a columbia university This study found high metal concentrations in the blood and urine of marijuana users, highlighting potential health risks and highlighting the need for consistent regulation.
A recent study conducted at Columbia University’s Mailman School of Public Health found significant levels of the metal in the blood and urine of marijuana users. These results suggest that marijuana may be an important yet under-recognized source of lead and cadmium exposure.
This is one of the first studies to report biomarker metal levels in marijuana users, linking self-reported marijuana use to internal measures of metal exposure, rather than simply looking at metal levels within cannabis plants. , probably the largest study to date. The results were published in the magazine on August 30th. Environmental hygiene perspective.
Main findings
Participants reported significantly higher blood lead levels (1.27 μg/dL) and urine (creatinine 1.21 μg/g creatinine) when using marijuana alone compared to non-marijuana cigarettes. .
“Since the cannabis plant is a known metal scavenger, we hypothesized that people who use marijuana would have higher levels of metal biomarkers than those who do not use marijuana,” said Columbia Department of Public Health, Environmental Health Sciences. said Caitlin McGraw, a postdoctoral fellow in the department. , and first author. “Our results therefore indicate that marijuana is a source of exposure to cadmium and lead.”
research method
Researchers combined data from the National Health and Nutrition Examination Survey from 2005 to 2018. NCHS NHANES, led by CDC’s National Center for Health Statistics (NCHS), is a biannual research program designed to assess the health and nutritional status of adults and children in the United States.
McGraw et al. categorized 7,254 study participants by usage: non-marijuana/non-tobacco, dedicated marijuana, dedicated tobacco, and combined marijuana and tobacco. Five metals were measured in the blood and 16 metals in the urine.
The researchers used four variables from NHANES to define marijuana and tobacco use only. namely, current smoking amount, serum cotinine level, self-reported previous marijuana use, and recent marijuana use. Tobacco-only use was defined as an individual who answered “yes” to “Do you currently smoke cigarettes?” or whose serum cotinine level was >10 ng/mL.
Marijuana prevalence and regulation
Marijuana is the third most commonly used drug in the world after tobacco and alcohol. As of 2022, 21 states and Washington DC, covering more than 50% of the US population, have legalized recreational use of marijuana. However, because marijuana remains illegal at the federal level, regulation of contaminants in all cannabis-containing products remains piecemeal, with no guidance from federal regulatory agencies such as the FDA or EPA. As of 2019, 18 percent of Americans, or 48.2 million people, reported using marijuana at least once in the past year.
Twenty-eight states regulate the concentrations of inorganic arsenic, cadmium, lead, and total mercury in marijuana products, but regulatory limits vary by metal and state.
“Moving forward, we need to conduct research on cannabis use and cannabis contaminants, especially metals, to address the public health concerns associated with the growing number of cannabis users,” said Associate Professor of Environmental Health Sciences at the Public University of Colombia. said Dr. Tiffany R. Sanchez. Health, Senior Author.
Reference: “Blood and Urinary Metal Levels in Exclusive Marijuana Users in NHANES (2005-2018)” Katlyn E. McGraw, Anne E. Nigra, Joshua Klett, Marisa Sobel, Elizabeth C. Oelsner, Ana Navas-Acien , by Xin Hu Tiffany R. Sanchez, August 30, 2023, Environmental hygiene perspective.
DOI: 10.1289/EHP12074
The co-authors are Ann E. Nigra, Joshua Klett, Marisa Sobel, Ana Navas Asien of the Colombian Public Health Agency. Elizabeth C. Elsner, Columbia University Irving Medical Center, and Xin Hu of Emory University School of Medicine.
This research was supported by: National Institutes of Health (NIH) National Institute of Environmental Health grants P30ES009089 and T32ES007322.