By Kim Robson:
Cleaning up toxic chemicals and heavy metals from soil is generally an onerous, expensive and time-consuming task involving chemical and mechanical processes. In my tiny mountain community of Julian, there’s long been an empty lot growing weeds on the corner of a busy intersection. Surely some developer would love to build there, but none have. The reason? There was once a gas station there, long ago before many environmental regulations were in place, and the soil is deeply contaminated. No one wants to spend the money to clean it up
But there is a greener way to clean up sites like these. Certain plants are known for their ability to naturally “scrub” toxic soil and groundwater. Phytoremediation is the deliberate use of these plants to remove contaminants from soils, sludges, sediments, surface water and groundwater. Phytoremediation can pull nuclear elements, heavy metals, pesticides, solvents, crude oil and other toxins from landfills. Compared to traditional methods, it’s an affordable and ecological alternative for soil remediation. Hemp breaks down pollutants and stabilizes metal contaminants by acting as a natural filter.
Studies have shown industrial hemp (with little to no THC) to be one of the best of these plants. In Italy’s Puglia region, farmers are growing hemp to pull heavy metals out of soil near a massive steel plant. The soil around the plant had been so heavily contaminated that for decades farmers were forbidden to allow their animals to graze within a twelve-mile radius of that area.
Hemp is ideal for phytoremediation because it grows quickly, has deep roots, and is unhurt by the toxins it accumulates from the soil and air. Cadmium, a heavy metal and major soil pollutant, can be eliminated simply by growing hemp.
Hemp can even pull radioactive nuclear toxins from the soil. It’s been planted near and around the Chernobyl nuclear disaster site to pull radioactive elements from the ground, and may be used to help clean up the area near the Fukushima nuclear disaster. In addition to cleaning the soil, hemp also acts as a carbon sink, reducing greenhouse gases.
Hemp can grow in virtually any agronomic system and climate, and requires no fertilizer, herbicides, pesticides, fungicides or insecticides to grow well. However, once phytoremediation hemp has been harvested, it should not be used for consumption as food or medicine, but it can safely be used as fuel. Using hemp as biomass fuel to make charcoal could eliminate the need to burn coal. Hemp biomass burns with virtually no sulfur emissions or ash, which eliminates the acid rain caused by burning coal.
Even without the need for soil remediation, at a minimum hemp crops make an excellent rotation crop. As hemp stabilizes and enriches soil, and prevents weeds without costly herbicides, even if none of the plant being harvested is used, it still has enormous value. Rotating soy fields with hemp reduces cyst nematodes, a soy-decimating soil parasite, without any chemicals added. Marginal lands make fine soil for hemp, and hemp can be grown between growing seasons.
Paper, rope and cloth can all be made from tough, fibrous hemp. With more and more states accepting medical marijuana and even recreational use marijuana, surely we should wake up to the countless possibilities for industrial hemp as well.