Marijuana users have much more lead and cadmium in their blood and urine, study finds
People who use marijuana have statistically more lead and cadmium in their blood and urine than those who don't, according to a new study.
Marijuana users in the test group had 27% higher levels of lead in their blood and 21% higher levels in their urine compared to people who don't take weed, according to the Environmental Health Perspectives study published Wednesday. Users also had 22% higher cadmium levels in their blood 18% higher levels in their urine than non-users.
“Both cadmium and lead stay in your body for quite a long time,” lead author Tiffany Sanchez, an assistant professor of environmental health sciences at Columbia University Mailman School of Public Health said, according to CNN.
“Cadmium is absorbed in the renal system and is filtered out to through the kidney. So, when you’re looking at urinary cadmium, that’s a reflection of total body burden, how much you have taken in over a long period of chronic exposure.”
Survey shows: Half of Americans have tried marijuana. See how many say they still do.
No amount of lead in the body is considered safe, according to the U.S. Environmental Protection Agency. The agency said lead exposures have declined in recent decades but still pose serious risks to public health.
The EPA also considers cadmium exposure harmful as it has been linked to kidney disease and lung cancer in people, and fetal abnormalities in animals. The EPA has set specific limits for cadmium in air, food and water.
"Our results suggest marijuana is a source of cadmium and lead exposure," the study said. "Research regarding cannabis use and cannabis contaminants, particularly metals, should be conducted to address public health concerns related to the growing number of cannabis users."
Marijuana is the third most used drug globally, according to the findings.
Study measured blood and urine of over 7,000 users
The study examined blood and urine tests of 7,254 people who said they used marijuana in the past 30 days, to examine levels of heavy metals.
The study differed from most that measure metal levels in the cannabis plants rather than people consuming weed, Sanchez told CNN. It also examined data between 2005 and 2018 from the annual National Health and Nutrition Examination Survey, which tracks the health of Americans.
Sanchez said the study could not examine whether the self-reported cannabis users were using medical or recreational marijuana, CNN reported. She said a future study should evaluate that to help definitively determine whether medical or recreational users had higher metal levels.
Substance use in the United States
Over 61 million Americans ages 12 and older have used illicit drugs as of 2021, with the most common being marijuana, according to data released by the Substance Abuse and Mental Health Services Administration's National Survey on Drug Use and Health. The date shows 52.5 million people used cannabis in 2021.
The National Center for Drug Abuse Statistics said drug abuse and substance disorders are more likely found in young males, with drug use the highest among people ages 18 to 25.
As of 2021, "nearly 2 in 5 young adults 18 to 25 used illicit drugs. 1 in 3 young adults 18 to 25 used marijuana," according to the National Survey on Drug Use and Health.
Most American adults "consume alcohol at least once in their lifetime," and an average of more than 140,000 die from the effects of alcohol every year, the National Center for Drug Abuse Statistics said.
Marijuana use statistics relating to age, gender and education
Half of Americans for the first time say they have tried marijuana at one point, according to Gallup annual Consumption Habits survey released earlier this month.
Gallup has previously shared that current cannabis use is most common with young adults, ages 18 to 34, representing 29%. Adults ages 35-54 represent 17% of current use and adults ages 55 and older make up 9%.
The difference between men and women using cannabis isn't significant, according to Gallup. Meanwhile adults without a college degree are nearly twice as likely to smoke weed than college graduates. Only 12% of Republicans consume marijuana while 21% of Democrats and 17% of independents do.
Contributing: Thao Nguyen
This article originally appeared on USA TODAY: Study: Marijuana users have over 20% lead and cadmium in blood, urine
