by Seshata on 25/12/2013 | Cultivation

Hemp and the Decontamination of Radioactive Soil

Hemp and phytoremediation Hemp science is now advancing in leaps and bounds compared to the stagnation of the previous few decades. One significant area of research that is currently receiving particular attention is phytoremediation, or decontamination of soil—although the fact that hemp decontaminates soil has been known for some time.

The Chernobyl phytoremediation project

For over a decade, industrial hemp growing in the environs of the abandoned Chernobyl nuclear power plant in Pripyat, Ukraine has been helping to reduce soil toxicity. Now, the Japanese are considering following the same course in order to rectify the environmental damage caused by the Fukushima meltdown—however, due to the Cannabis Control Law forced into Japanese law by the occupying U.S. powers in 1948, hemp may only be grown under license – and these are highly restricted and difficult to obtain.

In 1989, just three years after the initial explosion, the Soviet administration of the time requested that the International Atomic Energy Agency (IAEA) assess the environmental situation. In the 30km exclusion zone surrounding Chernobyl, high concentrations of various toxic metals including iodine, cesium-137, strontium-90 and plutonium were found in the soil, as well as in plants and animals.

Hemp and the Decontamination of Radioactive Soil - Sensi Seeds Blog
Hemp has been found to decontaminate soil at a very high rate

Which Plants are Useful in Phytoremediation?

In response, it was decided that a concerted effort to reduce soil contamination through the use of beneficial plants would be undertaken. This process, known as phytoremediation, began immediately, and used various plants to take up specific contaminants—two brassica varieties to remove chromium, lead, copper and nickel, maize to take up lead (various researchers have demonstrated the remarkable lead-uptake capability of this important crop), and more recently, sunflower and hemp.

Sunflower plantings began in 1996 subsequent to the development of a variety that promised hitherto unheard-of efficiency of decontamination; hemp plantings soon followed, in 1998. Slavik Dushenkov, a research scientist with Phytotech, one of the organisations behind the hemp plantings, stated that “hemp is proving to be one of the best phyto-remediative plants we have been able to find”.

Hemp as a soil decontaminant

As well as in the Ukraine, much rural land in neighbouring Belarus was affected by the explosion, and authorities there are also pursuing the use of hemp as a decontaminant. The harvest produced will be turned into ethanol, as increased production of biofuel is a key target for increasing the overall economic and environmental health of the region.

 Hemp and the Decontamination of Radioactive Soil - Sensi Seeds Blog

The Chernobyl exclusion zone, site of the world’s worst nuclear disaster, is slowly being returned to health as plants and animals begin to reclaim the land

Different hemp strains show different uptake of contaminants in soil

In 2012, a Romanian study investigated the nutritional safety of hemp seed produced from plants grown in soils rich in calcium, magnesium, potassium and iron. The study determined that five distinct Romanian hemp strains developed different nutritional profiles according to uptake of the various metals in the soil. For example, the Zenit strain exhibited highest rates of calcium uptake, while the Armanca absorbed least calcium; the Diana, Denise and Silvana strains absorbed magnesium at the highest rates, and the Zenit variety showed the highest concentrations of iron.

Despite the differences, the seeds and oil of all five strains exhibited high levels of magnesium, calcium, iron, manganese, zinc and potassium, all highly beneficial dietary metals. However, all varieties also tested above the safe legal limit for cadmium. This is a toxic heavy metal that may cause various health complications—despite the soil being within the safe limit for cadmium concentration. The Armanca and Silvana strains showed particularly high cadmium levels.

Hemp and Cadmium Absorption from soil

Excessive consumption of foodstuffs high in cadmium can lead to joint and bone deformities, respiratory illness, anaemia, and kidney failure. In areas where cadmium is present in the soil, in order to be safe for human or animal consumption, hemp varieties should be selected on the basis of poor cadmium uptake.

According to a study into Chinese hemp strains conducted in 2011, many hemp strains have the ability to absorb and accumulate even large quantities of cadmium in soil without detriment to the plant itself. While this does throw up various implications for selection of sites for cultivation of food-safe hemp, it also indicates that cadmium-contaminated sites will particularly benefit from phytoremediation schemes that make primary or exclusive use of hemp. Furthermore, even if hemp used to decontaminate soil is unsafe for consumption, it can still be used in a number of industrial applications, such as for biofuel.

