Italian farmers reclaiming land around a dioxin contaminated steel plant are the latest to use hemp to cure the land itself.

The technique is called “phytoremediation.” It means using plants to remove contaminants, like heavy metals or radioactive material, from polluted soil. It turns out cannabis, hemp in particular, is one of the best crops ever for this task. This month the Italians and the Pennsylvanians are the latest folks to make the news by using cannabis in this unique way.

While the principles have been known to farmers for thousands of years the technique first caught the attention of modern audiences after the 1986 Chernobyl incident. Dr. Ilya Raskin of Rutgers University’s Biotechnology Center for Agriculture and the Environment was brought in to assess the level of radioactive contamination in the area and determine a method to cleanse the environment. Originally, Raskin preferred mustard greens as the plant to draw the radioactive Strontium 90 out of the soil, but by 1998 the Ukrainian government had researchers planting cannabis to absorb the fallout and the practice began to popularize.  The process was widely discussed as a cure for Fukushima as well.

“Industrial hemp has been used in areas of high radiation, such as Fukushima, with promising results. Not only does hemp pull toxic, heavy metals from the soil but it actually improves soil structure making it usable as productive farmland again. Plus, hemp is a vigorous plant that absorbs CO2 rapidly, making it an encouraging solution to climate change” –Allison Beckett, Marijuana.Com

Though the word “phytoremediation” isn’t that common, the method was back in the news last week after CBS discovered Italian farmers in Taranto received government blessing to reclaim land around a dioxin contaminated steel plant by planting cannabis. In 2008, the government shut down the steel mill and shuttered the region’s dairy industry. The contaminated lands were contaminating the milk the cows produced. Thus the hemp.

As with Strontium 90 or other heavy metals, the root chemistry of the hemp plant not only absorbs the dioxin contaminants, soil microbes aid the hemp in transforming the toxins into harmless plant material. The same week, Petroleum News noted University of Alaska professor, Mary Beth Leigh released a study recommending phytoremediation for petrochemical spills in the Arctic. Back in Italy, after the Taranto lands are rehabilitated, local farmers hope to go back to their centuries-old dairy tradition. In the meantime, as a result of Italy’s support for hemp, hundreds of Italian products are now being manufactured from Italian hemp, everything from tennis shoes to apartment complexes.

Lastly, phytoremediation made its way into American news this week as part of Pennsylvania’s new embrace of all things cannabis. In addition to launching a state medical marijuana program this week, the Keystone State also awarded grants to 16 hemp research projects on March 23rd. The Pennsylvania Hemp Industry Council will be working with Lehigh University on one of two hemp phytoremediation research projects that landed a grant. The Lehigh project will create a complete hemp research institute on the campus and develop methods to reclaim some of the industrially polluted lands in Lehigh and Lycoming Counties. The other project in Berks County will be co-sponsored by gardening giant, The Rodale Institute.

READ MORE: Farmers in Italy fight soil contamination with cannabis by Seth Doane, CBS News