A new study carried out by Penn State researchers discovered that cannabis plants may suck up heavy metals through soil, water and air absorption.

Published in Toxin Reviews, the study honed in on the use of various cannabis strains for the removal of pollutants from air, soil and water — a process known as phytoremediation.

However, when used for phytoremediation purposes, the rate of heavy metal absorption is amplified.

“Heavy metals, such as lead, mercury, cadmium and chromium, are known to be carcinogenic,” said assistant research professor of plant science at Penn State, Louis Bengyella.

Cannabis’ heavy metal content is not regulated

Although heavy metals naturally occur in the earth’s crust, they are no friend to human health and, if consumed, may even be life-threatening. In particular, cancer patients who rely on cannabis to relieve the side effects of treatment have been warned of the dangers associated with heavy metals.

While medicinal-grade cannabis has exhibited potential for diminishing widespread ailments, including appetite loss, pain and nausea, it’s important to understand a product’s source and the processing it undergoes prior to sale/consumption.

“The heavy-metal content of cannabis is not regulated; therefore, consumers could unknowingly be exposed to these toxic metals. This is bad news for anyone who uses cannabis but is particularly problematic for cancer patients who use medical marijuana to treat the nausea and pain associated with their treatments,” Bengyella added.

How can cancer patients benefit from this study’s outcome?

After careful analysis of different cannabis strains, the team of researchers found that cadmium, chromium and lead were easily dispersed and transferred to the plant’s flowers and leaves via the stalk.

“It is disturbing to realize that the cannabis products being used by consumers, especially cancer patients, may be causing unnecessary harm to their bodies,” said Bengyella, who drew attention to the fact that smokable cannabis carries the biggest risk of heavy metal contamination. 

Consumers ought to pay close attention to their source, adds Bengyella, since some sellers may not follow protocol when it comes to testing their products for heavy metals; among many other contaminants. Conversely, the study authors say that home growers should steer clear of certain practices so as to reduce the overall risk. 

“Avoid abandoned industrial sites, perform air quality analyses before establishing a farm, and conduct a soil pH test because pH can impact the quantity of heavy metals a plant absorbs,” were the three suggestions that the study authors offered their readers.