Article by Andrew Leonard, Rolling Stone
In 2017, Gavin Stonehouse, a graduate student in plant biology at Colorado State University, started cultivating hemp plants in a special soil mixture dosed with varying levels of selenium. A mineral that occurs naturally in most of the western United States, selenium is also a nasty environmental pollutant when produced in excess by industrial and agricultural activities.
Stonehouse wanted to find out if hemp could handle the selenium. If the plants thrived, it would be an important first step towards proving claims that industrial hemp naturally cleans soils contaminated with a multitude of toxic substances – a process known as “bioremediation” or “phytoremediation.” The next step will be to discover just how much of the selenium the plants extract, and where the mineral ends up – in the plants’ roots, stems, seeds or flowers.
Stonehouse and his advisor, CSU professor Elizabeth Pilon-Smits, plan to publish their results this summer. But the early indications are promising. The hemp was “super tolerant” of the selenium, says Stonehouse. Not a single plant died, and only a few, exposed to the highest doses, showed signs of stress.
The implications of the experiment go beyond just the potential for healthier soil. As humans have known for thousands of years, hemp is a plant that boasts abundant industrial, nutritive and medicinal properties. You can eat its seeds, treat pain and inflammation with its oils and make clothing, rope and paper from its fibers. And now, in the 21st century, we’re discovering that it can perform like a kind of a toxic-substance vacuum cleaner too?
“If you can clean up the environment and still get a commercial product,” says Stonehouse, “you are killing two birds with one stone.”
The term “phytoremediation,” was coined by the scientist Ilya Raskin, a member of a team that tested hemp’s ability to accumulate heavy metals from soil in contaminated fields near Chernobyl in the 1990s. According to another team member, Vyacheslav Dushenkov, the experiment was a success. “For the specific contaminants that we tested, hemp demonstrated very good phytoremediation properties,” says Dushenkov,