Many cannabis users think of it as a very safe medicine—the side effects are few, the risks are low, and it comes straight from a plant. While this is generally true, cannabis is not without health risks—not because of anything wrong with the plant itself, but because of how it may be grown. Like any other plant, cannabis can be contaminated by bad things in the surrounding air and water, including mold and mildew, mites, bacteria, pesticides, and heavy metals.
Today, we want to take a look at that last one—heavy metals—and explain what it means and why it’s bad for you.
The “heavy metals” that are a risk in agriculture include arsenic, cadmium, lead, and mercury. They get into outdoor plants mostly from pollution and runoff, but they can contaminate indoor plants, too, when growers use fertilizers and pesticides that contain these dangerous metals. What’s so bad about them? Let’s take a closer look:
Arsenic: Arsenic is poisonous to humans and has often been used to commit murder and suicide. In toxic doses, it causes violent vomiting and diarrhea; cold, clammy skin; reduced blood pressure; and eventual death from lack of blood flow. It is a known carcinogen linked to many different kinds of cancer. While we all are exposed to small doses of arsenic all the time, larger doses are extremely dangerous.
Cadmium: Cadmium is a zinc byproduct used in manufacturing. It is extremely toxic and carcinogenic. According to OSHA, cadmium “targets the body’s cardiovascular, renal, gastrointestinal, neurological, reproductive, and respiratory systems.” It gets into the air mostly from burning fossil fuels, and causes lung irritation when inhaled. Large amounts of cadmium can cause kidney disease because the body can’t process it completely.
Lead: Another famous poison, lead can cause extremely serious health disruptions, especially in children, who may experience developmental delays and learning disabilities. In adults, more common signs of lead poisoning include headaches, intestinal distress, joint and muscle pain, and reproductive issues. While it’s no longer used in paint or pencils, lead is still a common contaminant in the air and soil.
Mercury: Organic mercury, which is a byproduct of fumes from burning coal, can cause serious neurological damage, including pain and numbness, tremors, difficulty walking, memory problems, and even seizures.
Of course none of us wants our medicine to be contaminated with these metals, but it can be hard to know if the cannabis you get at the dispensary is free of heavy metals or not. Lack of uniform regulations means that testing requirements vary from state to state. For example, the State of California doesn’t require safety testing, but some municipalities do. Colorado, bizarrely, requires safety and potency testing for recreational marijuana but doesn’t require any cannabis testing for medical marijuana. Washington State requires testing for potency, mold, microbial agents, and heavy metals.
Independent labs dedicated to patient safety have sprung up to fill this void, and high-end cannabis dispensaries only carry products that have been thoroughly tested for potency and safety. But many of these labs stop short of testing for heavy metals.
How do you ensure your medicine is not contaminated with arsenic, cadmium, lead, or mercury? First, ask your budtender to show you products that have been tested for heavy metals. If none have, maybe you should consider a different dispensary. Second, be aware that concentrates such as wax and shatter are likely to have not only heavier concentrations of THC, but also of heavy metals, so you may be better off with buds/flower. Third, find out what the testing laws are in your state and, if you don’t think they’re good enough, let your legislators know.
Finally, if you need help finding safe cannabis products, set up a consultation with United Patients Group. We have evaluated many cannabis products and selected the very best ones, and we can recommend brands that prioritize safety. Because all patients deserve access to safe cannabis that is free from the risks of heavy metals.