes.
Cannabis Consumption
In recent years, marijuana consumption has been on the rise across the United States. As of 2019, more than 48 million people—or 18 percent of Americans—reported using the substance at least once in the last year.Marijuana, which is the third most commonly used drug in the world behind tobacco and alcohol, is legal for recreational use in 21 states, covering more than 50 percent of the U.S. population. People who use marijuana solely as a medication, meanwhile, are permitted to do so in 38 states.
Although nearly 40 states have legalized the substance in some form, it remains completely illegal in some states and at the federal level.
The substance is currently classified as a Schedule I drug under the Controlled Substances Act, meaning it has a high potential for abuse and no accepted medical use, along with drugs like heroin and LSD.
HHS is recommending reclassifying marijuana to say it has a moderate to low potential for dependence and a lower abuse potential, which would put it in a class with ketamine and testosterone.
If marijuana classification were to ease at the federal level, that could allow major stock exchanges to list businesses that are in the cannabis trade, and potentially allow foreign companies to begin selling their products in the United States.
“DEA should now quickly follow through on this important step to greatly reduce the harm caused by draconian marijuana laws,” Mr. Schumer said.