Hemp and the Decontamination of Radioactive Soil - Sensi Seeds Blog
As vegetation slowly reclaims formerly inhabited areas, adding species such as hemp to decontaminate the soil can aid in ecosystem rejuvenation

Hemp is Mostly Unaffected by Heavy Metals in Soil

Hemp’s resilience to contaminants in soil is well-documented. Even as early as 1975, a study published in the Agronomy Journal described how soil characteristics influenced elemental uptake and could even affect final cannabinoid profile in psychoactive strains. To illustrate this, fifteen sites with varying soil profiles were planted with the same strain of Afghan cannabis. Their harvests  were tested for metal content. Researchers concluded that differences could be used to determine geographic origin of cannabis through foliar analysis.

In 1995, the Polish Institute of Natural Fibres released a study demonstrating that tested varieties were able to withstand high levels of heavy metals in soil without impacting plant growth, yield or fibre quality. However, little research has been done into the safety of using fibres in clothing or other forms of industry. This issue must be investigated fully in order to establish the possible uses for hemp grown in such conditions.

Hemp could benefit hundreds of thousands of contaminated sites

As a proven, valuable tool in the fight to repair human-inflicted damage to our soils and ecosystems, hemp could potentially benefit hundreds of thousands of sites across the globe. It is estimated that in the USA alone there are 30,000 sites requiring remediation. As is so often the case, US restrictions on hemp cultivation preclude any large-scale operations from being implemented. The contaminated sites are largely left unremediated, through lack of both funding and interest on the part of the government.

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Excellent article Seshata! Paired with Paul Stamets use of fungi as a bio-remediation tool, this looks to be an excellent way to teach stewardship of our land and resolve the mistakes we have made as a species so far. Thanks for the research!


Moseley Putney, AIA

I am founder of Kentucky Hemp Industries and am looking for scientific data/studies on hemp utilized for phytoremediation. Any assistance will be gratefully received.


Scarlet Palmer

Hello Moseley, thank you for your comment.
It is possible that articles on the Hemp Industries Association website might be useful for you ( and the Hemp Cleans initiative was also doing research into phytoremediation last year ( If we find any studies dedicated to this, I will get in touch again. Good luck with Kentucky Hemp Industries, more power to your elbow! With best wishes, Scarlet


MOhemp Energy

Mr Putney the local team is working on StLouis nuclear decontamination of the old Manhattan Project Nuclear waste burried in a landfill (Westlake and Bridgeton) as well as along the Cold Water Creek areas. see: for pot testing info and future plans.


You need not know me

Does that mean radioactive superweed is impossible?



This is great information and it suprises me that legislation is preventing the clean up in Japan as that is an environmental disaster according to some intelligent physicists. Has anyone done any research on what happens when you burn the hemp in bio diesel? Wouldn't the chemicals the plants absorb in the ground cause these metals to be released into the air? I am not a scientist and hope I don't sound ignorant on the subject. The reason for my questions is that I am interested in cleaning up a large piece of ground I have from high levels of arsenic from farming. Thanks in advance for responding:)



Hi Joey, apologies for the delay in responding. Disposal of accumulator plants is a tricky issue, and if levels of heavy metals are beyond a certain threshold they are considered toxic waste and must be disposed of accordingly. How this applies to hemp has not been ascertained, as far as I'm aware, although I will update if I find anything specific to it. This article ( has some interesting links to further reading.


Lo Jarl

Working partly in the field of functional medicine it is sometimes demonstrated through Hair Tissue Mineral Analysis that people who are keen on hemp in all its forms jave high levels of heavy metals such as Cadmium, Uranium, Arsenic and Lead and possibly other metsls as well. This may imply that those manufacturers involved in hemp produce have poor control of the soil conditions where the hemp used for human consumption and clothing is being cultivated. Does anyone know of certification labels setting the standards for hemp produce low in heavy mrtals? We have to remember that some soils may naturally be high in heavy metals, or various natural soil improvement rock products. So simply avoiding industrially polluted soils will not guarantee that hemp (very often) labelled as organic or environmental friendly, will have acceptable levels of heavy metals.



Hey, this is interesting, thank you for bringing it to my attention. I will have to look into the existing guidelines, I haven't come across anything regarding levels of heavy metals in soil yet but there could be some non-specific guidelines that still apply. These results of the Hair Tissue analysis - are they available to source online in any form, or could you make them available?





I don't understand why this information isn't more available.
I have researched some things online about hemp and cancer killing properties and it got me to thinking about the rise in the legalization of Marijuana in some states and the growing of hemp threw the farm bill soon after the fukushima incident call me crazy but I really think there may be a connection here



I have also wondered about the accumulation of heavy metals during the bio-remediation process. Have there been any experiments attempted? Conceptually, much could be learned using spectrum analysis processes. There is also the possibility of re-processing as a bio-fuel. Would the metals break down further under combustion or would they remain as airborne contaminants? Much science to be accomplished here.

