Hemp as a Phytoremediator: Here's What We Know

Kaitlin Domangue

Do you know what phytoremediation is? Put simply: it’s when plants are planted to clean the earth around them. For a long time, humans have polluted the earth without doing a lot to clean up after ourselves. In turn, the earth has suffered and so has our food chain. If we are growing plants in contaminated and heavy-metal laden soil, what might our food absorb? 

Hemp as a phytoremediator

Hemp is a phytoremediator, so it will successfully clean the earth’s ground. Hemp is not the only plant with these capabilities, but as a hemp farm and CBD company - that’s our focus. According to an in-depth article by Cannabis Tech, phytoremediation has been shown to absorb: 

  • Heavy metals
  • Pesticides (including herbicides and fungicides)
  • Radioactive elements
  • Explosives
  • Fuels
A hemp leaf, a phytoremediator, being held in front of a blue sky

There are three main ways phytoremediation takes place. There are a few additional ways, but here are the three most discussed: 

1. Phytoaccumulation

Phytoaccumulation simply means the plant accumulates toxins and stores them in the shoots and leaves of the plant, where they will remain until the plant dies. Namely, phytoaccumulation absorbs heavy metals like nickel, zinc, lead, and even arsenic! 

Studies show hemp can accumulate heavy metals without much damage to the plant itself, but this study in particular says the mechanisms by which accumulation takes place isn’t exactly known. “Hemp’s short growing cycle, decreased need for pesticides, and low plant maintenance makes it an ideal candidate for phytoremediation studies,” concludes the study.

2. Phytovolatilization

Through this process, the plant will absorb organic contaminants but unlike heavy metals, they won’t be stored in the plant. Once they are absorbed, they will be released through the leaves and into the air. 

Hemp plants on the farm at sunset, planted to be a phytoremediator in the organic soil

3. Phytodegradation 

The photodegradation process will allow plants to absorb harmful compounds from the soil, but they metabolize and degrade instead of storing in the plants or releasing. 

Italian farmers plant hemp in a phytoremediation experiment 

Italian farmers made the headlines a few years back for planting low-THC cannabis on their now-empty sheep farm. The reason? A toxin called dioxin was leached from a factory just one mile away and into Vincenzo Fornaro’s farm, forcing him to slaughter his entire herd. It was a devastating blow, and because of that, he couldn’t ever have grazing animals again. So, in an experiment, he planted hemp, and now he feels cannabis is the future of his Italian farm. 

Organic farmer's hands planting a hemp plant in the organic soil to be a phytoremediator

Hemp cleans Chernobyl

Hemp was also planted at Chernobyl, one of the most toxic waste zones in history. One of the scientists working at the site, Ilya Raskin, coined the term “phytoremediation” after seeing how much it helped. In 2001, a team of German researchers were able to confirm that hemp did indeed remove contaminants from Chernobyl, including lead, nickel, and cadmium. 

So, what’s preventing us from throwing hemp everywhere and cleaning the earth? Until very recently, it was still illegal in the United States. In 2018, the federal government passed the 2018 Farm Bill which removed hemp from the Schedule I Substances list and allowed for commercial cultivation of the plant. This opened the floodgates, and now hemp is being looked at more and more for incredible reasons like phytoremediation. 

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