They discover that marijuana users have high levels of lead and cadmium in blood and urine

2023-09-03 04:54:25

Marijuana may be a significant and underrecognized source of lead and cadmium exposure, according to research conducted at Columbia University’s Mailman School of Public Health, which detected significant levels of the metals in the blood and urine among users. of this drug. The results are published in the journal ‘Environmental Health Perspectives’.

This is one of the first studies to report biomarker metal levels among marijuana users and probably the largest to date linking self-reported marijuana use with metal exposure.

Measurements reported by participants who only smoked marijuana compared to those who used only tobacco resulted in significantly higher blood lead levels (1.27 ug/dL) and urine (1.21 ug/g of creatinine).

“Because the cannabis plant is a well-known collector of metals, we had hypothesized that people who use marijuana will have higher levels of metal biomarkers compared to those who do not use it. Therefore, our results indicate that marijuana is a source of exposure to cadmium and lead,” said Katelyn McGraw, a postdoctoral researcher in Columbia Public Health’s Department of Environmental Health Sciences, and first author of the study.

The researchers combined data from the National Health and Nutrition Examination Survey for the years 2005-2018. Operated by CDC’s National Center for Health Statistics (NCHS), NCHS NHANES is a biannual study program designed to assess the health and nutritional status of adults and children in the US.

McGraw and his colleagues classified the 7,254 survey participants by type of use: no marijuana/no tobacco, exclusive marijuana, exclusive tobacco, and dual use of marijuana and tobacco. Five metals were measured in blood and 16 in urine..

Marijuana is the third most consumed drug in the world, behind tobacco and alcohol. As of 2022, 21 states and Washington DC, covering more than 50 percent of the US population, have legalized the recreational use of marijuana; and medical marijuana is legal in 38 states and Washington DC

However, because marijuana remains illegal at the federal level, regulation of contaminants in all cannabis-containing products remains piecemeal and there has been no guidance from federal regulatory agencies such as the FDA or EPA.

While 28 states regulate the concentrations of inorganic arsenic, cadmium, lead, and total mercury in marijuana products, regulatory limits vary by metal and by state.

«In the future, research should be carried out on the consumption of cannabis and its contaminantsparticularly metals, to address public health concerns related to the growing number of cannabis users,” said Tiffany R. Sanchez, assistant professor of environmental health sciences at Columbia Public Health and senior author.