It is estimated that there are as many as 10 million contaminated sites around the globe, with over half of those sites involving heavy metal contamination specifically. Heavy metals are metallic elements that have a relatively high density compared to water, and heavy metal contamination involves soil (and water) being saturated with heavy metal pollution over time.

Some of the most common types of heavy metals found at contamination sites that are concerning to humans include cadmium, chromium, mercury, lead, and arsenic. Contamination sites can be found at old geogenic, industrial, agricultural, pharmaceutical, domestic effluents, and atmospheric locations.

In addition to harming humans, heavy metal contamination also negatively impacts wildlife and the environment. It can lead to a number of health issues, including disease and even death. If sites contaminated by heavy metals are not properly cleaned up in a timely manner, contamination can extend to local water sources.

Hemp To The Rescue

A major tool at the disposal of humans is the hemp plant. Per one of many studies on the subject, hemp plants have an uncanny ability to absorb heavy metals from the soil in which they are planted. It’s a two-edged sword, in that heavy metal fertilizers are commonly used by some cannabis growers and that is not a good thing. However, for the purpose of cleaning up contaminated sites, hemp’s ability to absorb heavy metals is incredibly useful.

Due to the stigma of the hemp plant, its use for cleaning up contaminated sites is still somewhat limited around the globe, although the practice is currently being put to use in some places. For instance, hemp is planted around the site of Europe’s largest steel plant in Italy to clean up the area’s contaminated soil.

Hemp matures notoriously faster compared to many other plants and trees that have strong heavy metal uptake abilities. It takes roughly 3-4 months for a hemp plant to grow from start to finish, and throughout its growth process, it is pulling heavy metals from the soil that it’s planted in. It’s an environmentally friendly way to clean up sites efficiently. As the political stigma surrounding hemp cultivation subsides around the planet, it’s a technique that will likely increase in popularity.

What About The Hemp Harvests?

One obvious question that people ask when the topics of hemp and contamination sites come up is ‘what do they do with the harvested hemp?’ It’s a logical question, and thanks to recent research out of Belgium there’s now some insight regarding an answer.

A team of researchers in Belgium recently planted hemp in contaminated soil for the purpose of testing the contamination levels of the hemp itself. The researchers wanted to know if the hemp fibers could still be used to make textiles even though they came from plants that were used to decontaminate polluted soil.

“…both Cd and Pb concentrations in the fibers were far below the heavy metal thresholds for textile product safety in all cultivars, while Zn is not considered toxic in textile production. In addition, low Pb, Cd, and Zn concentrations in the shives suggest the potential safe use of this residual fraction of hemp fiber production as well.” the researchers stated.

“These results are promising in terms of safe use of the produced hemp fibers in the textile industry and thus of the potential valorization of contaminated land through hemp cultivation and the development of non-food value chains within a phytoattenuation strategy.” the researchers concluded.

It is worth noting that this particular study only looked at contamination levels as they pertain to textiles. Hemp can obviously be used to make foods and other consumables, including ones that people inhale, and further research is needed regarding hemp harvests at contaminated sites and whether or not the harvests can be used for things that humans ingest/inhale.