Excellent article, BTW.



Where do the radioactive plants go once they've absorbed the radio nucleotides? Another
potential problem? In a debate: hemp deactivates radiation. I say hogwash.


Seth Hartley

two questions come up for me, and I'm more just throwing them out there instead of looking for answers.

1. Could repeated remediations spread and diffuse heavy metal levels until they are balanced and under toxicity threshold levels? for example, planting in a toxic area, using the biomass produced for compost fodder or wormery feed, then re-planting until the metals are dispersed over a less concentrated area?

2. There was some mention about toxic ash from burning, but would you have the same results from pyrolysis (gasification)? Would heavy metals transfer to syngas, or would they stay with the bio char, and thus once again be used as an additive to diffuse the metals in small amounts into non-toxic soils?

3. I also saw mention of stamets and mycoremediation. Perhaps use hemp to isolate metals from the soil into biomass, then mushrooms to further process them until either more stable or uniformly distributed?

My interests would specifically be in bio-remediation of fly ash in desert conditions. It would be helpful for presenting to the local college's agroforestry branch as a project.



Thats great news, it seems to be a versatile plant that can do good.


Real Lehoux

I have serious doubt that any plant could effectively decontaminate a area highly radiactive.
Explanation: I do agree that plants have different absorption rate of different elements.
What must be understand is some Radiactive elements decay rapidly and loose their radioactivity in weeks , months and years dependant of their activity and molecular weight as example Radioactive Iodine decays fast in days and week but Plutonium takes 100 thousands of years to decay from dangerous level to more natural one. When a plant absorb a radioactive substance it maybe a low level one or a high level but in both case absorption does not change the rate of decay. An advantage is that plant could fixe into their cells the elements therefore in large quantity of plants the radioactive dust is not spreading elsewhere/everywhere.


Guadalupe Rivera

I would lije to know whrre can i get seeds
i live plants any kind and love to grow them



Excellent information. Why the big nations are not taking any initiative to reclaim the soil.? People are more worried about their personal gains than this. Soil contamination is a serious problem that too with radioactive materials.


Janine boguslawski

Thanks for the research. Very interesting artcle.


Dave Hicks

Great article.

I'm working with my KS state rep to pass a hemp bill this session legalizing the plant.

How are plants used for phytoremediation disposed of? I assume they are not useable in any manner.




Yes this is something we are just starting to put together. I feel that one bio remediated product such as hemp could be remediated by mycoremediation. Exciting times! Unfortunately there is a lot of toxic soil out there. Most organic soil could be first remediated by hemp.



Hey, could you please cite your references and sources for this report?


Scarlet Palmer

Hi Shanthanu,

Thank you for your comment. I've just checked through this article and all the links (in green) to sources are working, apart from the first one and the last one. I will contact Seshata, the author, and ask if she has additional sources that can be linked to instead. I hope this helps :)

With best wishes,



John J Arredondo

Enjoying all this great information


Mike Tyler

The waste now is radioactive and the only current method research has come up with so far is spread it out evenly? Has science overlooked a natural means to contain and destroy this particular absorbent safely ? Can we send waste down VERY DEEP HOLES in the Earths crust? The technology to do so is available and there are some holes that already exist that go several miles down.


Jarrod Mcbay

Could you extract the radiation after the hemp has absorbed it and some how reuse the heavy metals and radioactive materials be repurposed some how? And would the plant material be at a safe level to compost?



Do anybody know which plants absorbs more iron from soil ?



What happens to the hemp plants that are used to help decontaminate the soil around Chernobyl? I would tend to think that any radioactive elements will remain that way according to half life values whether in the soil, a plant, or in the air if the plant is burned as some sort of fuel, converted or not. Maybe the plant can be processed to put some of the scary genie back into a bottle to be stored on a shelf for a few thousand years. Still the problem of what do you do with the leftover plant products? Does anyone test for radioactivity in cannabis/hemp products for human use or consumption? And if so, what would be safe levels? There are places on earth where levels can be naturally higher than others, along with the messes mankind can be attributed to. Just another concern to add to heavy metals and other toxins.


gary york

Too funny that hemp adobe building material used in extremely green homes uses magnesium as a "glue" or binder for its strength. I say grow the strain that takes up the most magnesium to kickstart what is added later? Ive been a hobby cannabis breeder for about 45 yrs now. Maybe the hemp protein I eat now is pulling out mercury from my 35 yrs of eating albacore tuna? hope so....


You need not know me

So is radioactive superweed impossible?


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