New Study Finds Marijuana Users Have Higher Levels of Lead and Cadmium in Their Blood and Urine
A new study published in the journal Environmental Health Perspectives has found that users of marijuana have statistically higher levels of lead and cadmium in their blood and urine compared to non-users. The study analyzed data from the annual National Health and Nutrition Examination Survey, which tracks the health of Americans, between 2005 and 2018.
Lead author Tiffany Sanchez, an assistant professor of environmental health sciences at Columbia University Mailman School of Public Health, revealed that marijuana users had 27% higher levels of iron in their blood and 21% higher levels in their urine. Lead levels in their blood were 22% higher than non-users, and their urine contained 18% higher levels of cadmium.
Sanchez explained that both lead and cadmium remain in the body for extended periods and can have adverse health effects. Cadmium has been linked to kidney disease, lung cancer in people, and fetal abnormalities in animals. The US Environmental Protection Agency has set specific limits for cadmium in air, water, and food due to its toxic properties.
Dr. Beth Cohen, a professor of medicine at the University of California, San Francisco, and co-director of a program in residency investigation methods and epidemiology, emphasized the need for more detailed studies on cannabis, particularly considering the different types of products available on the market.
This study is unique as it examined heavy metal levels in the blood and urine of cannabis users, rather than just measuring the metal levels in the cannabis plants themselves. The study did not differentiate between medical and recreational cannabis use, so future research is needed to determine if medical cannabis users specifically have higher metal levels.
Heavy metals, such as lead and cadmium, have been associated with cancer, chronic disease, and neurotoxic effects. While heavy metals are present in other substances like tobacco smoke, certain e-cigarettes, and common food products, the study focused on marijuana due to its status as a “known hyperaccumulator.” This means that the plant absorbs heavy metals and other potentially harmful chemicals without harming itself.
However, the ability of cannabis to absorb heavy metals raises concerns for marijuana users, especially considering the lack of oversight and regulations in the cannabis industry. Few states have regulations in place regarding heavy metals in recreational or medical cannabis, and the source of the plants is often unknown when purchased from independent sellers.
The study concludes by highlighting the need for further research on the bioengineering of cannabis to absorb even greater levels of toxins. As for protecting themselves from contaminants, marijuana users are advised to have a varied diet and be aware of potential environmental contaminants in cannabis products.