In a recent investigative report by Steven Reinberg, a medical journalist, some previously unreported characteristics of marijuana use raised concern.
It appears that those who use marijuana regularly have significantly high levels of lead and cadmium in their bodies. The report reveals a study of more than 7200 users in a nationwide survey between 2005 and 2018. Levels of five metallic contaminants were found in the blood and 16 in urine.
Marijuana is the third most commonly used drug, behind tobacco and alcohol. Like the tobacco plant, the cannabis plant is a “hyperaccumulator” of metals according to Katlyn McGraw a researcher at Columbia University in New York. Cannabis and hemp are good at cleaning up soil, and accumulate toxic contaminants, according to Harvard Medical School researcher Dr. Peter Grinspoon. The plant absorbs heavy metal from the soil and deposits them in the leaves, stems and buds. When smoked, these metals are aerosolized and deposited in the lungs and blood and thereafter in other organs and tissues. Additional concerns are that of similar transmission of pesticides, mold, fungus and residual ground solvents.
It is well known that lead toxicity, primarily from lead based paint can alter development of the nervous system in those exposed. Marijuana use during adolescence can alter brain development and create mental health impacts including depression, anxiety and psychosis. Driving under the influence of marijuana can be dangerous although not from heavy metal exposure. Unintentional exposure to children and pets from marijuana smoke can be harmful. Marijuana use during pregnancy has been reported to result in developmental problems both prior to and after birth.
Some researchers are thus advocating for legalization of marijuana use which hopefully would lead to regulations regarding growth of the plants and testing to assure minimal contamination with toxic substances.
What does this mean with respect to your eyes? Well for years marijuana has been touted as a good treatment for glaucoma, damaging pressure elevation in the eyes that may cause loss of vision and even blindness. Although proven much less effective than originally thought, the easing of restrictions for medical use and legalization in some places may encourage its use without due concern for the potential side effects. There is ongoing research to detect as yet unidentified toxicity in the eyes.